Generating electricity in a natural gas power plant is a complex process due to the multiple steps involved with the different types of fluids being used and optimized. Dr. John Olin, Founder of Sierra Instruments, explains how thermal mass flow meters, vortex flow meters, and ultrasonic flow meters can improve the flow energy management in power plant applications in this latest video from Sierra Instruments.
How a Power Plant Works
When most people think of power plants, they immediately jump to an image of hot coals and smokestacks towering in the sky. However, most power plants today are either burning natural gas or in the process of switching to natural gas.
To start the process of creating electricity, power plants bring together air and fuel (natural gas or coal), creating combustion. This creates an exothermic reaction and heat is released. The heat boils water in a boiler creating steam. The steam runs through a turbine, which causes the turbine to spin, thus generating electricity. Voila!
Best Flow Meter Technologies for Flow Energy Management in Power Plant Applications
Now that we know how power plants work, we see that there is gas, liquid, and steam that needs to be measured in order improve the efficiency of energy production and save money on energy waste. With efficient energy production, power plants can also minimize the CO2 going into atmosphere, which contributes to climate change in the form of greenhouse gases. The question becomes which flow meter technology measures each fluid the most effectively.
- Inlet Air and Fuel (Natural Gas) for Combustion – Power plant managers must accurately measure the air and natural gas ratio for efficient combustion in the boilers. Too much natural gas is wasteful and costs money and not enough will not create a flame hot enough to efficiently boil the water in the boilers. Thermal mass flow meters are ideal for combustion applications because mass flow rate, not volumetric, is the quantity of direct interest whenever the molecules of the gas are the control variable in your process. Because thermal mass flow meters count the molecules of gas, they are immune to changes in inlet temperature and pressure. Thermal mass flow meters directly measure molecular flow (count gas molecules), so they provide the most reliable, repeatable and accurate gas measurement for power plant gas flow applications. In fact, with new developments in four-sensor thermal technology and software, some thermal flow meters have +/-0.5% accuracy which rivals the accuracy of Coriolis meters at a fraction of the cost. In some instances, you can also use vortex technology as an alternative depending on the gas flow application.
- Inlet Water to the Boiler -Power plant operators must also know how much water is going into the boiler to account for efficient steam production and detect any possible wasteful leaks. To measure inlet water flow to the boiler, the preferred method is clamp-on ultrasonic liquid flow meters. The benefits of this technology is that it is not affected by external noise, non-invasive with no pipe cutting and relatively easy to install. New advancements in ultrasonic technology now have on board software and apps that make the meter really easy to install, giving a “between goal posts” visual signal for a correct installation. Here is an example of an ultrasonic meter on the market for accomplishing this task.
- Steam Production – To determine the efficiency of steam production from the boilers, which is critical to turn the turbine for energy production, plant operators must get accurate steam flow measurement. Vortex shedding flow meters are ideal for measuring saturated and superheated steam as well as gases and liquids. Insertion vortex flow meters are ideal for large steam pipes with easy to use hot tap retractor. New technology and sensor advancement account for external vibration making the vortex flow meter even more accurate. New on board software apps also allow easy set up, tuning, trouble shooting, in-situ calibration validation, and datalogging.
How to Integrate Thermal Mass Flow Meters, Vortex and Ultrasonic Flow Meters into Power Plants
It is critical that all of the flow meters are seamlessly integrated into the process of a power plant. Recently, Sierra’s complete family of Flow Energy Management flow meters, coined the Big-3 (Thermal, Vortex, Ultrasonic), has been released and is perfect for accomplishing the task of integrating thermal, vortex and ultrasonic technology into power plants and other types of industrial flow processes. The beauty is that now plant operators can work with just one company to specify, install and maintain all their flow meters for all gas, steam, and liquid flow measurements. Sierra designs, manufactures and calibrates all our flow meters at our headquarters in Monterey, California USA to assure the best quality and lifetime support.
Other Sierra Big-3 advantages:
- Best-in-class sensor technology perfected over 40 years
- Shared Raptor OS iSeries operating system for high quality flow rate calculation
- On board software apps for easy set up, validation, tuning, gas mixing & datalogging
- Calibration expertise with high accuracy gas loop and water loop facilities
- Commissioning, global support over the lifetime of the product