Doppler ultrasonic flowmeter, and processor and method thereof with quantization error correction

• US 20050209793A1
• Filed: 02/25/2005
• Published: 09/22/2005
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Systems Company Limited
• Inventors: Ohmuro, Yoshinori, Yamada, Kazuyuki, Hirayama, Noritomo, Kishiro, Masami
• Granted Patent: US 7,584,065 B2
• Time in Patent Office: Days
• US Class Current: 702/45
• CPC Class Codes: G01F 1/663 by measuring Doppler frequency shift

Abstract

In a Doppler ultrasonic flowmeter, to obtain a precise flow rate a flow rate calculation equation that corrects a quantization error occurring to a spatial resolution is used. An ultrasonic transducer transmits/receives ultrasonic pulses, and subject the resulting received signals to A/D conversion after a predetermined process is applied thereto. A computation control section calculates the flow velocity distribution. Then, the flow rate is calculated based on the flow rate calculation equation, which corrects the quantization error occurring to the spatial resolution.

Claims

1. A Doppler ultrasonic flowmeter for measuring, using an ultrasonic Doppler shift, a flow rate of fluid flowing inside a conduit, comprising:

ultrasonic wave transmission/reception means for transmitting to the fluid an ultrasonic pulse with an arbitrary pulse repetition frequency, and for receiving a resulting ultrasonic echo to extract a Doppler shift component through a predetermined process;

flow velocity distribution calculation means for calculating a flow velocity distribution of the fluid based on the Doppler shift component extracted by the ultrasonic wave transmission/reception means; and

flow rate calculation means for calculating a flow rate of the fluid based on the calculated flow velocity distribution of a predetermined integration range and a quantization error occurring to a spatial resolution.

2. The Doppler ultrasonic flowmeter according to claim 1, wherein the flow rate calculation means corrects the quantization error by consideration only the region of the integration range occupied by a channel at a starting position and a channel at an end position of the integration range.

3. The Doppler ultrasonic flowmeter according to claim 1, wherein the flow rate calculation means calculates the flow rate (Q) based on the following equation:

4. The Doppler ultrasonic flowmeter according to claim 2, wherein the flow rate calculation means calculates the flow rate (Q) based on the following equation:

5. A processor in a Doppler ultrasonic flowmeter for measuring, using an ultrasonic Doppler shift, a flow rate of fluid flowing inside a conduit, comprising:

flow velocity distribution calculation means for calculating a flow velocity distribution of the fluid based on a Doppler shift component as a result of a predetermined process applied to a reception signal of an ultrasonic echo, which is a reflection wave of an ultrasonic pulse provided into the conduit; and

flow rate calculation means for calculating a flow rate based on the calculated flow velocity distribution of a predetermined integration range and a quantization error occurring to a spatial resolution.

6. The processor according to claim 5, wherein the flow rate calculation means corrects the quantization error by consideration only the region of the integration range occupied by a channel at a starting position and a channel at an end position of the integration range.

7. The processor according to claim 5, wherein the flow rate calculation means calculates the flow rate (Q) based on the following equation:

8. A method of computing a flow rate of fluid flowing inside a conduit in a Doppler ultrasonic flowmeter using an ultrasonic Doppler shift, the method comprising the steps of:

calculating a flow velocity distribution of the fluid based on a Doppler shift component as a result of a predetermined process applied to a reception signal of an ultrasonic echo, which is a reflection wave of an ultrasonic pulse provided into the conduit; and

calculating a flow rate of the fluid based on the calculated flow velocity distribution of a predetermined integration range and a quantization error occurring to a spatial resolution.

9. The method according to claim 8, wherein the calculation of the flow rate corrects the quantization error by consideration only the region of the integration range occupied by a channel at a starting position and a channel at an end position of the integration range.

10. The method according to claim 8, wherein the flow rate (Q) is calculated based on the following equation:

11. A storage device storing a computer program that contains codes for calculating the flow rate according to the method of claim 8.