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Optimizing Plant Energy Management to Increase Efficiency

When it comes to plant energy management, the ability to better monitor combustion air, fuel gas flow and compressed air can help identify losses that over short periods of time can affect profitability. Regardless of the scale of an operation, any improvements in efficiency to purchased fuel and electricity consumption drop directly to a company’s bottom line. The ability to monitor the end-use location of fuel throughout a facility as well as the consumption specifics for individual applications — predominately the boiler — can offer insight to potential areas of improvement. The same is true of electricity consumption. In both instances, reductions can be realized by simply identifying where the energy is being lost.

The ideal instrumentation for monitoring energy usage is cost-effective and provides a strong return on investment. The goal is to realize the benefit in the shortest time frame possible at the most reasonable cost. Thermal dispersion mass flow meters are an optimal choice for both these considerations.

Benefits of Thermal Mass Flow Meters for Energy Management

Thermal mass flow meters are primarily used in air and gas flow measurement applications. The meters consist of a transmitter and probe with temperature sensors (RTDs) located in the pins at the bottom of the probe. The reference sensor measures the process temperature and the other sensor is heated to a specific temperature above the reference. As the flow rate increases, heat gets taken away from the heated sensor. More power is then applied to the heated sensor to maintain the temperature difference. The relationship between power and mass flow rate is established during factory calibration.

There are many benefits to using thermal dispersion mass flow meters in plant energy management applications:

  • Repeatability of ±5% of reading
  • Direct mass flow measurement without the need for pressure or temperature compensation
  • Easy installation
  • No on-site or in-situ calibration
  • Strong signal, high turndown and good sensitivity with low flow rates
  • Accurate measurement under varying pressures

Considerations for Better Plant Energy Management

When looking for ways to improve plant efficiency, there are a few areas where better, more accurate measurement can make a difference. Combustion air flow measurement to a boiler is important to maintain a stoichiometric ratio with the amount of fuel being supplied. Too little air flow can result in incomplete combustion along with additional carbon monoxide or pollutants depending on the fuel being burned. On the other hand, too much air flow can cool the furnace and waste heat out of the stack. The repeatability of the air measurement is essential to obtaining the most efficient air-fuel ratio (AFR).

Measuring fuel gas flow (natural gas or propane) usage to individual combustion sources compared to the output (steam/hot water) can help optimize boiler efficiency and better manage energy consumption. Knowing individual boiler performance may also assist in operating those offering the best efficiency. Lowering fuel consumption is one of the easiest methods to reduce cost and improve profits.

Another key component of energy and facilities management is making compressed air systems more reliable and efficient. Valuable resources are wasted when a leak goes unnoticed or cannot be easily isolated.

By implementing more effective measurement solutions, plants can reduce the inefficiencies that lead to hidden maintenance costs and improve their steam generation. To learn more about level and flow measurement for all aspects of the steam generation cycle, visit