Pumps & Systems, February 2008
The second article of this three-part series on "Dematerializing the Process" explores how future industrial process plants will address rising operating costs plus energy and environmental concerns. Click here to read part one and part three.
Here's just a sampling of industrial market headlines: Experienced human capital is scarce. Raw material costs are escalating. Energy and the environment are becoming constraints on economic growth. Information technology is the primary economic driver. The process plant of tomorrow is minimally staffed. Manufacturing flexibility is required to customize products for rapidly changing market demands. Manufacturing efficiency is the key to sustainability. Consolidation, globalization and information integration have spawned an array of new and innovative management, sales and manufacturing strategies.
The past may be prologue to the future, but the time between the two seems increasingly short. In the past, labor, capital and raw materials were considered the underpinnings of wealth creation. Today, real-time process knowledge and innovative management strategies have become far more important for creating value, as evident in the headlines above. Accordingly, the time for systemic change is now. . . the opportunity to reinvent industrial manufacturing and the products and services that surround it have never been greater since the beginning of the industrial revolution.
The ubiquitous use of information technology-through sensors and embedded chips in process equipment-increasingly offers not only process data but also real-time asset information that is needed for an integrated view of the production process. Coupled with management practices for equipment selection based on extensive use of life cycle cost analysis, plant owners and associated stakeholders now have the information tools necessary to make decisions that lead to flexible and sustainable production processes. The direct link between expanding information technology utilization and economic results is clear. These collective changes constitute "smart" manufacturing.
The emergence of intelligent motor systems, including "smart" pumps, has also opened the door for industrial suppliers to offer new and innovative product and service offerings that were not feasible in the past. Historically, process plant design has been based on selecting the equipment required to meet production target while achieving the basic goals of safety, operability and profitability. In the future, "smart" plant design will meet these basic goals while achieving the lowest life cycle cost for the capital employed.
In order to build a smart plant, you must design smart sub-systems that report on equipment health and efficiency. Real-time information allows operators to diagnose problems to keep the machine running at maximum performance. It is no longer acceptable to design plants that work-they must work efficiently to achieve the maximum return on capital employed.
Efficient Systems of the Future
A highly efficient pumping system is not merely a system with an energy efficient motor. Improving total system efficiency, not just one component, is the key to maximizing cost savings. The following elements are involved in the overall energy flow of a pumping system. Each element, or interface, adds inefficiency. The overall pump system efficiency is the product of the efficiency of each of the components. Note that the pump is just one of these elements:
- Electric utility feeder (higher voltages and power factors, plus wire resistance, reduce these losses)
- Transformer
- Motor breaker / starter
- Adjustable speed drive (offers extensive system data from which to infer system performance)
- Motor (available in various efficiency ratings and, in some cases, with embedded intelligence)
- Coupling
- Pump (provides energy transfer to the pumped liquid)
- Fluid system (including valves, piping and fittings which all add to the friction loss)
- Ultimate fluid process or transfer objective (rate of flow with required head)
Using financial measures to justify equipment selection is also becoming paramount. This takes the guesswork out of previous assumptions about equipment design. You will know what the life cycle costs are in advance. . . no more excuses for fostering an inefficient design. Today, life cycle cost must be part of the justification, not simply desirable, in order to make sound long-term decisions. Once the system is installed, the embedded intelligence will provide real-time condition monitoring of equipment performance to validate efficient operation, quantify the savings and signal when the equipment needs maintenance. This "intelligence" is the cornerstone of "smart" manufacturing.
For new pump system projects, the design should consider all of the elements that constitute the system. Prior studies have shown that, due to product and transmission inefficiencies, only 5 percent of the fuel used to generate electricity is actually converted to useful work in the form of moving fluid through the process pipe. By optimizing the "system," through selecting the best design and sizing the components to support operating efficiencies, an estimated 20 percent of the fuel used to generate electricity can be converted to useful work.
Opportunities for Efficiency
The following performance improvement opportunities should be considered:
- Eliminate unnecessary flow uses
- Assess pumping system suitability for current application
- Reduce pump speed, trim impeller diameter or install appropriate speed control devices
- Consider alternative pump configurations
- Improve operations and maintenance practices
- Improve piping configuration
As mentioned in the first article in this series, Texas Instruments (TI) set a goal to reduce building costs by 30 percent over previous fabrication designs or the new facility would have to be built oversees. Employing variable speed control, rather than fixed-speed pumps that run continuously, allowed the vacuum pumps to operate at their best efficiency point-regardless of flow rate-and idle when flow was not required. Variable speed operation allowed the motor, pump and pipe components to be downsized for capital cost savings. Furthermore, these changes saved 300 tons of chiller capacity and 7 percent of the plant's total electricity.
The utilization of variable frequency drives provides real-time information that is used to infer performance-including kilowatt hour consumption to quantify the savings-and validate the benefits derived from design changes. While this is a significant savings for the TI facility, just consider that many industrial plants have hundreds of process pumps employed.
Collectively, the use of more efficient pump and piping designs, including wider application of variable speed pumping, offers the potential for major reduction in initial capital costs in addition to major energy savings. Clearly, rethinking the process and taking a methodical, analytical, life cycle cost-based approach to designing pumping systems has the potential for facility capital costs savings of 5 percent or more, with total operating costs savings of 20 percent or more. These levels of savings are possible on new "smart" plant designs as well as major retrofit and modernization projects.
Trimming impellers, installing a variable frequency drive, choosing a pump better matched to the system and improving operating and control procedures will provide significant cost reductions. Installing composite wear rings, which will reduce wearing ring clearances, can also improve pump efficiency. Pumps may be reconditioned to recover lost efficiency. If it has sufficient capacity, operate one pump-instead of two in parallel. These are just some of the approaches that can be implemented.
It is important to conduct detailed system cost analyses, including the time the pump spends at various operating conditions and all component efficiencies, to achieve realistic cost savings projections. The demand for pump system assessment services that are focused on improving energy efficiency, reliability and process control are growing. This is part of an overall trend toward outsourcing plant life cycle services. In process industries, the compound annual growth rates for life cycle services far exceeds growth rates for traditional process equipment.
While these types of services are often seen as more difficult to manage, since they may deal with multiple parameters and complex issues, they constitute a new market opportunity that is critical to creating sustainable process designs. The importance of utilizing intelligent equipment and process optimization services for all stakeholders can't be over-stressed as we move into the immediate future.
Next month we'll take a look at ways to change traditional industry ways of thinking in order to help usher in the plant of the future.