Industrial facilities are becoming more aware of the annual energy consumption within their plant and are looking for ways to bring that annual cost down. Many are investing in energy management teams, conducting energy audits, and seeking ways to increase efficiency within their processes with smart heat tracing controls. An example of this is a shift over to using LED lighting for industrial facilities. LED lights are energy efficient that also meet safety guidelines within the facilities.
Let’s explore electrical heat tracing systems and see where control and monitoring can help an industrial facility to be more energy efficient.
An electric heat tracing system maintains the temperature of non-flowing fluids by replacing the heat loss through thermal insulation on pipes, vessels, and associated equipment. The common applications for heat tracing are freeze protection and process temperature maintenance.
Now let’s review the typical control methods and see which is the most efficient way to save energy.
Self-Regulating Control/ No Control
In the case of self-regulating control (sometimes referred to as no control), the self-regulating heating cable is tied to a power connection kit and is energized through a GFI breaker in a power distribution panel. The circuit breaker is turned on at the start of the fall and through the winter months the SR heating cable does its job.
It is very common for most pipe freeze applications to use the no control method and let the heating cable run at 100% power output. The inherent nature of its self-regulating technology will adjust the power output based on the ambient temperature. However, the system never turns off completely when the GFI breaker is on. If maintenance personnel forget to turn off the breaker after the winter season or even if no heating is required during the winter season, energy is consumed year-round.
Ambient Thermostat Control
Ambient sensing control is the next step up from no control, where a thermostat uses a sensor to measure the ambient air temperature, preventing the need to worry about turning on/off circuit breakers. A thermostat or controller with a programmable setpoint is used where the circuit is turned on when ambient temperatures are below this setpoint and turned off when ambient temperatures are above. It’s a simple cost-effective setup, however it’s limited to freeze protection applications. Additionally, the maintain temperature varies with the ambient conditions, and the circuit remains on 100% of the time as long as the ambient air temperature is lower than the setpoint value. This means the circuit could still be energized even when it is not needed. For example, if your setpoint is 40F, and the ambient air temperature is 39F, the circuit remains energized 100% until the ambient air warms above the 40F setpoint value.
Smart, Advanced Control
Using smart controls that can provide advanced features to help maintain your heat tracing is the best way to conserve energy. Most smart controllers have more options to control a heat tracing circuit than a simple thermostat, such as on/off, always on, always off. An advanced controller such as the nVent RAYCHEM Elexant 4010i has a control mode called Proportional Ambient Sensing Control (PASC). This controller can proportionally energize the power to the heating cable based on the ambient temperature. The Elexant 4010i accomplishes this by adjusting the duty cycle to the heating cable, rapidly cycling power on and off to ensure that only the right amount of heat is produced based on the ambient temperature. This way it’s not energized 100% of the time, reducing the overall energy consumption of that system. The savings opportunities can be significant.
Utilizing smart advanced controls are the best option to manage your heat tracing system. It not only helps reduce energy consumption but can also be your eyes and ears to efficiently run your process including:
- Centralize operations and alarm reporting
- Improve process control to improve yields
- Provide data for trend analysis and predictive maintenance
- Increase system reliability and reduced downtime
- Reduce maintenance costs with an autocycle feature that ensures the EHT cable installation is functioning as designed, year round
If you would like to learn more about how smart controls can help save energy, download our case study today.