DCS / PLC - based Advanced Process Control (APC)
DCS / PLC - based Advanced Process Control (APC)
PiControl Solutions LLC has extensive skills and experience in DCS/PLC-resident advanced process control (APC) design and start-up using the existing DCS/PLC or even build the advanced process control (APC) logic on a new PLC attached to the existing DCS/PLC system.
Many times, DCS/PLC-based advanced process control (APC) can be superior, achieve more monetary benefits and outperform a model predictive control (MPC) or any other advanced process control (APC) technology. After detailed process analysis, PiControl can easily and honestly recommend which control logic will give the best achievements: DCS-resident advanced process control (APC) or model predictive control (MPC, like DMC/RMPCT).
PiControl’s DCS/PLC-based advanced process control (APC) approach will provide significant cost savings, fast commissioning and project completion and high benefits compared to other APC technologies. The basis for these benefits is based on the following:
- With the DCS/PLC-based approach, the advanced process control (APC) will be robust, compact and self-contained. PiControl’s advanced process control (APC) design approach is faster, cheaper, require less maintenance and will not be black-box like model predictive control (MPC, like DMC/RMPCT) but can be understood and maintained far more easily.
- Nowadays most of the industrial plants use powerful and modern DCS/PLC systems with tremendous process control and advanced process control (APC) functionalities. PiControl technology can wholly be implemented inside any existing DCS/PLC system without a need for an external computer, all the peripherals and adding and configuring OPC. All this takes extra time and effort since the configuration of the computer from both systems and applications sides are involved.
- 75 % of industrial processes are sequential with a diagonal control matrix (Figure 1), making it very suitable for DCS/PLC-based advanced process control (APC) without the need for a full-blown model predictive control (MPC, like DMC or RMPCT) or any other advanced process control (APC) technology. The feedback corrective action possible by mathematically optimized DCS tuning parameters will provide crisp, stable and tight control action outperforming model predictive controllers (MPCs, like DMC and RMPCT). PiControl has demonstrated success with DCS-based advanced process control (APC) and has several times outperformed model predictive controllers (MPCs) in the past at other sites.
- PiControl DCS/PLC-based advanced process control (APC) approach can easily handle with nonlinearities, valve or sensor problems, grades transitions, rapidly changing capacities and other typical plant issues.
- During the DCS/PLC-based advanced process control project execution all base-level PID tuning will be performed using closed-loop ultra-short duration data without step tests (Figure 2).
- All designed and implemented advanced process control (APC) logic inside the existing DCS/PLC will be optimized and mathematically calculated using PiControl’s PITOPS. This technology will be provided to the end user for later maintenance.
- Online control quality monitoring of all PID and advanced process control (APC) tags inside the DCS/PLC will be continuously performed by using PiControl’s APROMON software.
- Advanced process control (APC) being all inside the DCS/PLC can be easily supported and modified by a compact team of local and remote engineers. Data analysis for support and improvements can be conducted remotely very efficiently followed by changes on site.
- After and during project execution modern advanced process control training will be provided to end user engineers.
Figure 1 - DCS-PLC-based Advanced Process Control (APC)
Figure 2 - Typical Diagonal APC Control Matrix
Figure 3 - Completely Closed-Loop Identification Without Step-Tests
Advanced Process Control (APC) Commissioning, Activation and Safety Procedures
PiControl has designed, implemented and started-up numerous advanced process control (APC) projects. Advanced process control (APC) projects of this nature and PID tuning optimization have been done by PiControl at numerous sites all over the world with success and safety. PiControl Solutions LLC will provide a document showing detailed advanced process control (APC) project implementation guidelines, conditioning base-level PID control loops and developing the advanced process control (APC) configuration. The procedures will also include details about safe start-up, setting up safety clamps and other guidelines to ensure success, safety and the achievement of the advanced process control (APC) goals and objectives. PiControl will provide complete and simple switching and activation logic with additional advanced process control (APC) screen which will be used to change over between advanced process control (APC) and DCS (existing) just to bring back to normal production.
APC Project Benefits
The goal of PiControl well-designed DCS/PLC-based advanced process control (APC) strategy in consistently operating the unit close to the maximum possible profit day in and day out, safely and reliably. The following criteria can quantify the benefits associated with PiControl DCS/PLC-based advanced process control (APC) approach:
- Production increase:Typically, PiControl expects to see a minimum 2 – 4 % (in some cases even 10 %) improvement in the plant’s operating efficiency production or utility reduction and a 30 – 50 % or more reduction in oscillation amplitudes due to optimized and advanced process control (APC). The oscillation reduction will enable smoother but faster running of the plant with increased stability in all control loops.
- Energy savings:Energy savings from our advanced process control (APC) implementation have been reported to be in the range of 3 – 15 % depending on the process and current operations. Most of the time, utility management is a complex control issue that spans across the site and at times also affects the electric grid. These system applications can be designed to achieve benefits by reducing utility costs up to 60 % the system also can be used to optimize energy production, such as boiler loads, gas turbines, or other.
- Quality improvements:It’s important to reduce variability in the final product quality. Some products are sold at a value that depends on the quality variability of the batch produced. Many companies report a reduction in standard deviation of product qualities of up to 50 % using our advanced process control (APC).
- Yield improvement:Many organizations experience a yield improvement of 2 % through our advanced process control (APC) deployments, typically achieved by optimizing the reactor temperature and/or the ratio of feed to the catalyst or the separation portion. In separation processes, such as distillation columns, maintaining the specifications by our advanced process control (APC) on the final product can increase the yield of the desired product by increasing impurities up to the contracted specifications.
- Grade transition time optimization:During different processes, the production wheel cannot be optimized to market needs, as difficult and time-consuming transitions may be rejected by operations resulting in low-value products produced during these transitions. Through our advanced process control (APC) system, it is possible to “bust the production wheel” and produce grades when they are in demand while minimizing the time when the low-value transition products are produced. It’s common to achieve 20 – 50 % reduction in grade transition time using the appropriate strategy.
- Recycle ratios optimization:Units that can be recycled qualify to collaborate with our advanced process control (APC) system. The good strategy allows for optimizing the feed-to-recycle ratio to maximize throughput and/or maintain quality at specifications and/or to satisfy equipment constraints.
- Emissions control improvement:The implementation of our advanced process control (APC) can help control environmental constraints. By using this process, the emission equipment (such as furnaces and boilers) is possible to operate closer to the emissions limits without violating them. Using our advanced process control (APC) strategy also helps to decrease energy usage and minimize costs to meet NOX, SOX and COX emissions constraints.
- Exploiting ambient temperature effects:our advanced process control (APC) system has proven to exploit the benefits associated with ambient conditions. Ambient temperature has an effect on compressor performance, condensation capacity, gas turbine operation, cooling water temperature, refrigeration capability, gas volumes, and many more process-related conditions. Therefore, units that are affected by ambient conditions can benefit from our advanced process control (APC) applications as they can anticipate these changes and adjust process parameters accordingly.
- Disturbance effect reduction:Without our advanced process control (APC), disturbances arising from upstream or downstream will affect process units and reduce margins. With our advanced process control (APC) technology, units will constantly react to the disturbance optimally.
Before you initiate expensive projects using expensive consulting services and costly multivariable or model-predictive software, first contact PiControl Solutions for amazing low-priced solutions at less than one-tenth the cost while delivering the fullest benefits potential. PI Control Company will send you design strategies, ideas and then assist you remotely with the easy but powerful process control software tools.