CN104697592A - Method for synchronously measuring ultrasonic wave flow - Google Patents

Abstract

The invention relates to the technical field of ultrasonic water meter, in particular to a method for synchronously measuring ultrasonic wave flow. The method comprises the step (A) of collecting and storing time difference delta t between fair flow and reverse flow of ultrasonic waves along fluid and the fluid temperature T simultaneously, wherein the Delta t, I, and Ti show data obtained from the i-th measurement respectively; the step (B) of utilizing the response time TRE of a temperature sensor to divide by a collecting period t in the data of the step A to obtain round-off numbers to get constant m; the step (C) of obtaining instantaneous velocity Vi of the fluid according to the time difference Delta ti collected at the i-th time, the fluid temperature Ti+m collected at the i+mth time and an equation; and the step (D) of calculating the fluid flow according to the instantaneous velocity Vi of the fluid. The obtained time difference Delta ti between the between fair flow and reverse flow of the ultrasonic waves along the fluid and the actual fluid temperature Ti+m corresponding to the time difference Delta ti serve as the data of the same group to be processed to gain the actual flow, the result is very accurate, and the phenomenon that when the parameter of the ultrasonic waves and the actual temperature are collected synchronously, the deviation occurs is avoided.

Description

Ultrasonic flow method for synchronously measuring

Technical field

The present invention relates to ultrasonic water meter technical field, particularly a kind of ultrasonic flow method for synchronously measuring.

Background technology

At present, for ultrasonic calorimeter and the water meter in various place, all will carry out temperature adjustmemt to parameters such as the time differences measured by it when calculated flow rate, and the temperature that current correction and computing method adopt is all the temperature measured measuring the time difference while.In fact, the temperature measured by platinum resistor temperature measuring sensor of current measuring tempeature has delayed time (often at about 15 seconds), so the computing method of current this nonsynchronous temperature adjustmemt are when there is very fast change in the temperature of measured fluid, there is error in the flow calculated, and, at short notice, in the more obvious situation of temperature variation, error is larger.

Summary of the invention

The object of the present invention is to provide a kind of ultrasonic flow method for synchronously measuring, the error caused because of temperature hysteresis can be avoided, improve the degree of accuracy of flow metering.

For realizing above object, the technical solution used in the present invention is: a kind of ultrasonic flow method for synchronously measuring, comprise the steps: that (A) gathers ultrasound wave along the time difference Δ t of fluid countercurrent current, following current and fluid temperature (F.T.) T simultaneously and store, wherein Δ t _i, T _irepresent respectively and measure the data obtained i-th time; (B) by the response time T of temperature sensor _rEdivided by data in steps A collection period t and round and obtain constant m; (C) the time difference Δ t collected according to i-th time _i, the fluid temperature (F.T.) T time to collect of the i-th+m _i+mand in following equations, solve the instantaneous velocity V of fluid _i: $V_i^2\·\mathrm{\Δ}{t}_i\·{\left(\cos \mathrm{\θ}\right)}^2+{2V}_i\·d-C_{i+m}^2\·{\mathrm{\Δt}}_i=0,$ Wherein, θ is the flow direction angle of hyperacoustic direction of propagation and fluid, d be upstream, downstream ultrasonic wave transducer along the spacing of fluid flow direction, C _i+mbe fluid temperature (F.T.) be T _i+mtime ultrasonic velocity; (D) according to the instantaneous velocity V of fluid _ifluid Computation flow: Q ∑ _isV _it, wherein, S is the sectional area of the pipeline supplying fluid to flow through.

Compared with prior art, there is following technique effect in the present invention: by the ultrasound wave that the collects time difference Δ t along fluid countercurrent current, following current _ireal fluid temperature T corresponding with it _i+mobtain actual flow as with group data processing, its result can very accurate, phenomenon devious when avoiding synchronous acquisition ultrasonic parameters and actual temperature.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in further detail.

A kind of ultrasonic flow method for synchronously measuring, comprises the steps: that (A) gathers ultrasound wave along the time difference Δ t of fluid countercurrent current, following current and fluid temperature (F.T.) T simultaneously and store, wherein Δ t _i, T _irepresent respectively and measure the data obtained i-th time; (B) by the response time T of temperature sensor _rEdivided by data in steps A collection period t and round and obtain constant m; (C) the time difference Δ t collected according to i-th time _i, the fluid temperature (F.T.) T time to collect of the i-th+m _i+mand in following equations, solve the instantaneous velocity V of fluid _i: $V_i^2\·\mathrm{\Δ}{t}_i\·{\left(\cos \mathrm{\θ}\right)}^2+{2V}_i\·d-C_{i+m}^2\·{\mathrm{\Δt}}_i=0,$ Wherein, θ is the flow direction angle of hyperacoustic direction of propagation and fluid, d be upstream, downstream ultrasonic wave transducer along the spacing of fluid flow direction, C _i+mbe fluid temperature (F.T.) be T _i+mtime ultrasonic velocity; (D) according to the instantaneous velocity V of fluid _ifluid Computation flow: Q ∑ _isV _it, wherein, S is the sectional area of the pipeline supplying fluid to flow through.Step C, that adopt when general fluid instantaneous velocity calculates is the time difference Δ t collected for i-th time _i, the fluid temperature (F.T.) T that i-th time collects _ithese two parameters carry out calculating, and in fact, the time difference Δ t collected for i-th time _icorresponding fluid temperature (F.T.) does not also collect due to the existence of hysteresis phenomenon, the fluid temperature (F.T.) T collected for i-th time direct in prior art _iin fact be not this time difference Δ t _icorresponding actual temperature, but before, therefore, can error be there is.But the present invention is then different, it collects the time difference Δ t collected for i-th time _iafter, at once do not process, but first store, by the time corresponding with it actual temperature numerical value T _i+mprocess again when collecting, the accuracy that fluid instantaneous velocity measures can be ensured like this, ensure the degree of accuracy of the fluid flow Q in step D further.

As preferred version of the present invention, in described step B, the response time T of temperature sensor _rEit is the integral multiple of collection period t.If not integral multiple, the time difference Δ t in step C _iwith fluid temperature (F.T.) T _i+mstill there is a little error, although this error very little be also exist, after adopting above-mentioned setting, avoid the existence of this error, ensure fluid temperature (F.T.) T _i+mjust be acquisition time difference DELTA t _itime corresponding actual temperature parameter, and when data processing, without the need to rounding, optimize processing speed.

Claims (2)

1. a ultrasonic flow method for synchronously measuring, comprises the steps:

(A) to gather ultrasound wave along the time difference Δ t of fluid countercurrent current, following current and fluid temperature (F.T.) T stores, wherein Δ t simultaneously _i, T _irepresent respectively and measure the data obtained i-th time;

(B) by the response time T of temperature sensor _rEdivided by data in steps A collection period t and round and obtain constant m;

(C) the time difference Δ t collected according to i-th time _i, the fluid temperature (F.T.) T time to collect of the i-th+m _i+mand in following equations, solve the instantaneous velocity V of fluid _i: wherein, θ is the flow direction angle of hyperacoustic direction of propagation and fluid, d be upstream, downstream ultrasonic wave transducer along the spacing of fluid flow direction, C _i+mbe fluid temperature (F.T.) be T _i+mtime ultrasonic velocity;

(D) according to the instantaneous velocity V of fluid _ifluid Computation flow: Q=∑ _isV _it, wherein, S is the sectional area of the pipeline supplying fluid to flow through.

2. ultrasonic flow method for synchronously measuring as claimed in claim 1, is characterized in that: in described step B, the response time T of temperature sensor _rEit is the integral multiple of collection period t.