Q & A > Question Details
What are the most important automation and control components being incorporated into new projects to help operating companies increase capacity and meet higher quality specifications while reducing recycle and energy costs?
23/04/2008 A: Amarjit Bakshi, Refining Hydrocarbon Technologies LLC, abakshi@rhtgulfcoast.com
Computer control with feedback control schemes together with putting other variables for unit operations can be input into the computer control software so as to get the desired product slate and operating conditions to achieve the best yield and selectivities. The analysers are integral part of these schemes.
21/07/2007 A: Eric W Hennings, Stone & Webster Engineering Corporation, eric.hennings@shawgrp.com
On new process units, instruments are provided to accommodate the complete range of potential computer controls. These include conventional primary elements as well as more dynamic instruments such as delta P. These are further supplemented by analysers where appropriate. Note that analysers often include special sample conditioning and maintenance features. As refiners move into petrochemical production such as propylene, the use of analysers in the trace-contaminant range becomes more important.
21/07/2007 A: Michael Sharpe, Foster Wheeler Energy, michael_sharpe@fwuk.fwc.com
Performance-monitoring systems combined with condition monitoring systems are being selected by some projects to provide improvements in the efficiency of mechanical equipment during operation and to supply data to facilitate predictive maintenance regimes. These systems can be used to both optimise energy use and improve the operating efficiency of rotating equipment. Examples of the type of information provided are indications of build-up within exchangers, blade deposit build-up on steam turbines and overall efficiency/energy cost data on machinery operation. These systems supply on-line data to enable operating conditions to be adjusted to provide overall better quality product and optimise the use of utilities such as electricity, steam and fuel. These systems also store historical data on operating conditions of equipment together with built-in intelligence, which can be used to predict maintenance requirements and allow informed decisions to be made on the timing of equipment shutdowns, thereby reducing down-time and ensuring that the appropriate spares are available. Operator training simulators (OTS) provide the means to train operators into the operation of the plant in an offline situation. The use of a simulator can enable operators to be prepared for unusual plant conditions, thereby increasing the likelihood that if these occur in real life a potential plant trip can be averted. OTS can also provide an extra benefit in identifying areas of complex control schemes that could be improved before the plant is operating, due to the plant and control simulation included. This can reduce commissioning time and give the benefits of on-spec product earlier. Instrument asset management systems are being used more extensively in Foster Wheeler’s current projects. The benefits to maintenance and the related reduction in operating costs and increased reliability are generally well accepted. The combination of these systems together with the use of Foundation Fieldbus technologies offer significant advantages not just for an operating plant, but also in streamlining the testing and commissioning of instrument systems at site. These systems provide diagnostic information, enabling the quick closeout of instrument faults, minimise the number of false instrument technician call-outs, and reduce the amount of unnecessary shutdown maintenance required on valves.