Cooling Controls

Process cooling systems are mandatory components of the production infrastructure in many plants. System efficiency is second only to operational performance (i.e. meeting the process requirements) in the design and operation of these systems, and many companies go to great lengths to attain system efficiency.  Many times, unfortunately, the actual system performance is well below the hoped for efficiency target.

This article will discuss the instrumentation typically found in cooling systems and other plant utility systems, what other instruments and gauges should be used, how the instrumentation should be used, and good maintenance practices for instrumentation.
The need to pay close attention to the university’s central chiller plant has always been a priority given the energy required to power the chillers, said Michael Bolien, Manager of Central Plant Operations, University of Tulsa. At TU, seven water-cooled chillers provide 7,000 tons of cooling capacity to all university facilities. “Over the past five years, TU has had a 17% increase in cooling load, based on the square footage of new buildings. Because our central chiller plant is our biggest energy user, optimizing its operations is our first line of defense,” said Bolien.
In recent years, the HVAC industry has enlarged its vision from focusing on equipment efficiency measured in terms of ratings points at specific conditions to include a whole building perspective that uses models of year-long, real-world conditions. Accordingly, energy standards have adopted new rating methods to evaluate equipment efficiency during part-load operation. In Part 1 of this two-part article series we examined how these standards are evolving.
Chillers are an essential component in many building Heating, Ventilation and Air Conditioning (HVAC) systems. They provide cooling to the building by working in tandem with pumps and cooling towers in a water-cooled chiller plant. Because of the chiller’s complexity and its role in cooling facilities, it is arguably the most important piece of equipment to maintain.
The chilled water is generated in the central plant and then transported through a piping network to cooling coils (air handlers), or to point of end-use in processes. Facility directors and energy managers are always chasing multiple goals - satisfying all the customers, maintaining a high-level of reliability and minimizing energy spends with varying demand and weather. Therefore, many modern plants employ a good chiller optimization package such as Hudson Technologies’ SMARTenergy OPS® in conjunction with Building Automation Systems (BAS) to optimize the chiller plants.
Manufacturers are under continual pressure to control costs without affecting operations or worker comfort and safety. Because energy ranks as one of the largest operating expenses, improving energy efficiency of mechanical cooling systems is one of the best ways to reduce operating costs. In a typical water-cooled chiller plant, the chiller itself accounts for most of the energy consumption. That’s why improving chiller efficiency is critical to controlling operating costs.
Intelligent process cooling describes an approach to cooling in beverage production and packaging that moves beyond evaporative cooling towers and the use of traditional central chiller systems that rely on ammonia as a refrigerant. Unlike traditional methods, it intelligently matches process cooling systems to individual cooling loads without an evaporative process or the use of ammonia to gain verifiably better results in energy efficiency, water use, and safety.
Chrysler’s Technology Center (CTC), located in Auburn Hills, MI, is home to some fourteen thousand employees responsible for keeping the automotive giant in motion. Completed in 1991, the complex is essentially a small city, encompassing 5.3 million square feet situated on over 500 acres. In addition to corporate offices, the facility houses a full laboratory level of various wind tunnels with thermal testing capabilities, a 1.8-mile evaluation road, a noise/vibration facility, an electromagnetic compatibility center, an environmental test center (able to create rain, snow and extreme temperatures), and a pilot production plant.
Pepco Energy Services’ (PES) Midtown Thermal Control Center (MTCC) in Atlantic City, New Jersey, sells chilled water and steam to multiple Atlantic City casinos, Boardwalk Hall and Pier Shops. PES is also responsible for stand-alone remote heating and cooling plants for the Atlantic City’s major casino’s as well as the Atlantic City Convention Center including its 2.4 Mw solar array.
Visitors to the Frigel booth W7991 at NPE 2015 will get a close look at the world’s most efficient and sustainable plastics process cooling system – now more adaptable to meet plastics processors’ specific needs. Among the latest Frigel innovations on display will be the new 3PR Intelligent Control System, which provides processors with even easier and more precise control over their Frigel cooling systems. Featuring a unique 7", full-color touch screen interface, 3PR allows processors to achieve better closed-loop process cooling system accuracy with more data points at their fingertips.