How IIoT Can Improve Chiller System Operations
Innovate or get left behind: consumer smart devices drive demand for smart manufacturing data collection and control.
When most hear the terms “Internet of Things” or “IoT,” they think of readily available gadgets that can remotely control their home’s climate, play their favorite songs or automatically adjust their backyard smoker based on the temperature of the brisket. In essence, IoT is a system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers (UIDs) and that have the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.
These IoT devices have become commonplace and, as such, consumers expect a lot more from technology in all facets of their day. Devices are expected to make our lives easier and anticipate our needs. These changing expectations are forcing manufacturers of consumer products to invest in and adapt to this technology.
Yet, IoT is influencing the manufacturing arena as well. Those accustomed to voice control and seamless automatic operations seek the same types of advantages in the manufacturing plant. This has given rise to the Industrial Internet of Things (IIoT), a network of connected components, often controlled within multiple groups. The connected components communicate and share data that is used to monitor, record and automate processes to improve system operation, serviceability and reliability within a facility. IIoT technology in industry often translates into better operations and reduces service and maintenance costs because it provides continuous web-based access to critical process information.
About three years ago, the full potential of IIoT was revealed to me after striking up a conversation on a flight from Seattle to Raleigh, N.C. My seatmate informed me during pre-takeoff introductions that he worked for Amazon, and his team’s focus was IIoT. As a manufacturer of industrial chiller systems, I was intrigued and then excited when he asked me to imagine walking up to a piece of industrial equipment and asking, “Alexa, when do I need to replace the air filter?”
“The filter was replaced on December 4th. Please inspect and replace within 29 days,” Alexa would respond. “Can I send you a calendar reminder? Would you like to preorder the replacement filter? For installation instructions, please watch this video….”
It was abundantly clear that this industrial fortune-teller had just given me one map that outlined where IIoT was headed. For our company, the path forward was clear. We would increase our investment in this area and find partners to help our team develop and implement this technology into our equipment.
In addition to finding sensors that were able to handle the difficult conditions of industrial chiller systems, engineers had to learn how and where to locate these sensors to protect them. At the same time, they also had to provide access to them for field service technicians to test, calibrate and replace when required.
Early IIoT goals for industrial chiller systems were relatively simple. Customers’ expectations could be exceeded by providing only some of the following services:
- Monitor critical operational data received from equipment via a web-based system.
- Provide alarm and alert notifications via email or text message.
- Record and store enough historical data to help diagnose faults after an event and help prevent it from reoccurring.
- Interconnect with customers’ existing control system.
As chiller system manufacturers began applying IIoT technology into their equipment, several challenges quickly found their way to engineering teams. The big three were:
- Data quality.
Though other hurdles such as monetization and hardware development also needed to be tackled, this article, will focus on the big three.
Challenge 1: Security Issues
Many in the industry took note after an infamous data breach was linked to a mechanical contractor who connected had the HVAC equipment of a major U.S. retailer into it’s the retailer’s internal computer network. This allowed hackers to gain access to the retailer’s network and steal confidential customer data and credit card information.
Following such a wide-reaching and widely reported data breach, companies realized they would need to increase their focus on security strengthen network firewalls to close down and prevent access. Companies implementing IIoT technologies embraced these changes as well.
The increased security helped to prevent hackers’ access to IIoT technologies. However, it created other problems and challenges for the connected IIoT systems. The beefed-up firewalls and updates caused connections to be interrupted and systems to go offline. It generally took a system alarm or an unreported fault before it was realized that the connection was not active. Then once discovered, the equipment had to be reconnected to the network.
IIoT-enabled chiller systems provide access to tools and resources that are accurate, offer ease of access and are delivered within a secure platform.
Challenge 2: Connectivity
Once securely connected, an Ethernet cable connection (Cat 5, 6, 7, etc.) has proven to be the most solid path to link a customer’s network to their industrial chiller system. It can require a substantial investment initially with cabling and connection setup. After installation, however, costs are minimal to maintain the connection.
Another solution is a dedicated cellular connection. The combination of a secure and encrypted transmission path coupled with a dedicated, direct connection (that also eliminates connecting into the customer’s network) is becoming the popular choice. Customers exchange the upfront cabling costs for a monthly cellular connection plan.
For cases in which cabling is not feasible or cellular is not available, other options include WiFi and point-of-site transmitters/repeaters to help connect the equipment to the customers network wirelessly.
Challenge 3: Data Quality
Good data equals Good IIoT. With a solid and secure connection, your IIoT system is only as good as the data collected. You cannot get accurate and reliable data without accurate and reliable sensors. Unfortunately, industrial chiller systems provide a challenging environment for sensors due to:
- High moisture/high condensation.
- Extreme temperatures.
- System vibration.
- Outdoor elements and exposure.
Most early IIoT alarms and faults were caused simply because a sensor failed or the data it was providing was not accurate. System manufacturers can test hundreds of sensors before finding one certifiable to withstand the conditions they are required to serve in.
In addition to finding the right sensors, engineers had to learn how and where to locate these sensors to protect them while also providing access to them for field service technicians to test, calibrate and replace when required.
IIoT Impact on Chiller Systems
With these three challenges addressed, let’s look at how adding IIoT technology is changing the systems being offered and developed.
Industrial chiller systems utilize a network of connected sensors, devices and controls to provide total cooling control that extends through each part of the system, including:
- Compressor control.
- Condenser control.
- Evaporator control.
- Fluid control.
Compressor Control. Of course, IIoT-optimized compressors use data from standard operating sensors (reporting discharge, suction and oil pressures and temperatures). They also allow system designers to modulate the compressor based on numerous additional data points for enhanced capacity control, peak power operating condition management and even deliver overspeed capacity to help serve short-term, high load situations.
IIoT technology is changing the face of industrial chiller systems being offered and developed today.
Compressor manufacturers are offering compressors with factory-embedded sensors to monitor and protect the compressor from operating outside the design operating windows.
Condenser Control. For decades, variable frequency drives (VFDs) have been applied to condenser fans, ramping the fan motors up and down to maintain constant condensing pressure. The ability to modulate the fan speed not only stabilizes the condensing pressure of the system, but it also decreases stress on the condenser coil. Also, with IIoT technology, it can also provide early detection of coil fouling.
Historically, discharge pressure control valves were a necessity to deliver reliable extreme winter operation by decreasing the surface area of the condenser through flooding the condenser surface with liquid refrigerant. Today, these valves are being replaced by IIoT-driven controllers that look at multiple data sets. These controls can modulate flow (air and refrigerant) to provide reliable operation in almost any weather condition. And, they accomplish this by factoring the ambient temperature while monitoring compressor conditions and maintaining control of the system load.
Evaporator Control. Chiller evaporator performance also has been enhanced. The electronic expansion valve (EEV) provides added control of the refrigerant flow while also monitoring and controlling the corresponding chilled fluid flow through the evaporator.
Historically, a partially plugged, or fouled, system strainer would trigger an alarm or result in the system freezing up. IIoT-enabled controls determine that the flow has been restricted and send an alert notifying the customer. But, rather than shutting off the system, the control modulates the EEV down to reduce the flow of refrigerant and enable the system to remain online, at a decreased capacity, until the alert can be cleared and design flow is restored.
Fluid and Pump Control. VFDs on fluid pumps were adopted early into industrial chiller systems. It was easy to prove energy savings by decreasing the pump speed while under low load conditions. IIoT-equipped chiller systems now can also modulate the flow based on anticipated load conditions. This keeps the system operating within optimum design windows, reducing or increasing flow based on utility requirements, load conditions and environmental conditions.
So, it is three years later, and you might be wondering if our equipment today enables a service technician to simply ask “Alexa” to identify the issue and provide the best corrective solution? Well, not exactly, but modern IIoT does provide access to tools and resources that are more accurate, easier to access and delivered within a secure platform. But most importantly, processors today are asking for it, and they are expecting it. PC