Have you ever woken in the middle of the night in a cold sweat wondering if your plant is using more energy than it should, putting you at a disadvantage as compared to your competition? Even if your energy monitoring or energy management system is in place you may not have the required insight to improve your performance and keep you competitive.
But lost sleep isn’t necessary. Simple but effective integration of readily available data in the plant can provide a whole new level of actionable information. Here’s what you need to know.
Take Control of Energy Efficiency
To get needed insight you would need to have the ability to record or log data across multiple systems, including production data. As the old adage goes, you can’t manage what you don’t measure. It follows that if you are able to measure something with a greater level of precision and correlate it to the bottom line with production data, you will be able to manage it even better. Overall Equipment Effectiveness (OEE) measures the percentage of manufacturing time that is truly productive.
The same should be measured as it relates to energy so that the overall energy used to make each widget is as low as it can be. Most will already be familiar with the concept of Key Performance Indicators (KPIs) and how they can inform system optimization. By adding the factor of production data and establishing energy intensity KPIs, you can take your energy optimization to the next level, stay on top of costly or dangerous miscalibrations, and truly take control of your energy efficiency.
Monitoring energy usage of systems such as cooling towers can take energy optimization to the next level.
What KPIs Should be Tracked?
KPIs are important tools for optimizing any system, and chillers and cooling system are no exception.
We recommend placing sensors at key points in a chiller system for monitoring energy usage in kW including the cooler tower pump, chiller, cooling tower fan, and AHU fan, as well as water return temperatures, chilled water supply temperature, and chilled water flow.
To take a more precise look at your system and add value to your KPIs, adding monitoring for chilled water supply temperature, chilled water flow and chilled water return temperature may be of much greater value then monitoring the kW of the chiller itself. Location matters as well. Many times, plants make the mistake of installing power meters on panels around the plant but if the area covers more than one production line or department, the value of this measurement is limited. Tracking should be system-based and not area-based.
Include KPI Production Data
Any system within your plant consuming energy has crucial indicators that should be monitored to ensure efficiency, reliability, and maintainability. You can aggregate the various energy usage KPIs of a given system to realize a system-wide KPI, or taken a step further aggregate each essential system KPI to give you a reading on overall plant energy performance. These system or plant energy performance KPIs are the best indicators of overall energy use and should be carefully monitored across the board to ensure efficiency.
A fully developed system should include KPIs for individual systems as well as the plant. Each energy or water system in the plant has its own KPI, including kW/ton of refrigeration for the ammonia plant and cfm per kW for compressed air, and so on, with more granular KPI’s for components of each system as shown in Figure 1.
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