The impact of geometric parameters of a S-type Pitot tube on the flow velocity measurements for greenhouse gas emission monitoring

Nguyen, Diep N.; Choi, Yong Moon; Lee, Saeng Hee; Kang, Wanmo

doi:10.1016/j.flowmeasinst.2019.03.002

Cited by 12 publications

(4 citation statements)

References 5 publications

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“…Assume that air is an incompressible gas. At this point, according to Bernoulli's equation: in an ideal flow field, the static pressure at the same height on the same flow line is equal everywhere, and the sum of its dynamic pressure is the total pressure [37], as shown in Equation (1).…”

Section: Wind Measurement Principlesmentioning

confidence: 99%

Wind Pressure Orthogonal Decomposition Anemometer: A Wind Measurement Device for Multi-Rotor UAVs

Hou

Xing

et al. 2023

Drones

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Wind speed and direction are critical meteorological elements. Multi-rotor unmanned aerial vehicles UAVs are widely used as a premium payload platform in meteorological monitoring. The meteorological UAV is able to improve the spatial and temporal resolution of the elements collected. However, during wind measurement missions, the installed anemometers are susceptible to interference caused by rotor turbulence. This paper puts forward a wind pressure orthogonal decomposition (WPOD) strategy to overcome this limitation in three ways: the location of the sensors, a new wind measurement method, and supporting equipment. A weak turbulence zone (WTZ) is found around the airframe, where the turbulence strength decays rapidly and is more suitable for installing wind measurement sensors. For the sensors to match the spatial structure of this area, a WPOD wind measurement method is proposed. An anemometer based on this principle was mounted on a quadrotor UAV to build a wind measurement system. Compared with a standard anemometer, this system has satisfactory performance. Analysis of the resulting data indicates that the error of the system is ±0.3 m/s and ±2° under hovering conditions and ±0.7 m/s and ±5° under moving conditions. In summary, WPOD points to a new orientation for wind measurement under a small spatial–temporal scale.

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Section: Wind Measurement Principlesmentioning

confidence: 99%

Wind Pressure Orthogonal Decomposition Anemometer: A Wind Measurement Device for Multi-Rotor UAVs

Hou

Xing

et al. 2023

Drones

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“…Thus, these correlations are taken into account in the uncertainty of the pitch calibration and the velocity calibration curves. In equation (10), a correlation exists between ΔP 45 and ΔP 12 . In equation (11), a correlation exists between ΔP 12 and ΔP std .…”

Section: Uncertainty From the Nulling Process U (δ Null )mentioning

confidence: 99%

“…Among these techniques, velocity measurements using the differential pressure with an S-type pitot tube are the most popular [9]. However, previous researchers pointed out that S-type pitot tubes can encounter limitations when installed in stacks with harsh environments, such as high gas temperatures, swirling flows, and large diameter stacks [10]. S-type pitot tubes can overestimate the flow by as much as 10% with the presence of non-axial velocity components [11].…”

mentioning

confidence: 99%

Calibration process and uncertainty estimation for 3D pitot tubes to enhance greenhouse gas emission measurements in smokestacks

Nguyen¹,

Choi²,

Im³

et al. 2022

Metrologia

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Carbon dioxide emissions made up from fossil fuel is a weighted contribution to the total carbon dioxide emissions in Korea. To keep on track of the long-term mitigation pathway, the new solution for enhancing the emission flow measurements more accurately in industrial smokestacks is urgent. Thus, along with the popular instrument, an S-type Pitot tube, three-dimensional Pitot tubes have been introduced to determine the emission flow in smokestacks by international standards and Korean regulations. To comply with the regulations mandated in Korea, the Korea Research Institute of Standards and Science established the three-dimensional Pitot tube calibration system for stack flow measurements assembled to the airspeed standard system. This calibration system can produce accurate pitch and velocity calibration curves for three-dimensional Pitot tubes in the range of testing pitch angle within ±30°, and have an expanded uncertainty attributed to the calibration curves (0.005 ~ 0.086) and (1.3~ 2.9)% for the prism Pitot tube and (0.008 ~ 0.175) and (1.6~3.1)% for the spherical Pitot tube.

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“…In this equation, ∆P denotes the differential pressure (Pa) between the impact and the wake orifices and ρ is the density of the emission gas (kg m −3 ). The S-type Pitot tube coefficient is determined by calibration in a national metrology institute or at an accredited calibration laboratory [18,21].…”

Section: Cems For On-site Energy and Industrial Fieldsmentioning

confidence: 99%

Uncertainty analysis of stack gas flow measurements with an S-type Pitot tube for estimating greenhouse gas emissions using a continuous emission monitoring system

et al. 2020

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In order to reduce greenhouse gas (GHG) emissions from producers in the energy and industrial fields to mitigate climate change more effectively, accurate and reliable studies of methods capable of estimating GHG emissions with proper uncertainty levels should initially be carried out. Continuous emission monitoring systems (CEMS) directly measure GHG emissions by measuring the GHG concentrations and volumetric flow rates of flue gases in smokestacks. Most studies of CEMS have tended to focus on the accuracy and uncertainty levels associated with GHG concentrations rather than on volumetric flow measurements. Particularly, the uncertainty associated with volumetric gas flow measurements by CEMS at a smokestack considering the individual plant must be determined to reduce the overall uncertainty. In the present study, the uncertainties of stack gas flow measurements with an S-type Pitot tube to estimate GHG emissions by CEMS are evaluated by applying the GUM and Monte Carlo methods to an on-site smokestack of an energy power plant. Velocity measurements in the stack were conducted using an S-type Pitot tube mainly used in Korea. The mathematical model equations of the accumulated volumetric gas flowrate measurements for estimating GHG emissions by CEMS are expressed in the form of detailed uncertainty equations by GUM. In the uncertainty evaluations by GUM, the combined standard uncertainty equation is expressed with the average gas flow velocity, stack diameter, static pressure, temperature and water content. The relative expanded uncertainty for volumetric gas flowrate measurements with an S-type Pitot tube in a smokestack by GUM is estimated to be 3.81% for a coverage factor (k = 2) at a confidence level of approximately 95%. In addition, the Monte Carlo method was applied to evaluate the associated uncertainty of volumetric gas flowrate measurements by an S-type Pitot tube for comparison with the results by the GUM method. The results of the uncertainty evaluations by GUM and MCM show good agreement, with only a 0.05% difference in the uncertainty outcomes.

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The impact of geometric parameters of a S-type Pitot tube on the flow velocity measurements for greenhouse gas emission monitoring

Cited by 12 publications

References 5 publications

Wind Pressure Orthogonal Decomposition Anemometer: A Wind Measurement Device for Multi-Rotor UAVs

Wind Pressure Orthogonal Decomposition Anemometer: A Wind Measurement Device for Multi-Rotor UAVs

Calibration process and uncertainty estimation for 3D pitot tubes to enhance greenhouse gas emission measurements in smokestacks

Uncertainty analysis of stack gas flow measurements with an S-type Pitot tube for estimating greenhouse gas emissions using a continuous emission monitoring system

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