Efficiency improvements can significantly impact the bottom line due to the high energy costs associated with running steam applications, which can make up as much as half of total process energy expenditures.
Fortunately, cutting-edge steam flow meter technology provides insight into steam usage, allowing for the optimization of steam for greater efficiency and lower costs.
By making the best choice for steam flow measurement, you can do away with potential leaks, adjust for fluid density changes, incorporate temperature sensors, reduce maintenance needs, and cut down on flow errors.
Right Flowmeter Technology For Power Generation To Measure Natural Gas, Water, And Steam
Many chemical factories employ a nearby natural gas power plant or a cogeneration plant that burns waste gas streams to generate energy. The combustion of air and fuel (often natural gas, waste gas, oil, or coal) in huge boilers at power plants generates thermal energy. When water is heated, it boils and releases steam. When steam is directed through a turbine, it spins and produces power.
Improving energy efficiency, finding waste, and reducing emissions of greenhouse gases (GHG) all depend on accurate measurements of the flow of energy (flows of fuel that cost money) in various boiler applications. Users can only make educated choices to increase energy efficiency with precise flow measurements.
Regarding boiler applications, how do end users choose which steam flow meter technology is ideal for measuring gas, water, and steam? Flowmeters should be carefully selected, considering the fluid being monitored. There are primarily three uses in mind when discussing ways to increase boiler efficiency:
– Efficient combustion requires precise measurement of the incoming air and fuel (natural gas, waste gas, oil, or coal).
– Steam generation efficiency and waste detection using inlet feedwater metering.
– Calculating the amount of steam released by the appliance.
Increase the air-to-fuel ratio
Combustion of air and fuel is essential to the production of electricity. Engineers must precisely monitor the air-to-gas ratio for proper combustion in the boilers. Using too much gas can be harmful and expensive while using too little won’t generate a strong enough flame to bring the water to a boil.
Typical examples of such measuring devices are orifice and turbine meters. Orifice or turbine meters have often been used to measure fuel gas flow to the boiler units. However, these are only some of the most trustworthy measuring tools because they break down often and necessitate regular expert repair.
Engineers can also experience stress from confined plumbing conditions. An orifice meter, for instance, needs upstream piping with a diameter of 10-50 to remove the impact of flow disturbances.
Since extended stretches of straight pipe are uncommon, most flow measurement devices suffer from inaccurate readings caused by the pipe’s ever-changing flow profile.
The fact that volumetric flow is measured by both orifice and turbine meters is the primary cause for alarm. Mass flow can be calculated or inferred using a flow computer and supplementary pressure, temperature, and differential pressure sensors.
The accuracy of the flow measurement suffers, and the total cost of ownership rises due to the higher expenditures of setup and upkeep associated with compensated measurement.
Mass flow thermometers. Direct mass flow measurement of gases is what thermal mass flowmeters excel at, not volumetric flow measurement. Mass flow can be measured directly, without correction for changes in inlet temperature and pressure, with thermal mass flowmeters.
For this reason, thermal flowmeters excel in inlet air and gas flow boiler applications where the optimum fuel-to-air ratio for efficient combustion is computed on a mass basis rather than a volumetric one.
Accurate input feedwater measurements
Water is a scarce and costly form of flow energy. Accurately measuring the entrance feedwater flow into a boiler is essential for gauging the boiler’s effectiveness at converting water into steam in boiler applications.
Ultrasonic flowmeters that can be attached with a clamp. Clamp-on ultrasonic flowmeters are appropriate for water flow applications due to their ease of use and versatility, though volumetric vortex flowmeters can be used to measure inlet water.
They are accurate at low and high flows, don’t require pipe cutting or shutting down the process, and are immune to outside noise. The meter may now be installed with minimal effort thanks to developments in ultrasonic technology; furthermore, visual confirmation of a successful installation is provided using onboard software and apps.
Improve steam output efficiency
Accurate steam measurements from the boiler are required to ascertain if it produces the desired amount of steam or needs to be tuned for greater efficiency. Historically, a differential pressure device, such as an orifice plate, has been used to quantify steam flow.
However, by their very nature, such instruments measure volumetric flows. The mass flow rate of steam is sensitive to changes in pressure and temperature. The uncompensated mass flow will be off by 10% for even a “small” 10% drop in steam pressure.
Therefore, the volumetric flow rate must be corrected by measuring temperature and pressure in a standard differential pressure system. A flow computer uses these three measurements (P, T, and P) to determine mass flow.
Multivariable vortex insertion flowmeters. Multivariable vortex flowmeters inserted into boilers improve the accuracy with which steam output is measured. Mass flow rate, temperature, pressure, volume, and fluid density can be measured using an steam flow meter with only one process connection.
Since the density of saturated steam changes with either temperature or pressure, and the density of superheated steam changes with both, multivariable steam flow meters guarantee accurate density calculations and, by extension, accurate mass steam flow measurements.