Modeling and fault monitoring of industrial centrifugal equipment

旋转机器的振动会对其部件造成极大的压力和损坏，导致故障率增加。在高速运行的大型离心机中，例如用于分离液体和固体不同物料的钵式离心机，由于重力极大，钵和转子的不平衡会导致灾难性的情况。对这些机器来说，在全速运转时及早发现不平衡是至关重要的。另一方面，即使在正常运行条件下，随着旋转频率接近系统振动模态对应的临界频率，启动和关闭过程中的振动水平也会发生显著变化。不考虑滑行过程中预期的较大振动的停机条件可能导致潜在的损坏或故障。这些碗型离心机已广泛应用于加拿大的油砂工业，在石油开采的几个阶段进行关键的油分离过程。它们的可靠性对生产和成本有着重要的影响。为了降低成本，提高油砂的市场竞争力，提高设备的可靠性是油砂企业的首要任务。因此，提高离心机运行的可靠性和效率是本研究的一个重要目标。为了实现这一目标，本研究确定了几个短期目标：1)对离心机的动态行为进行建模和表征；2)设计并实现了基于模型的离心机状态监测方案。通过实现这些目标，我们进一步致力于开发有效的旋转机器建模工具，特别是像碗型高速离心机这样的垂直旋转机器。

Vibrations of a rotating machine can cause extreme stress and damage to its components, leading to increased failure rate. In a large centrifuge operated at high speed, e.g. a bowl type centrifuge used to separate different materials of liquid and solid, imbalance of the bowl and rotor can result in disastrous conditions due to the extremely large g-force. Early detection of imbalance during the full speed operation is very crucial for these machines. On the other hand, even at the normal operating conditions, the vibration level during start-up and shut-down varies significantly as the rotational frequency approaches the critical frequencies corresponding to the vibration modes of the system. The shutdown condition not considering the larger vibrations to be expected during the coast-down process can lead to potential damages or failures. These bowl type centrifuges have been widely used in the oil sands industry in Canada to perform the crucial oil separation process in several phases of the oil extraction. Their reliability plays a major role impacting the production and cost. To lower the cost and make oil sands more competitive in the market, it is of top priority of the oils sands company to enhance the equipment reliability. Therefore, one important goal of this research is to improve the reliability and efficiency for operating these centrifuges. For this goal, several short-term objectives are identified for this research: 1) to perform modeling and characterization of the centrifuge dynamic behaviors; 2) to design and implement model based condition monitoring scheme for these centrifuges. By accomplishing these objectives, we further aim to develop effective modeling tools for rotating machines, especially for the vertical rotating machines like these bowl type high speed centrifuges.