Non-nulling gas velocity measurement apparatus and performing non-nulling measurement of gas velocity parameters

Patent metadata

Field	Value
Publication number	US-11525840-B2
Application number	US-202117231468-A
Country	US
Kind code	B2
Filing date	Apr 15, 2021
Priority date	Apr 16, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A non-nulling gas velocity measurement apparatus performs a non-nulling measurement of gas velocity parameters and includes: a non-nulling pitot probe; gas valves in fluid communication with a different entrant aperture of the non-nulling pitot probe via a different pressure channel; receives stagnant gas from the respective entrant aperture; receives a reference gas; receives a valve control signal; and produces a valve-selected gas based on the valve control signal, the valve-selected gas consisting essentially of the reference gas or the stagnant gas; and a plurality of differential pressure transducers, such that each differential pressure transducer: is separately and independently in fluid communication with a different gas valve, and that gas valve communicates the valve-selected gas to the differential pressure transducer; receives the valve-selected gas from the gas valve; and produces a differential pressure signal from comparison of the pressure of the valve-selected gas to a reference gas pressure.

First claim

What is claimed is:

1. A non-nulling gas velocity measurement apparatus for performing non-nulling measurement of gas velocity parameters, the non-nulling gas velocity measurement apparatus comprising:
a non-nulling pitot probe comprising:
an aerodynamic flow head comprising a plurality of entrant apertures that comprises a central entrant aperture and a plurality of peripheral entrant aperture arranged radially from the central entrant aperture, such that the entrant apertures receive a gas flow from a gas source;
an entrant body tube disposed on the aerodynamic flow head;
an extensor body tube disposed on the entrant body tube such that the entrant body tube is interposed between the aerodynamic flow head and the extensor body tube, such that extensor body tube is arranged at an oblique angle to the entrant body tube; and
a plurality of pressure channels disposed in the aerodynamic flow head, the entrant body tube, and the extensor body tube, such that each entrant aperture is separately and independently in fluid communication with one of the pressure channels, and each pressure channel independently receives and communicates the gas flow as stagnant gas from the entrant aperture of which the pressure channel is in communication; and

a plurality of gas valves such that each gas valve:
is in fluid communication with a different entrant aperture of the non-nulling pitot probe via a different pressure channel;
receives stagnant gas from the respective entrant aperture;
receives a reference gas;
receives a valve control signal; and
produces a valve-selected gas based on the valve control signal, the valve-selected gas consisting essentially of the reference gas or the stagnant gas; and

a plurality of differential pressure transducers, such that each differential pressure transducer:
is separately and independently in fluid communication with a different gas valve, and that gas valve communicates the valve-selected gas to the differential pressure transducer;
receives the valve-selected gas from the gas valve;
receives the reference gas at a reference gas pressure;
compares a pressure of valve-selected gas to the reference gas pressure; and
produces a differential pressure signal from comparison of the pressure of the valve-selected gas to the reference gas pressure.

2. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising a plurality of sample gas lines, such that each sample gas line separately interconnects one pressure channel with one of the gas valves for communicating the gas flow received by the respective entrant aperture to the respective gas valve as the stagnant gas.

3. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising a plurality of valve outlet gas lines, such that each valve outlet gas line separately interconnects one gas valve with one of the differential pressure transducers for communicating the valve-selected gas from the gas valve to the respective differential pressure transducer.

4. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising a reference gas line in communication with each gas valve and that communicates the reference gas to the gas valves.

5. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising a reference gas line in communication with each differential pressure transducer and that communicates the reference gas to the differential pressure transducers.

6. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising a reference pressure source that provides the reference gas to each gas valve.

7. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising a reference pressure source that provides the reference gas to each differential pressure transducer.

8. The non-nulling gas velocity measurement apparatus of claim 1 , further comprising an analyzer in communication with each differential pressure transducer and that:
receives each differential pressure signal from each differential pressure transducer; and
produces a gas velocity parameters from the differential pressure signal.

9. The non-nulling gas velocity measurement apparatus of claim 8 , further comprising a controller in communication with each gas valve and that:
produces a plurality of valve control signals; and
communicates the valve control signals, such that each gas valve receives one of the valve control signals from the controller and produces valve-selected gas based on the valve control signal.

10. The non-nulling gas velocity measurement apparatus of claim 9 , wherein the controller further produces a control signal; and communicates the control signal to the analyzer, such that the control signal indicates whether each gas valve produces valve-selected gas from the stagnant gas or the reference gas.

11. The non-nulling gas velocity measurement apparatus of claim 1 , wherein the gas source is an emission stack.

12. The non-nulling gas velocity measurement apparatus of claim 1 , wherein the aerodynamic flow head comprises a hemispherical surface over which gas flow flows to be received by the entrant aperture that are arranged in the hemispherical surface.

13. The non-nulling gas velocity measurement apparatus of claim 1 , wherein the aerodynamic flow head comprises a conical surface over which gas flow flows to be received by the entrant aperture that are arranged in the conical surface.

14. The non-nulling gas velocity measurement apparatus of claim 1 , wherein the differential pressure signal from the plurality of differential pressure transducers provide a determination of gas velocity parameters that comprise turbulence intensity, velocity vector, static pressure, or density of gas flow.

15. The non-nulling gas velocity measurement apparatus of claim 1 , wherein the gas flow comprises a Mach number from 0.01 to 0.3 at a velocity that is from 5 m/s to 100 m/s.

16. A process for performing non-nulling measurement of gas velocity parameters, the process comprising:
receiving, by an analyzer, a zeroth differential pressure signal, first differential pressure signal, a second differential pressure signal, and third differential pressure signal;
producing a zeroth calibrated pressure CP 0 from the zeroth differential pressure signal, a first calibrated pressure CP 1 from the first differential pressure signal, a second calibrated pressure CP 2 from the second differential pressure signal, and a third calibrated pressure CP 3 from the third differential pressure signal;
removing a dependence of a reference gas pressure P 0 of a reference gas from the zeroth calibrated pressure CP 0 , the first calibrated pressure CP 1 , the second calibrated pressure CP 2 , and the third calibrated pressure CP 3 to produce, respectively, a first adjusted pressure AP 1 , a second adjusted pressure AP 2 , and a third adjusted pressure AP 3 ;
combining the first adjusted pressure AP 1 , the second adjusted pressure AP 2 , and the third adjusted pressure AP 3 to obtain a pseudo-dynamic pressure scalar;
individually normalizing the first adjusted pressure AP 1 , the second adjusted pressure AP 2 , and the third adjusted pressure AP 3 with the pseudo-dynamic pressure scalar to produce, respectively, a first reduced pressure RP 1 , a second reduced pressure RP 2 , and a third reduced pressure RP 3 ;
determining a real dynamic pressure from the first reduced pressure RP 1 , the second reduced pressure RP 2 , and the third reduced pressure RP 3 ;
determining a yaw angle or a pitch angle of the gas flow from the first red

Assignees

• Government Of The Us Secretary Of Commerce

Inventors

• Shinder Iosif Isaakovich
• Johnson Aaron Nathaniel
• Filla Bernard James

Classifications

• G01F1/34

  by measuring pressure or differential pressure · CPC title

• G01P5/16 Primary

  using Pitot tubes {, e.g. Machmeter} · CPC title

• G01P5/165

  Arrangements or constructions of Pitot tubes · CPC title

• G01F1/46

  Pitot tubes · CPC title

• G01P13/045

  with speed indication · CPC title