Flow rate measurement device, fuel efficiency measurement device, program for flow rate measurement device and flow rate measurement method

Patent metadata

Field	Value
Publication number	US-10041406-B2
Application number	US-201615365205-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Dec 15, 2015
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

In order to provide a flow rate measurement device that can measure a flow rate of a sample fluid passing a tube body with high accuracy even though temperature irregularity of the sample fluid generates along a radial direction of the tube body, the flow rate measurement device comprise a temperature measurement device that measures a mean temperature of a sample fluid discharged from an internal combustion engine or temperature distribution of the sample fluid along a radial direction of the tube body, and a flow rate of the sample fluid is measured based on the mean temperature or the temperature distribution measured by the temperature measurement device.

First claim

What is claimed is:

1. A flow rate measurement device that comprises a temperature measurement device that measures a mean temperature of a sample fluid that flows in a tube body or temperature distribution of the sample fluid along a radial direction of the tube body, and that measures a flow rate of the sample fluid based on the mean temperature or the temperature distribution measured by the temperature measurement device, wherein the sample fluid is an exhaust gas that is discharged from an internal combustion engine and that flows in the tube body, and wherein the temperature measurement device measures the mean temperature of the exhaust gas that is discharged from the internal combustion engine and that flows in the tube body or the temperature distribution of the exhaust gas along the radial direction.

2. The flow rate measurement device described in claim 1 , wherein
the flow rate measurement device comprises a pair of ultrasonic wave transmitter-receivers and measures the flow rate of the sample fluid based on a propagation time of an ultrasonic wave that passes and propagates through the sample fluid between the pair of ultrasonic wave transmitter-receivers, and
the temperature measurement device calculates the mean temperature of the sample fluid based on the propagation time.

3. The flow rate measurement device described in claim 1 , wherein
the temperature measurement device calculates the mean temperature of the exhaust gas further based on an air-fuel ratio of the internal combustion engine measured by a predetermined air-fuel ratio sensor.

4. The flow rate measurement device described in claim 1 , wherein
the flow rate measurement device comprises a pair of ultrasonic wave transmitter-receivers and calculates the flow rate of the exhaust gas based on a difference between a reciprocal number of a propagation time of an ultrasonic wave that propagates in an upstream direction of the exhaust gas between the pair of the ultrasonic wave transmitter-receivers and a reciprocal number of a propagation time of an ultrasonic wave that propagates in a downstream direction of the exhaust gas between the pair of the ultrasonic wave transmitter-receivers, wherein
the flow rate of the exhaust gas is calculated further based on a temperature of the exhaust gas calculated from a sum of the reciprocal numbers.

5. A fuel efficiency measurement device comprising
the flow rate measurement device described in claim 1 , and
a fuel efficiency calculation device that calculates fuel efficiency based on the flow rate of the exhaust gas measured by the flow rate measurement device.

6. A non-transitory computer readable storage medium that stores a program that is loaded on a flow rate measurement device that comprises
a temperature measurement device that measures a mean temperature of a sample fluid that flows in a tube body or temperature distribution of the sample fluid along a radial direction of the tube body, and that measures a flow rate of the sample fluid based on the mean temperature or the temperature distribution measured by the temperature measurement device, and
a pair of ultrasonic wave transmitter-receivers and a calculation part that calculates a flow rate of a sample fluid based on a propagation time of an ultrasonic wave that passes through the sample fluid and that propagates between the pair of ultrasonic wave transmitter-receivers, wherein
the calculation part is provided with a function of calculating a mean temperature of the sample fluid based on the propagation time and a function of calculating the flow rate of the sample fluid based on the mean temperature,
the sample fluid is an exhaust gas that is discharged from an internal combustion engine and that flows in the tube body, and
the temperature measurement device measures the mean temperature of the exhaust gas that is discharged from the internal combustion engine and that flows in the tube body or the temperature distribution of the exhaust gas along the radial direction.

7. A flow rate measurement method comprising
measuring a mean temperature of a sample fluid that flows in a tube body or temperature distribution of the sample fluid along a radial direction of the tube body and
measuring a flow rate of the sample fluid based on the measured mean temperature or the measured temperature distribution, wherein the sample fluid is an exhaust gas that is discharged from an internal combustion engine and that flows in the tube body, and wherein the mean temperature or the temperature distribution is measured along the radial direction.

Assignees

• Horiba Ltd

Inventors

• Akita Masanobu

Classifications

• G01F1/668 Primary

  Compensating or correcting for variations in velocity of sound · CPC title

• F02B77/084 Primary

  indicating economy · CPC title

• F01N11/00

  Monitoring or diagnostic devices for exhaust-gas treatment apparatus · CPC title

• F01N2560/12

  Other sensor principles, e.g. using electro conductivity of substrate or radio frequency · CPC title

• G01M15/102

  by monitoring exhaust gases · CPC title