Method and apparatus for measuring the flowrate of compressible fluids

Claim 2

Apparatus for determining the flowrate of a stream of compressible fluid comprising: a conduit for carrying the fluid; means in the conduit for impeding the flow of the fluid through said conduit; means for measuring the pressure of the fluid on the upstream and downstream sides of the impeding means; means for measuring the temperature of the fluid on both the upstream and downstream sides of said impeding means; and means for computing the flowrate of said fluid as a function of the differentials in pressure and temperature as measured on both the upstream and downstream sides of said impeding means.

Claim 3

Apparatus in accordance with claim 1 wherein the flowrate is computed in accordance with the following formula: ##EQU15## where P means Pressure T means Temperature R means Gas Constant Z means Compressibility Factor D means Diameter M means Molar Mass m means Mass Flowrate C p id means Ideal Gas Specific Heat per Mole ψ means f(temperature and Pressure of Fluid Points 1 and 2, and of the geometry also at points 1 and 2) g c means Mass/Force Conversion Factor.

Claim 4

Apparatus in accordance with claim 2 wherein said impeding means is adapted to maximize the temperature differential measured on both the upstream and downstream sides of said impeding means.

Claim 5

Apparatus in accordance with claim 3 wherein said temperature measuring means are positioned relatively distant from the walls of said conduit.

Claim 6

Apparatus in accordance with claim 4 wherein said pressure measuring means are positioned relatively distant from said impeding means.

Claim 7

Apparatus in accordance with claim 5 wherein said impeding means comprises a plate having an orifice therein.

Claim 8

Apparatus in accordance with claim 6 wherein said impeding means comprises a change in diameter of said conduit.

Claim 9

Method for determining the flowrate of a stream of a compressible fluid in a conduit having an impedance device therein, comprising the steps of: measuring the pressure of the fluid on the upstream side of the impedance device; measuring the pressure of said fluid on the downstream side of said impedance device; measuring the temperature of said fluid on said upstream side of said impedance device; measuring the temperature of said fluid on said downstream side of said impedance device; the preceding four steps being in any order; determining the difference in pressure between said upstream and downstream sides of said impedance device; determining the difference in temperature between said upstream and said downstream sides of said impedance device; the preceding two steps being in any order; and computing the flowrate of said fluid as a function of said differences in pressure and temperature.

Claim 10

Method for determining the flowrate of a stream of a compressible fluid in a conduit having an impedance device therein, comprising the steps of: measuring the pressure of the fluid on the upstream side of the impedance device; measuring the pressure of said fluid on the downstream side of said impedance device; measuring the temperature of said fluid on said upstream side of said impedance device; measuring the temperature of said fluid on said downstream side of said impedance device; the preceding four steps being in any order; determining the difference in pressure between said upstream and downstream sides of said impedance device; determining the difference in temperature between said upstream and said downstream sides of said impedance device; the preceding two steps being in any order; and computing the flowrate of said fluid as a function of said differences in pressure and temperature.

Claim 11

Method in accordance with claim 8 wherein the first four measuring steps are substantially contemporaneous.

Claim 12

Method in accordance with claim 9 wherein said computing step is performed in accordance with the following equation: ##EQU16## where P means Pressure T means Temperature R means Gas Constant Z means Compressibility Factor D means Diameter M means Molar Mass m means Mass Flowrate C p id means Ideal Gas Specific Heat per Mole ψ means f(temperature and Pressure of Fluid Points 1 and 2, and of the geometry also at points 1 and 2) g c means Mass/Force Conversion Factor.

Claim 13

Apparatus for determining the flowrate of a stream of compressible fluid, comprising: a conduit for carrying the fluid; a plate in said conduit having orifice therein, whereby the fluid flow may be impeded to create pressure and temperature differential thereacross; a first pressure sensor in said conduit on the upstream side of the plate; a second pressure sensor in said conduit on the downstream side of said plate; a first temperature sensor in said conduit on said upstream side of said plate; a second temperature sensor in said conduit on said downstream side of said plate; and means in communication with said first and second temperature sensors for computing the flowrate of said stream of fluid in accordance with the following formula: ##EQU17## where P means Pressure T means Temperature R means Gas Constant Z means Compressibility Factor D means Diameter M means Molar Mass m means Mass Flowrate C p id means Ideal Gas Specific Heat per Mole ψ means f(temperature and Pressure of Fluid Points 1 and 2, and of the geometry also at points 1 and 2) g c means Mass/Force Conversion Factor.

Claim 14

Apparatus for determining the flowrate of a stream of compressible fluid, comprising: a conduit for carrying the fluid; a plate in said conduit having orifice therein, whereby the fluid flow may be impeded to create pressure and temperature differential thereacross; a first pressure sensor in said conduit on the upstream side of the plate; a second pressure sensor in said conduit on the downstream side of said plate; a first temperature sensor in said conduit on said upstream side of said plate; a second temperature sensor in said conduit on said downstream side of said plate; and means in communication with said first and second temperature sensors for computing the flowrate of said stream of fluid in accordance with the following formula: ##EQU17## where P means Pressure T means Temperature R means Gas Constant Z means Compressibility Factor D means Diameter M means Molar Mass m means Mass Flowrate C p id means Ideal Gas Specific Heat per Mole ψ means f(temperature and Pressure of Fluid Points 1 and 2, and of the geometry also at points 1 and 2) g c means Mass/Force Conversion Factor.