When some people think about heating potatoes and onions, they may be thinking about stew. But a fire at the Alsum Produce warehouse in Friesland, Wis., destroyed not only much of the stored stew ingredients, it also destroyed much of Alsum’s refrigeration equipment. Farsighted management at the company looked at this challenge as an opportunity for expansion and improvement.
Owners and management evaluated the situation and decided that this would be the opportune time to both expand operations and upgrade compressor controls for their refrigeration units. Actually, “control system” was almost a euphemism, according to Josh Vander Galien, vice president of operations and lead programmer for Advanced Energy Controls (AEC), a systems integrator specializing in refrigeration control, based in Randolf, Wis. “Their existing control system was just a thermostat on the wall,” says Vander Galien. The company had 14 refrigeration compressors at the old facility with individual thermostat controls.
“In fact, Alsum doubled its refrigeration operations within the facility,” says Vander Galien. “It was going to cost a lot of money to deploy separate control systems for this (now) more dispersed equipment. To save money, we designed a centralized control system with a rack architecture and distributed input/output (I/O) devices at the individual refrigeration units. We brought the compressors together in two racks. A rack is a bank of refrigeration compressors within one engine room. Within the rack, you can start and stop different compressors by size to get only the amount of compressor power that you want. For example, on this project, we can bring total horsepower (hp) down to where we can run 100 hp rather than the 250 they were running. We used an Opto 22 Snap Ultimate I/O system to control the evaporators and compressors.”
The system works by first tapping directly into Alsum’s main electric utility meter. These meters send a periodic pulse that provides the instantaneous electric demand in kilowatts (kW). The control system monitors this demand to determine the facility’s peak demand. Electric utilities typically impose an extra charge for exceeding a set peak demand limit. AEC’s system tracks the peak closely and sheds loads by switching off compressor units to assure that the peak is not exceeded. But rather than just shut off the first compressor it comes to, the system evaluates the entire facility and the refrigeration needs at every point. It can then make an intelligent decision on which units to temporarily shut off, producing a win-win situation. The peak demand is not exceeded, yet all refrigeration demands are met.
For example, at Alsum, the system knows when the bagging process is beginning and that it will consume electricity. The system then adjusts all the refrigeration units to assure compliance to the set allowable usage range. When the bagging process ceases operation, then the refrigeration units can be reset.
Proof of the energy savings possible lies in the numbers. Alsum doubled refrigeration units from 14 to 28, yet the electric bill stayed the same as before. In other words, a 50 percent reduction in energy usage was achieved.
Not satisfied with even that savings, Alsum and AEC extended the same concepts to facility lighting, heaters in its diesel-powered delivery trucks (necessary for starting the engines after overnights outside in Wisconsin winters), heat exchange in the potato storage area and battery chargers for forklift trucks.
Energy savings opportunities abound in facilities engineering, especially so in a venue where many people congregate—for instance in a hotel/casino complex. Located in the Renaissance Pointe area of Atlantic City’s Marina District, The Borgata Casino Hotel and Spa is the first new casino/hotel/shopping destination built in Atlantic City in more than a decade. The venue brings a Las Vegas-style concept to the Boardwalk.
The Borgata features more than 2,000 guest rooms, 135,000 square feet of gaming, 11 restaurants, a 35,000-square-foot spa, lounges, bars, shopping and entertainment facilities, and 70,000 square feet of conference space. Not surprisingly, employee and guest comfort is key to the success of this new facility. That comfort starts with the fundamentals: hot and cold water. To provide these essential services, The Borgata signed a 20-year contract with Marina Energy, a wholly owned subsidiary of South Jersey Industries. Under the agreement, Marina Energy provides the campus with a full range of heating and cooling services, as well as electricity and natural gas.
Marina Energy uses its brand new Marina Thermal Facility (MTF), a 26,000-square-foot plant, to provide the hot and chilled water needed to heat and cool The Borgata Casino Hotel. The $54 million plant is capable of providing nearly 15,000 gallons of chilled water and 2,600 gallons of heated water per minute, delivering enough hot and chilled water to meet all of The Borgata’s heating, cooling and domestic hot water needs.
Working together
Engineers at Marina Energy envisioned a state-of-the-art facility to maximize energy efficiency. The primary customer, The Borgata, had many automation and control requirements, forcing the engineers to involve several different suppliers with products and project teams that could work well together. The automation system had to interface with third-party systems with easy customization and expansion without requiring development of new human-machine interfaces at each step.
Chosen for the controls portion of the project, Rockwell Automation Inc.’s project team recommended a system with a central point of control, which would loop back to a central control room, even though control would also be distributed throughout the plant. The team integrated ProcessLogix and ControlLogix controller platforms with enough variable frequency drives to control 4,550 hp worth of AC motors at the facility. Key to success was the ability to integrate the flow of information from sensors in the plant to users’ desktops.
Power monitoring equipment and software from Milwaukee-based Rockwell Automation collects and trends data from more than 300 points throughout the plant. Web-based capabilities of the company’s RSEnergyMetrix software provides ready information access to all operators who need it in order to optimize energy consumption and reduce energy costs.
The Borgata casino complex opened on July 2, 2003, a weekend that turned out to be one of the hottest on record. Did the gamblers keep their cool? Frank DiCola, president of West Atlantic City, N.J.-based DCO Energy, the developer for Marina Energy, reports, “The system operates exactly as we thought it would.”
Iberdrola Generación S.A.U. is Spain’s second largest electric utility, serving 16 million customers in Spain, Mexico, and Central and South America. The company has more than 100 years of experience operating hydroelectric, thermal, fossil fuel, nuclear and renewable power-generation facilities with a combined capacity of more than 22,000 megawatts (MW). Two years ago, it opened a Center for Monitoring, Diagnosis and Simulation (CMDS), a dedicated facility that monitors the real-time performance data transmitted from its power facilities around the world, analyzes and then distributes the data to plant and corporate managers with the goal of reducing maintenance costs and increasing reliability.
The company was using PI, a data historian from OSIsoft, a San Leandro, Calif., supplier of performance management software. But the entire information technology (IT) infrastructure included personal computers with Microsoft Windows 2000, Microsoft Windows NT servers, Cisco network switches and a number of real-time applications. The trick was to extend real-time monitoring from the plants to include the network, as well.
Miguel Chavero, the CMDS IT manager, knew he needed a way to gather the disparate information in one place and monitor it in real time. “In the past, I needed several different tools to monitor the devices, one for each vendor,” Miguel says. “My goal with CMDS was to use one tool to monitor them all.” He chose IT Monitor from WiredCity, an OSIsoft subsidiary in San Leandro, because of its ability to monitor the network in real time, along with its capacity to store large amounts of data. Also, Chavaro explains, “I knew PI and its capabilities. When I saw that IT Monitor was an OSIsoft tool, I knew it was the way to go because we’d had very good experiences with it.”
Installation was a simple process, according to Chavero. “Once you’ve installed one PI server, the rest are easy,” he relates. “Since Iberdrola had PI servers in each of its plants, setting one up in the CMDS was quick and painless. We are using all of the interfaces: simple network management protocol (SNMP) for Cisco devices, Performance Monitor for Windows, Packet Capture, Netflow, Syslog to track the Windows 2000 servers and Ping to measure response times from the power plants.”
Chavero’s primary use for IT Monitor is preventive, since his team’s goal is to keep the infrastructure running 24 hours a day without interruption. A single power plant shutdown can cost the company nearly $600,000. Currently, IT Monitor has helped Iberdrola achieve an infrastructure reliability of 99.5 percent, but Chavero is confident the utility can reach his goal of 99.9 percent. “If our systems are working, our people are working, and that saves money,” he explains. “I would guess IT Monitor is saving us $100,000 a year.”
Homegrown control
Wisconsin Public Service Corp. (WPS), located in Rothschild, Wis., is a public utility serving more than 440,000 electricity customers in 11,000 square miles of northeastern Wisconsin and an adjacent portion of Michigan’s Upper Peninsula. The company operates a network of coal-fired, nuclear, hydroelectric, wind and natural gas peaking power plants that provide up to 2,000 MW of electric power. Its innovative approach to automating power generation processes sets it apart from many other utilities.
About two-thirds of the WPS generation capacity is provided by coal-fired plants, and the company has enhanced the efficiency of those plants—while significantly reducing the cost of producing power—by developing its own open-architecture equivalent to the standard distributed control systems (DCSs) that run other utilities’ coal-fired plants.
Plant management of the company’s three coal-fired units at the Weston complex has deployed personal computers (PCs), programmable logic controllers (PLCs) and software packages to create their own DCS system at far less cost for both initial system implementation, and life cycle cost of ownership and maintenance. The control systems have enabled the integrated control of three plants that were built over several decades. They also have given plant management and operators the ability to fine-tune operations more efficiently, because multiple systems now share a common historian database for all three coal-fired plants, as well as two peaking units.
In the mid-1990s, the original control systems were creaking with age, and WPS management realized they needed to be replaced, not just to facilitate plant operation, but also to make the units run more efficiently. If the company could produce power from the same equipment at less cost, then the building of additional generating units could be stretched out over time.
WPS decided to replace the original pneumatic control systems with PLCs to control equipment functions, and to use PCs running human-machine interface (HMI) software to enhance operator interaction with the units. A network of Modicon PLCs supplied by Paris-based Schneider Electric was installed for equipment control, while PCs running InTouch HMI software from Wonderware, a Lake Forest, Calif.-based unit of Invensys Process Management, were deployed as operator interfaces to the PLC controls. To emulate the functionality of a typical DCS system, WPS installed the ControlPlus distributed control software developed by Standard Automation, a Texas-based Wonderware authorized distributor. The complete set of software products was provided through GS Systems, Wonderware’s distributor based in New Berlin, Wis.
On the money
“This solution was exactly what we needed because it gave us all the functionality of a standard DCS system, but it was much less expensive to implement and it allowed us to integrate under one control system all the equipment that we had installed from various manufacturers over a 40-year period,” says Daniel Snyder, WPS instrument and control team leader. “We didn’t have to worry about whether our steam generators came from Babcock & Wilcox or Combustion Engineering, or whether our turbine generators came from Allis Chalmers or GE. All of our coal-fired processes are 100 percent under automatic control.”
Snyder observes that production requirements have become so complex over the last decade that there is “no way” that human operators could coordinate all of the critical steps involved. Instead, “the historian maintains complete records on every step in the process,” he says, “so we have an audit trail on everything that’s done by the control system. The trending software allows both operators and management to quickly and easily view and analyze any parts of the process, and we often can find potential problems before they even occur.”
Has the approach led to bottom-line improvements? You bet, Snyder responds. “This has made us far more efficient,” he says. “In effect, we can fine tune the process as it’s running.”
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