A method for ultrasonic flow measurement

Abstract

The present invention relates to the technical field of ultrasonic flow measurement, and in particular to an ultrasonic flow measurement method, which comprises constructing an ultrasonic signal horizontal measurement surface on a transmission channel of the same fluid; arranging a first transmitting measurement sensor, a second transmitting measurement sensor and n reflection sensors in the measurement surface, obtaining the transmission time for the ultrasonic signal to reach the first transmitting measurement sensor, the n reflection sensors and the second transmitting measurement sensor, and calculating the gas flow rate and the medium sound velocity by a time difference method; compared with the prior art, the present invention can use fewer sensors and obtain multiple sets of data at one time when measuring the same sound channel, thereby solving the problems in the prior art of low single-channel measurement accuracy, high cost of one-to-one ultrasonic sensor setup required for multiple channels, multiple measurements required to obtain multiple sets of data, and failure of a single measurement surface affecting measurement accuracy and redundant backup.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic flow measurement, and in particular to an ultrasonic flow measurement method. Background Art

[0002] Ultrasonic flowmeters measure flow by observing ultrasonic waves, which are affected by the fluid and can reflect the fluid's flow rate. While there are many methods for using ultrasound to measure gas flow rate in pipelines, the time difference method is widely used because it is unaffected by factors such as temperature, pressure, and gas composition. For the same distance, the propagation time of sound waves is different in upstream and downstream conditions. By accurately measuring the upstream and downstream transit times, the velocity of the fluid being measured and, therefore, the flow rate, can be determined. The time difference method uses two symmetrically positioned ultrasonic sensors to measure the sound propagation time in both the forward and reverse directions, deriving the gas velocity and ultimately the flow rate.

[0003] Existing ultrasonic channel designs, whether through-beam, single-, or dual-reflection, all consist of two ultrasonic sensors per channel. The difference lies in the different sensor installation positions on the meter tube wall, creating a channel combination that covers a more comprehensive cross-section of the meter tube. Each pair of associated ultrasonic sensors constitutes an independent metering channel. Typically, to ensure relatively high measurement accuracy and redundancy, gas ultrasonic flowmeters for trade measurement use two or more channels. However, adopting a two-channel design (two pairs of ultrasonic sensors) or more would significantly increase costs. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides an ultrasonic flow measurement method to solve the problems in the existing technology of low single-channel measurement accuracy, high cost of setting up one-to-one ultrasonic sensors for multi-channels, and multiple measurements required to obtain multiple sets of data.

[0005] To achieve the above object, the present invention provides an ultrasonic flow measurement method, comprising the following steps:

[0006] Constructing an ultrasonic signal measurement surface on the transmission channel of the same fluid, wherein the measurement surface is parallel to the central axis of the transmission channel;

[0007] A first transmission measurement sensor, a second transmission measurement sensor, and n reflection sensors are arranged in the measurement plane. The n reflection sensors are evenly arranged on the transmission channel between the first transmission measurement sensor and the second transmission measurement sensor. The first transmission measurement sensor and the second transmission measurement sensor are both used to transmit and receive ultrasonic signals. The n reflection sensors are each used to receive ultrasonic signals and reflect the ultrasonic signal from the first transmission measurement sensor to the second transmission measurement sensor or reflect the ultrasonic signal from the second transmission measurement sensor to the first transmission measurement sensor, where n ≥ 1.

[0008] Acquiring the transmission time of the ultrasonic signal to the first transmission measurement sensor, the n reflection sensors, and the second transmission measurement sensor;

[0009] The gas flow rate and medium sound velocity are calculated by the time difference method.

[0010] Furthermore, the n reflection sensors, the first transmission measurement sensor, and the second transmission measurement sensor cooperate with each other to form a sound channel for ultrasonic signal transmission. The end faces of the reflection sensors are perpendicular to the measurement surface and intersect at the center line of the end faces of the reflection sensors. The central axes of the end faces of the first transmission measurement sensor and the second transmission measurement sensor both intersect with the centers of the end faces of adjacent reflection sensors, and the angles between the end faces and the central axis of the transmission channel are 15 to 75 degrees.

[0011] Furthermore, the acquired transmission time for the ultrasonic signal to reach the first transmitting measurement sensor, the n reflection sensors, and the second transmitting measurement sensor includes a forward transmission time and a reverse transmission time. The forward transmission time is the time taken to sequentially reach the n reflection sensors and the second transmitting measurement sensor along the transmission direction of the first transmitting measurement sensor, the n reflection sensors, and the second transmitting measurement sensor; the reverse transmission time is the time taken to sequentially reach the n reflection sensors and the first transmitting measurement sensor along the transmission direction of the second transmitting measurement sensor, the n reflection sensors, and the first transmitting measurement sensor.

[0012] Furthermore, n is an odd number, and the first emission measurement sensor and the second emission measurement sensor are both arranged on the same side of the transmission channel.

[0013] Furthermore, n=1, the first emission measurement sensor and the second emission measurement sensor are both arranged on the same side of the transmission channel, and the reflection sensor is arranged on the other side of the transmission channel opposite to the first emission measurement sensor and the second emission measurement sensor and opposite to the midpoint between the first emission measurement sensor and the second emission measurement sensor.

[0014] Furthermore, the forward transmission time includes the time t obtained when the first transmitting measurement sensor transmits an ultrasonic signal and the sound wave passes through the fluid and reaches the end face of the reflection sensor. AC , then reflected by the end face of the reflection sensor, the sound wave passes through the fluid again and reaches the end face of the second transmission measurement sensor, and the time quantity t is obtained. AB , calculate the time t for the sound wave to travel from the end face of the reflection sensor to the end face of the second transmission measurement sensor CB =t AB -t AC ;

[0015] The reverse transmission time includes the second transmitting measurement sensor transmitting an ultrasonic signal, the sound wave passing through the fluid and reaching the end face of the reflection sensor, and obtaining the time t BC , then reflected by the end face of the reflection sensor, the sound wave passes through the fluid again and reaches the end face of the first emission measurement sensor, and the time quantity t is obtained. BA , calculate the time t that the sound wave takes to travel from the end face of the reflection sensor to the end face of the second transmission measurement sensor CA =t BA -t BC .

[0016] Furthermore, n is an even number, and the first emission measurement sensor and the second emission measurement sensor are respectively arranged on both sides of the transmission channel.

[0017] Furthermore, n=2, the first emission measurement sensor and the second emission measurement sensor are respectively located on both sides of the transmission channel, the two reflection sensors are respectively and evenly arranged on both sides of the transmission channel between the first emission measurement sensor and the second emission measurement sensor, and the two reflection sensors are respectively the first reflection sensor and the second reflection sensor.

[0018] Furthermore, the forward transmission time includes the time t that the first transmitting measurement sensor transmits an ultrasonic signal, the sound wave passes through the fluid and reaches the end face of the first reflecting sensor. AC1 , then reflected by the end face of the first reflection sensor, the sound wave passes through the fluid again and reaches the end face of the second reflection sensor, and the time quantity t is obtained. AC2 The sound wave is reflected by the end face of the second reflection sensor, passes through the fluid and reaches the end face of the second transmission measurement sensor, and the time quantity t is obtained. AB The calculated time t for the sound wave to travel from the end face of the second reflection sensor to the end face of the second transmission measurement sensor is C2B =t AB -t AC2 , the amount of time t that it takes to travel from the end face of the first reflective sensor to the end face of the second reflective measurement sensor C1B =t AB -t AC1 The time it takes for the sound wave to travel from the end face of the first reflection sensor to the end face of the second reflection sensor is t C1C2 =t AC2 -t AC1 ;

[0019] The reverse transmission time includes the second transmitting measurement sensor transmitting an ultrasonic signal, the sound wave passing through the fluid and reaching the end face of the second reflecting sensor, and obtaining the time t BC2 , then reflected by the end face of the second reflection sensor, the sound wave passes through the fluid again and reaches the end face of the first reflection sensor, and the time quantity t is obtained. BC1The sound wave is reflected by the end face of the first reflection sensor, passes through the fluid and reaches the end face of the first transmission measurement sensor, and the time quantity t is obtained. BA , calculate the time t for the sound wave to travel from the end face of the first reflection sensor to the first transmission measurement sensor ultrasonic sensor C1A =t BA -t BC1 , the time it takes to travel from the end face of the second reflective sensor to the first transmitting measurement sensor ultrasonic sensor t C2A =t BA -t BC2 The time it takes for the sound wave to travel from the end face of the second reflection sensor to the end face of the first reflection sensor is t C2C1 =t BC1 -t BC2 .

[0020] Furthermore, a plurality of mutually parallel measuring surfaces are provided in the transmission channel of the same fluid.

[0021] Compared with the closest prior art, the present invention has the following beneficial effects:

[0022] The present invention arranges n reflection sensors on the transmission channel between the first transmitting measurement sensor and the second transmitting measurement sensor to obtain the transmission time of the ultrasonic signal reaching the first transmitting measurement sensor, the n reflection sensors and the second transmitting measurement sensor; 3n*2 time quantities are obtained, which is equivalent to 3n sound channels. If the one-to-one reflection or opposite reflection in the prior art is used, 2*(3n) measurement sites are required. Compared with the prior art, when the same sound channel measurement is achieved, a smaller number of sensors can be used, and multiple groups of data can be obtained at one time, which solves the problems in the prior art of low single-channel measurement accuracy, high cost of setting up one-to-one ultrasonic sensors for multiple channels, and multiple measurements required to obtain multiple groups of data; a plurality of parallel measurement surfaces are arranged in the transmission channel of the same fluid to improve the measurement accuracy and avoid the problem that the failure of a single measurement surface affects the measurement accuracy and redundant backup. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the through-beam flow metering method in the background art;

[0024] Figure 2 It is a flow chart of a reflective flow measurement method in the background art;

[0025] Figure 3 It is a schematic flow chart of an ultrasonic flow measurement method of the present invention;

[0026] Figure 4 1 is a schematic diagram of the ultrasonic flow measurement process when n is an odd number in Example 1 of the present invention;

[0027] Figure 5 1 is a schematic flow chart of ultrasonic flow measurement when n is an even number in Example 1 of the present invention;

[0028] Figure 6 1 is a schematic diagram of the flow chart of ultrasonic flow measurement according to embodiment 2 of the present invention;

[0029] Figure 7 It is a schematic diagram of the process of ultrasonic flow measurement in Example 3 of the present invention. DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] To make the technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0032] Figure 1 1 is a flow chart of a beam flow metering method in the background art, wherein A is a first beam measuring sensor and B is a second beam measuring sensor; Figure 1 It is AB single channel mode; Figure 2 It is a flow chart of the reflective flow measurement method in the background technology. Figure 2 The reflection in the transmission channel is reflected by the inner wall. A1 and B1 are a set of measurement channels, where A1 is the first emission measurement sensor and B1 is the second emission measurement sensor. A2 and B2 are a set of measurement channels, where A2 is the first emission measurement sensor and B2 is the second emission measurement sensor. Four measurement sites, i.e., four ultrasonic sensors, are used to complete the measurement of the two channels A1B1 and A2B2.

[0033] Example 1

[0034] Combine Figure 3 To illustrate, an ultrasonic flow measurement method includes the following steps:

[0035] S1. Construct an ultrasonic signal horizontal measurement surface on the transmission channel of the same fluid, with the measurement surface being parallel to the central axis of the transmission channel;

[0036] S2. Arrange a first transmission measurement sensor, a second transmission measurement sensor, and n reflection sensors within the measurement plane. The n reflection sensors are evenly arranged on the transmission channel between the first transmission measurement sensor and the second transmission measurement sensor. The first transmission measurement sensor and the second transmission measurement sensor are both used to transmit and receive ultrasonic signals. The n reflection sensors are each used to receive ultrasonic signals and reflect the ultrasonic signal from the first transmission measurement sensor to the second transmission measurement sensor or reflect the ultrasonic signal from the second transmission measurement sensor to the first transmission measurement sensor, where n ≥ 1.

[0037] The n reflection sensors, the first transmission measurement sensor, and the second transmission measurement sensor cooperate with each other to form a sound channel for ultrasonic signal transmission. The end faces of the reflection sensors are perpendicular to the measurement surface and intersect at the center line of the end faces of the reflection sensors. The central axes of the end faces of the first transmission measurement sensor and the second transmission measurement sensor both intersect with the centers of the end faces of adjacent reflection sensors, and the angles between the end faces and the central axis of the transmission channel are 15 to 75 degrees.

[0038] S3, obtaining the transmission time of the ultrasonic signal to the first transmission measurement sensor, the n reflection sensors, and the second transmission measurement sensor;

[0039] The transmission time amount for the ultrasonic signal to reach the first transmitting measurement sensor, the n reflection sensors, and the second transmitting measurement sensor includes a forward transmission time amount and a reverse transmission time amount. The forward transmission time amount is the time amount for the ultrasonic signal to reach the n reflection sensors and the second transmitting measurement sensor in sequence along the transmission direction of the first transmitting measurement sensor, the n reflection sensors, and the second transmitting measurement sensor; the reverse transmission time amount is the time amount for the ultrasonic signal to reach the n reflection sensors and the first transmitting measurement sensor in sequence along the transmission direction of the second transmitting measurement sensor, the n reflection sensors, and the first transmitting measurement sensor.

[0040] Assume that the first emission measurement sensor is A, the second emission measurement sensor is B, and the n reflection sensors are Cn.

[0041] The forward transmission time includes the n time quantities t that the ultrasonic signal emitted by the first transmitting measurement sensor reaches the end faces of the n reflecting sensors in sequence. ACn and the time it takes to reach the end face of the second emission measurement sensor, t AB , the time it takes for the ultrasonic signal to reach the end face of the second transmitting measurement sensor from the end face of the nth reflection sensor CnB =t AB -t ACn The time it takes for the ultrasonic signal to travel from the end face of the n-1th reflection sensor to the end face of the nth reflection sensor is t Cn-1Cn =t ACn -t ACn-1.

[0042] The reverse transmission time includes the n time quantities t that the ultrasonic signal emitted by the second transmitting measurement sensor reaches the end faces of the n reflecting sensors in sequence. BCn and the time it takes to reach the end face of the second emission measurement sensor, t BA , the time it takes for the ultrasonic signal to reach the end face of the first transmitting measurement sensor from the end face of the nth reflection sensor CnA =t BA -t BCn The time it takes for the ultrasonic signal to travel from the end face of the nth reflection sensor to the end face of the n-1th reflection sensor is t CnCn-1 =t BCn-1 -t BCn .

[0043] Therefore, a total of n groups t ACn and t CnA 、n group t CnB and t BCn 、n-1 groups t Cn-1Cn and t CnCn-1 and t AB and t BA The amount of time, a total of 3n*2 time amounts.

[0044] S4. Calculate the gas flow rate and medium sound velocity by the time difference method.

[0045] The gas ultrasonic flowmeter based on the time difference method derives the gas flow rate by measuring the transmission time of the upstream and downstream ultrasonic signals. That is, the direct measurement value is the amount of time measured by the ultrasonic sensor. The formula for the flow rate and sound speed using the time difference method is as follows:

[0046]

[0047]

[0048] Where: v is the gas velocity (m / s); C is the medium sound velocity (m / s); Lp is the length of the sound channel (m); α is the angle between the sound channel and the medium flow direction (or the central axis of the meter body); t 正向 is the time it takes for sound to travel forward in the sound channel; t 反向 It is the time it takes for the sound to travel in the opposite direction within the sound channel.

[0049] From the gas flow rate calculation formula, we can know that a sound channel detects two time quantities, the forward transmission time and the reverse transmission time, in a measurement cycle, and can complete the calculation of a flow rate value and deduce the flow value. The greater the amount of time information obtained by the same algorithm in the same time period, the more conducive it is to accurately and stably measure the gas flow.

[0050] This method obtains 3n*2 time quantities, which is equivalent to 3n sound channels. If the one-to-one reflection or reflection method in the existing technology is used, 2*(3n) measurement ultrasonic sensors are required. Compared with the existing technology, when measuring the same sound channel, fewer sensors can be used, and multiple sets of data can be obtained at one time. This solves the problems of low single-channel measurement accuracy in the existing technology, high setup cost of one-to-one ultrasonic sensors required for multiple channels, and multiple measurements required to obtain multiple sets of data.

[0051] Combine Figure 4 For illustration, when n is an odd number, the first emission measurement sensor and the second emission measurement sensor are both arranged on the same side of the transmission channel, and the n reflection sensors are evenly arranged on the transmission channel between the first emission measurement sensor and the second emission measurement sensor.

[0052] Combine Figure 5 For illustration, when n is an even number, the first emission measurement sensor and the second emission measurement sensor are respectively arranged on both sides of the transmission channel, and the n reflection sensors are evenly arranged on the transmission channel between the first emission measurement sensor and the second emission measurement sensor.

[0053] In order to avoid the problem that a failure of a single measuring surface affects the measurement accuracy and the redundancy backup, a plurality of mutually parallel measuring surfaces may be provided in the transmission channel of the same fluid.

[0054] Example 2

[0055] The difference from Example 1 is that n=1, the first emission measurement sensor and the second emission measurement sensor are both arranged on the same side of the transmission channel, and the reflection sensor is arranged on the other side of the transmission channel opposite to the first emission measurement sensor and the second emission measurement sensor and opposite to the midpoint between the first emission measurement sensor and the second emission measurement sensor.

[0056] The first emission measurement sensor is set as A, the second emission measurement sensor is set as B, and the reflection sensor is set as C.

[0057] The forward transmission time includes the time t obtained when the first transmitting measurement sensor transmits an ultrasonic signal and the sound wave passes through the fluid and reaches the end face of the reflection sensor. AC , then reflected by the end face of the reflection sensor, the sound wave passes through the fluid again and reaches the end face of the second transmission measurement sensor, and the time quantity t is obtained. AB , calculate the time t for the sound wave to travel from the end face of the reflection sensor to the end face of the second transmission measurement sensor CB =t AB -t AC ;

[0058] The reverse transmission time includes the second transmitting measurement sensor transmitting an ultrasonic signal, the sound wave passing through the fluid and reaching the end face of the reflection sensor, and obtaining the time t BC , then reflected by the end face of the reflection sensor, the sound wave passes through the fluid again and reaches the end face of the first emission measurement sensor, and the time quantity t is obtained. BA , calculate the time t for the sound wave to travel from the end face of the reflection sensor to the end face of the second transmission measurement sensor CA =t BA -t BC .

[0059] Two emission measurement sensors and one reflection sensor are used to obtain t AC and t CA , t AB and t BA , t CB and t BC There are 6 time quantities in total, which is half the number of sensors required to obtain 6 time quantities using the beam or reflection measurement method in the prior art.

[0060] Example 3

[0061] The difference from Example 1 is that n=2, the first emission measurement sensor and the second emission measurement sensor are respectively located on both sides of the transmission channel, and the two reflection sensors are respectively evenly arranged on both sides of the transmission channel between the first emission measurement sensor and the second emission measurement sensor, and the two reflection sensors are respectively the first reflection sensor and the second reflection sensor.

[0062] The first emission measurement sensor is set to A, the second emission measurement sensor is set to B, the first reflection sensor is set to C1, and the second reflection sensor is set to C2.

[0063] The forward transmission time includes the time t that the first transmitting measurement sensor transmits an ultrasonic signal, the sound wave passes through the fluid and reaches the end face of the first reflecting sensor. AC1 , then reflected by the end face of the first reflection sensor, the sound wave passes through the fluid again and reaches the end face of the second reflection sensor, and the time quantity t is obtained. AC2 The sound wave is reflected by the end face of the second reflection sensor, passes through the fluid and reaches the end face of the second transmission measurement sensor, and the time quantity t is obtained. AB , calculate the time t for the sound wave to travel from the end face of the second reflection sensor to the end face of the second transmission measurement sensor C2B =t AB -t AC2 , the amount of time t that it takes to travel from the end face of the first reflective sensor to the end face of the second reflective measurement sensor C1B =t AB -t AC1The time it takes for the sound wave to travel from the end face of the first reflection sensor to the end face of the second reflection sensor is t C1C2 =t AC2 -t AC1 .

[0064] The reverse transmission time includes the second transmitting measurement sensor transmitting an ultrasonic signal, the sound wave passing through the fluid and reaching the end face of the second reflecting sensor, and obtaining the time t BC2 , then reflected by the end face of the second reflection sensor, the sound wave passes through the fluid again and reaches the end face of the first reflection sensor, and the time quantity t is obtained. BC1 The sound wave is reflected by the end face of the first reflection sensor, passes through the fluid and reaches the end face of the first transmission measurement sensor, and the time quantity t is obtained. BA , calculate the time t for the sound wave to travel from the end face of the first reflection sensor to the first transmission measurement sensor ultrasonic sensor C1A =t BA -t BC1 , the time it takes to travel from the end face of the second reflective sensor to the first transmitting measurement sensor ultrasonic sensor t C2A =t BA -t BC2 The time it takes for the sound wave to travel from the end face of the second reflection sensor to the end face of the first reflection sensor is t C2C1 =t BC1 -t BC2 .

[0065] Two emission measurement sensors and two reflection sensors are used to obtain t AC1 and t C1A , t AC2 and t C2A , t AB and t BA , t C1C2 and t C2C1 , t C1B and t BC1 , t C2B and t BC2 There are 12 time quantities in total, which reduces the number of sensors used by 8 compared with the 12 sensors required to obtain 12 time quantities using the beam or reflection measurement method in the prior art.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. An ultrasonic flow measurement method, characterized in that: The following steps are involved: Constructing an ultrasonic signal measurement surface on the transmission channel of the same fluid, wherein the measurement surface is parallel to the central axis of the transmission channel; A first transmission measurement sensor, a second transmission measurement sensor, and n reflection sensors are arranged in the measurement plane. The n reflection sensors are evenly arranged on the transmission channel between the first transmission measurement sensor and the second transmission measurement sensor. The first transmission measurement sensor and the second transmission measurement sensor are both used to transmit and receive ultrasonic signals. The n reflection sensors are each used to receive ultrasonic signals and reflect the ultrasonic signal from the first transmission measurement sensor to the second transmission measurement sensor or reflect the ultrasonic signal from the second transmission measurement sensor to the first transmission measurement sensor, where n ≥ 1. Acquiring the transmission time of the ultrasonic signal to the first transmission measurement sensor, the n reflection sensors, and the second transmission measurement sensor; Calculate gas flow rate and medium sound speed by time difference method; Let the first emission measurement sensor be A, the second emission measurement sensor be B, and the n reflection sensors be Cn; Obtain n time quantities t for the ultrasonic signal emitted by the first transmitting measurement sensor to reach the end faces of n reflecting sensors in sequence ACn and the time it takes to reach the end face of the second emission measurement sensor, t AB , the time it takes for the ultrasonic signal to reach the end face of the second transmitting measurement sensor from the end face of the nth reflection sensor CnB= t AB -t ACn The time it takes for the ultrasonic signal to travel from the end face of the n-1th reflection sensor to the end face of the nth reflection sensor is t Cn-1Cn =t ACn -t ACn-1 The time it takes for the ultrasonic signal emitted by the second transmitting measurement sensor to reach the end faces of the n reflecting sensors in sequence is n times t BCn and the time it takes to reach the end face of the second emission measurement sensor, t BA , the time it takes for the ultrasonic signal to reach the end face of the first transmitting measurement sensor from the end face of the nth reflection sensor CnA= t BA- t BCn The time it takes for the ultrasonic signal to travel from the end face of the nth reflection sensor to the end face of the n-1th reflection sensor is t CnCn-1 =t BCn-1 -t BCn , a total of n groups of t ACn and t CnA 、n group t CnB and t BCn 、n-1 groups t Cn-1Cn and t CnCn-1 and t AB and t BA The amount of time, a total of 3n*2 time amounts.

2. The ultrasonic flow measurement method according to claim 1, characterized in that: The n reflection sensors, the first transmission measurement sensor, and the second transmission measurement sensor cooperate with each other to form a sound channel for ultrasonic signal transmission. The end faces of the reflection sensors are perpendicular to the measurement surface and intersect at the center line of the end faces of the reflection sensors. The central axes of the end faces of the first transmission measurement sensor and the second transmission measurement sensor intersect with the centers of the end faces of adjacent reflection sensors, and the angle α between the end faces and the central axis of the transmission channel is 15-75°.

3. The ultrasonic flow measurement method according to claim 2, characterized in that: The n is an odd number, and the first emission measurement sensor and the second emission measurement sensor are both arranged on the same side of the transmission channel.

4. The ultrasonic flow measurement method according to claim 3, characterized in that: The n=1, the first emission measurement sensor and the second emission measurement sensor are both arranged on the same side of the transmission channel, and the reflection sensor is arranged on the other side of the transmission channel opposite to the first emission measurement sensor and the second emission measurement sensor and opposite to the midpoint between the first emission measurement sensor and the second emission measurement sensor.

5. The ultrasonic flow measurement method according to claim 4, characterized in that: The forward transmission time includes the time t obtained when the first transmitting measurement sensor transmits an ultrasonic signal and the sound wave passes through the fluid and reaches the end face of the reflection sensor. AC , then reflected by the end face of the reflection sensor, the sound wave passes through the fluid again and reaches the end face of the second transmission measurement sensor, and the time quantity t is obtained. AB , calculate the time t for the sound wave to travel from the end face of the reflection sensor to the end face of the second transmission measurement sensor CB =t AB -t AC ; The reverse transmission time includes the second transmitting measurement sensor transmitting an ultrasonic signal, the sound wave passing through the fluid and reaching the end face of the reflection sensor, and obtaining the time t BC , then reflected by the end face of the reflection sensor, the sound wave passes through the fluid again and reaches the end face of the first emission measurement sensor, and the time quantity t is obtained. BA , calculate the time t that the sound wave takes to travel from the end face of the reflection sensor to the end face of the second transmission measurement sensor CA =t BA -t BC .

6. The ultrasonic flow measurement method according to claim 2, characterized in that: The n is an even number, and the first emission measurement sensor and the second emission measurement sensor are respectively arranged on both sides of the transmission channel.

7. The ultrasonic flow measurement method according to claim 6, characterized in that: The n=2, the first emission measurement sensor and the second emission measurement sensor are respectively located on both sides of the transmission channel, the two reflection sensors are respectively and evenly arranged on both sides of the transmission channel between the first emission measurement sensor and the second emission measurement sensor, and the two reflection sensors are respectively the first reflection sensor and the second reflection sensor.

8. The ultrasonic flow measurement method according to claim 7, characterized in that: The forward transmission time includes the time t that the first transmitting measurement sensor transmits an ultrasonic signal, the sound wave passes through the fluid and reaches the end face of the first reflecting sensor. AC1 , then reflected by the end face of the first reflection sensor, the sound wave passes through the fluid again and reaches the end face of the second reflection sensor, and the time quantity t is obtained. AC2 The sound wave is reflected by the end face of the second reflection sensor, passes through the fluid and reaches the end face of the second transmission measurement sensor, and the time quantity t is obtained. AB The calculated time t for the acoustic wave to travel from the end face of the second reflection sensor to the end face of the second transmission measurement sensor is C2B =t AB -t AC2 , the amount of time t that it takes to travel from the end face of the first reflective sensor to the end face of the second reflective measurement sensor C1B =t AB -t AC1 The time it takes for the sound wave to travel from the end face of the first reflection sensor to the end face of the second reflection sensor is t C1C2 =t AC2 -t AC1 ; The reverse transmission time includes the second transmitting measurement sensor transmitting an ultrasonic signal, the sound wave passing through the fluid and reaching the end face of the second reflecting sensor, and obtaining the time t BC2 , then reflected by the end face of the second reflection sensor, the sound wave passes through the fluid again and reaches the end face of the first reflection sensor, and the time quantity t is obtained. BC1 The sound wave is reflected by the end face of the first reflection sensor, passes through the fluid and reaches the end face of the first transmission measurement sensor, and the time quantity t is obtained. BA , calculate the time t for the sound wave to travel from the end face of the first reflection sensor to the first transmission measurement sensor ultrasonic sensor C1A =t BA -t BC1 , the time it takes to travel from the end face of the second reflective sensor to the first transmitting measurement sensor ultrasonic sensor t C2A =t BA -t BC2 The time it takes for the sound wave to travel from the end face of the second reflection sensor to the end face of the first reflection sensor is t C2C1 =t BC1 -t BC2 .

9. The ultrasonic flow measurement method according to any one of claims 1 to 8, characterized in that: A plurality of mutually parallel measuring surfaces are arranged in the transmission channel of the same fluid.

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