The first part of this report dealt with pumps, increasing demands for energy efficiency and decentralized intelligence. In the second part, learn more about valves and their role in automation as well as new business models for buying compressed air and how to design your system for maximum efficiency.
Controls and Valves 4.0: when will systems go wireless?
Besides process control systems and sensors, actuators play an important role in automation and process engineering. In its 2014 sensor trends report, AMA reports that direct sensor – actuator connectivity is on the increase.
Controls and valves can adjust material flows to regulate process parameters such as pressure, temperature, flow rates and fill level. “Intelligent” control valves with add-on modules are available which not only perform the control function but also automatically detect the need for maintenance or repair before a fault occurs. In the final analysis, these smart controls and valves improve production reliability, increase cost efficiency and help protect the environment. Suppliers expect that actuators will be used to a greater extent in control loops in the future. This could ultimately lead to wireless control. The actuator technology already exists.
Wireless sensing is a promising branch of sensor technology. Wireless measurement data transfer is not really new, but its potential in the industry has only recently been recognized. The technology looks very attractive but there are hurdles to overcome such as real time capability and reliability, and they are slowing the pace of introduction.
Actuator systems continue to rely on the traditional technologies: electric, hydraulic, pneumatic and electrohydraulic. But even here, more and more control and diagnostic functionality is being built into the drives. This is another application for distributed intelligence.
Electric valve actuators have the advantage that they can easily be connected even over large distances and they are relatively lightweight. Pneumatic systems have short actuation times and withstand long duty cycle ON times. However the actuator is large and heavy. Hydraulic systems are maintenance intensive, but a smaller actuator generates more force compared to a pneumatic system.
One supplier is currently talking about a paradigm shift in single-use technology. Manual systems can be replaced with devices suitable for automation and control which support fault-free operation and continuous documentation by the monitoring system. The valve body and the actuator on the new product are connected using a special locking mechanism. Following use, the valve body is removed and the actuator remains in the system for repeated use. If necessary, the valve actuator can send feedback to the monitoring system, adding the final element needed to fully monitor the control loop. The manufacturer claims that this approach facilitates process reproducibility, documentation and validation in pharmaceutical production.
Compressors 4.0: more efficient generation of compressed air
A big campaign took place in Germany a number of years ago to increase the efficiency of compressed air generation, and it served as a blueprint for similar campaigns by the German Energy Agency (dena). A study by Markus P. Rößler (TU Darmstadt, 2014) indicates that more opportunities exist to increase efficiency.
Between 2002 and 2012, companies were able to increase energy efficiency in the total compressed air system by an average 5% – 10%. An increase >10% would be technically possible but in most cases would be prohibitively expensive. The increased use of high-level control systems, drive motors with frequency control, gearless drives and permanent magnet motors instead of asynchronous motors could help boost efficiency.
Besides the actual generation of compressed air, the system context is also important. Users are making a greater effort to recover heat even on older compressors. They are also looking at optimization of auxiliary equipment such as dryers. From the overall system perspective, minimizing leakage yields the best cost/benefit ratio. Setting the pressure to the lowest possible level for the application can also boost efficiency. More and more companies are embracing operational energy management.
No radical change in the compressed air generation process is expected in the next ten years. The main emphasis will be on overall system optimization. The required use of IE 3-compliant electric motors will lead to further energy efficiency gains. On systems with variable compressed air consumption, users are looking for durable actuators which react quickly and continue to work reliably even in applications with frequent start-stop operation. Variable-speed compressors and higher-level controllers can reduce energy costs by substantial amounts. Energy consumption can be reduced by as much as 30% – 40%.
In the future, demand will continue to increase for oil-free compressed air and not just in the medical equipment, pharmaceutical and food industries. Greater environmental awareness will extend the horizon of oil-free technology to standard applications as well.
In the era of Big Data and Industry 4.0, systems and applications will become more and more intelligent and they will be integrated into complex industrial infrastructure, claims a leading manufacturer. One-stop shopping is an attractive option for a user base which increasingly prefers complete solutions.
Under the compressed air contracting model, users purchase compressed air at a fixed price rather than generating it with their own equipment. The industry is convinced that this business offers considerable potential.
TOP – the gateway to a systems approach
Experienced systems designers are normally able to combine functionality and efficiency. Inexperienced designers are unlikely to be able to do that. With reference to eco-friendly design, you could make the following provocative assertion: It is very possible to take a number of highly-efficient, well-designed machines and put them together in a way which creates a poorly designed system that is very inefficient. That at any rate is the opinion of Dr. Ulf Lorenz, Dr. Gerhard Ludwig and Prof. Peter Pelz at TU Darmstadt who are the originators of the TOR concept. So what is it all about?
New design strategies are needed to save significant amounts of energy on fluid systems which consume energy. A product approach or extended product approach must give way to a system approach. Like chess players, designers have to simulate and analyze various scenarios until they have found the system topology which performs a process function with minimal energy consumption. Mathematicians and engineers at TU Darmstadt are working together to find solutions, and the TOR virtual design software is being developed by the Fluid Systems Technology Department. The term TOR (Technical Operational Research) refers to both the virtual design software and the new research body. The goal is to provide a decision-making aid to support system design and operation and to assess energy efficiency.
Summary: Digital networking on fluid flow systems based on distributed intelligence at the subsystem level creates a straightforward pathway from the product approach to the systems approach. The availability of relevant information on the process and the set point/actual operating parameters of pumps, compressors, controls and valves supports maximum utilization of input energy, predictive repair and maintenance and higher system availability.
Extensive use is being made of the capabilities offered by today’s smartphones, primarily to query and modify set point/actual values. It will probably not be long before wearables like Google Glass become part of the toolkit. Maintenance engineers will be able to read all of the work procedures on mobile displays which are located right in front of their eyes. The instructions may be presented in a form similar to the way players received messages from their avatar in adventure games.