Advanced Process Control (APC) is an effective lever for improving product quality and increasing productivity, profitability and the environmental sustainability of production plants in the process industry.
Established control concepts in the process industry today still rely predominantly on PID controllers. When automation reaches its limits, it is necessary to resort to manual intervention by the plant operator. However, using APC methods that can mathematically describe even complicated relationships of process parameters, considerably better results can often be achieved.
APC enables unwanted fluctuations of process variables to be reduced and thus enables setpoint values to maintained closer to critical secondary conditions (constraint pushing), without violating these limits. While this reduces the work for the operating personnel, it also enables throughput and product quality to be improved and a noticeable reduction in the use of raw materials and energy consumption.
In the control libraries of SIMATIC PCS 7 the following function blocks and templates are already available for higher-level control functions at no extra cost:
- Gain scheduling
- Override control
- Lead-lag/feed-forward control
- PID controller optimization (PCS 7 PID Tuning)
- Control performance monitoring
- Smith Predictor
- Model-based predictive multi-variable control
Further high-quality closed-loop control functions can be seamless integrated as add-on products into the SIMATIC PCS 7 process control system (for details, see Chapter "Advanced Process Control"):
- FuzzyControl++
- Soft sensors (INCA Sensor)
- Model-predictive multi-variable controller (INCA MPC)
- Extended PID controller optimization (INCA PID Tuner)
- Adaptive controller (ADCO)
Supplementary to this, Siemens offers extensive services for implementing APC solutions with the "Premium Service Advanced Process Control"
- Technical consultation
- Experimental examinations
- Implementation of APC functions
These services are particularly aimed at customers from the pharmaceutical and chemical industry as well as the food and beverages industry.
The services of the Premium Service "Advanced Process Control" are mainly suitable for:
- Production processes in the chemical and pharmaceutical industry and in the food and beverage industry
- Optimization of the automation systems of process engineering processes
- Evaluation and migration of existing automation systems systems and configuration of new plants
They are of particular advantage for processes with:
- Difficult control routes, e.g. with long reaction times
- Unpredictable disturbance of process variables
- Reciprocal action between different process variables
- Frequent load changes and transitions between the work points
- Unfavorable basic automation, e.g. poorly adjusted PI/PID controllers
- Consultation, •engineering and implementation from a single source
- Control system-integrated implementation with standard function blocks
- Optimization of the operation of process engineering processes:
Productivity and economy
- Increased throughput (typically 1 to 5 %)
- Minimization of energy use (typically 3 to 10 %)
- Reduction of down times
- Increased productivity (typically 2 to 10 %)
- Shorter throughput times
Quality
- Improved reproducibility of plant operating methods
- Minimizing the fluctuation of quality parameters
- Reducing the expenditure on analysis
Flexibility and availability
- Greater tolerance to fluctuations in raw materials
- Increased robustness and reduced sensitivity to interference
- Extension of the plant life
Ease of operation
- Reduced workload for personnel
- More convenient operation
- Change of operators not quality-relevant
Environmental protection
- Minimization of waste material
- Reduction of emissions
- Less waste water
The Premium Service Advanced Process Control is split into three complementary modules that can be ordered individually:
Module 1:
Determination of the APC optimization potential through analysis by experts
- One-day Workshop for analyzing the customer's production processes and process automation with the aim or determining process variables for the optimization by means of conventional and superior closed-loop control methods
- Participants: Siemens experts and representatives of the client with profound knowledge of the process and its automation
- Prior agreement of workshop details between client and contractor, e.g. on the basis of a target-oriented specification
- Where necessary, the client provides the required basic material for the workshop, e.g. flowcharts and descriptions of the production process
- Typical workshop content:
- Examination of the process engineering, focusing on economically relevant process variables that can be optimized
- Analysis of the basic automation
- Consideration of conventional closed-loop control procedures and potential APC methods
- Determining the customer benefit
- Result: Workshop documentation with evaluation of the APC potential and specific recommendations for further actions
Module 2:
Preparation of a feasibility study
- Approx. one week feasibility study for verification and detailing of the optimization potential identified in Module 1:
- Substantiated analysis of the identified optimization candidates
- Preparation of optimization options
- Participants: Siemens experts and representatives of the client
- Prerequisites:
- Basic automation, closed-loop control concept and instrumentation comply with the current state of the art
- Detailed information is available about the processes considered and their method of operation
- Access to the customer's process control system is possible, e.g. for recoding data of relevant process variables during operation
- Inclusive services:
- Preparation of process expertise, e.g. by tracking the reactions to targeted minimal interventions in the process or by exchanging experiences with the plant operators
- Examination of the current closed-loop control concept for optimization potential
- Presentation of suggestions for actual optimization measures
- Assessment of the suggested optimization measures
- Cost estimation of the implementation with an accuracy of ±25 %
- Basic deadlines for implementation of measures
- Result: Documentation of the feasibility study with qualitative and financial evaluation of possible optimization measures and specific recommendations for further actions
Module 3:
Implementation of the prepared feasibility study
- Implementation of the optimization measures recommended in Module 2
- Content is the subject of an individual agreement between client and contractor
- Typical service content:
- Plant tests and model creation
- APC implementation in the process control system
- Commissioning
- Training
- Involvement in the validation in a field regulated by GMP (good manufacturing practice)
- Basis for the individual agreement is a project-specific quotation provided by Siemens as the contractor
- Inquiries for production of a quotation should be directed to the address specified under "Further information"
Note:
The modules of the Premium Service "Advance Process Control" do not include any traveling expenses. Traveling expenses from the Hoechst Industrial Estate, Frankfurt am Main, Germany, will be invoiced separately.
Siemens AG
Industry Sector
Industry Automation Division
Industrial Automation Systems
Industriepark Höchst, Gebäude B598
65926 Frankfurt
Tel.: +49 69 797 84500
E-mail: team-ec.industry@siemens.com
You can find additional information on the Internet at:
http://www.siemens.de/ec
