CN101539447A

CN101539447A - U-shaped open channel supersonic flowmeter

Info

Publication number: CN101539447A
Application number: CN200910031233A
Authority: CN
Inventors: 彭世彰; 沈金荣; 缴锡云; 宋加才; 王莹; 韩金旭
Original assignee: Hohai University HHU
Current assignee: Hohai University HHU
Priority date: 2009-04-29
Filing date: 2009-04-29
Publication date: 2009-09-23

Abstract

The invention relates to a U-shaped open channel supersonic flowmeter based on embedded system technique. The U-shaped open channel supersonic flowmeter adopts a supersonic distance measuring principle to design a measuring circuit with high precision; according to U-shaped open channel roughness factor and water depth-over current section area curve which are measured by experiments, a singlechip calculates instantaneous flow and accumulating water delivery amount according to a mathematical model and displays, transmits and stores the data. The U-shaped open channel supersonic flowmeter has the remarkable characteristic that no weir or groove is arranged in an open channel when in use, the complete appliance has the advantages of no non-contact measurement head loss, little volume, light weight, electricity saving, simple installation, and the like and can be widely applied to open channel water delivery metering in agriculture, environmental protection, and the like.

Description

A kind of U type open channel supersonic flowmeter

One, technical field

The present invention is the open channel flow rate measuring technique of given shape, belongs to measure and field of measuring techniques.

Two, background technology

Along with the development of advanced practice of agronomy and the aggravation of shortage of water resources, water-saving irrigation technique is progressively promoted.Current China builds in a collection of water-saving efficient agricultural demonstration zone, and owing to cost and maintainable reason, building has a large amount of open channels to irrigate network, irrigates for extensive style in the past, need not to measure the flow of water.Nowadays the present measuring method of this class open channel flow rate generally all needs to be provided with the weir, as triangular-notch weir, rectangular weir etc., or the gutter channel of installation given shape, as Bashel groove etc., these devices are installed trouble, and the loss of flood peak is bigger, and this linking to canal irrigation region channels at different levels and field water level has brought difficulty, and therefore the mode of difficult employing weir or groove is carried out water gaging in the field irrigation place.According to the feed ditch characteristics in some large-scale irrigated areas, analyze and seek the loss of no head for this reason, cost is lower, and precision is higher is convenient to open channel flow rate measuring method and the device installed again.The open channel depth of water is measured by supersonic range finder; Through a large amount of experimental simulations, the calibration model parameter calculates U type open channel instantaneous delivery according to mathematical model by single-chip microcomputer, has promptly formed based on hyperacoustic flowmeter.

Three, summary of the invention

A kind of employing ultrasound wave that The present invention be directed to the measurement of U type open channel flow rate and design carries out non-contact measurement apparatus.The occasions such as open-channel flow measurement that can be widely used in all kinds of irrigated areas.

Technical scheme of the present invention: device is made up of hardware metering circuit, software program and shell, and hardware circuit is made up of single-chip microcomputer, ultrasonic probe, driving circuit, input loop, synchrolock, temperature compensation loop, memory module, LCD MODULE, keyboard input, D/A modular converter, RS232/485 communication module.The each several part circuit is connected by printed circuit board, can be installed on and form complete U type open channel flow rate measurement mechanism in the custom-designed shell.Only need during use this device reliably is installed on the support of open channel measuring point top, connect the 9-12DCV direct supply and can measure.

Instrument adopts time difference method to measure the open channel depth of water by ultrasound wave during measurement, and parameter and the mathematical model according to the experiment calibration calculates instantaneous delivery, accumulative total carrying capacity by single-chip microcomputer again.

The present invention's beneficial effect compared with the prior art is: measures the open channel flow rate existing equipment weir or groove must be set on channel, need construction to transform channel, and the cost height, and the loss of flood peak is bigger.This device need not to transform channel, only needs to set up mounting bracket can carry out non-cpntact measurement above channel, and measurement data can be by functions such as wired or wireless Network Transmission, data storage, and low in energy consumption, no head loss has extensive applicability.

Four, description of drawings

The hardware circuit figure of a kind of U type of Fig. 1 open channel supersonic flowmeter is made up of single-chip microcomputer, ultrasonic emitting probe, ultrasound wave receiving transducer, driving circuit, input loop, synchrolock, temperature compensation loop, memory module, LCD MODULE, keyboard input, D/A modular converter, RS232/485 communication module.

A kind of U type of Fig. 2 open channel supersonic flowmeter uses mounting structure figure, among the figure:

(1) U type channel;

(2) channel water bit line;

(3) ground level;

(4) be fixed on the support on ground;

(5) ultrasonic flow meter.

Five, embodiment

Hardware circuit is seen shown in Figure 1, the core cell single-chip microcomputer adopts ATmegal6L, and ultrasonic probe adopts 40KHz, and transmitting probe links to each other with single-chip microcomputer by driving circuit, receiving transducer links to each other with single-chip microcomputer by the input loop, and driving circuit and input loop are collaborative by synchrolock; Digital temperature integrated circuit DS18b20 is adopted in the temperature compensation loop, and its signal pins directly links to each other with single-chip microcomputer; Memory module adopts the 24C512 of EEProm, directly links to each other with single-chip microcomputer; LCD MODULE is selected Chinese lattice lcd modular LCD 12864 for use, links to each other with single-chip microcomputer by the serial communication mode; The keyboard load module is provided with four buttons, selects panel film contact button for use, has four signal wires to link to each other with single-chip microcomputer; The D/A modular converter adopts AD421, for the output of 4-20mA standard analog signal, only links to each other with single-chip microcomputer with three signal wires; The RS232/485 communication module adopts the chip MAX232 of MAX to realize level conversion, can carry out RS232 by the output of RS232-485 modular converter again and communicate by letter with RS485.The all hardware module is all fused by printed circuit board, is installed in the specific instrument shell and can forms complete measurement mechanism.

The Chezy formula of Manning roughness coefficient, the channel depth of water～discharge section area relation curve and the calculated flow rate that will be obtained by calibration experiment is stored in memory module, utilize single-chip microcomputer to select parameter according to actual conditions and calculate, thereby obtain the instantaneous delivery and the accumulative total carrying capacity of tested U type open channel.

Flowmeter uses to install sees Fig. 2, wherein: tested U type open channel (1), bury on plane, canal border district (3) and to adorn a support (4), in order to mounting ultrasonic flowmeter (5), make that flowmeter is stable can not rock that ultrasonic probe is the water surface (2) central authorities in the canal down, and make the highest water surface distance of probe distance more than 50cm, guarantee to avoid measuring the blind area, connect instantaneous delivery and integrated flow that the 12VDC power supply can be measured this open channel, these data can show, store or transmit.4 buttons of instrument can be realized the setting of measurement parameter, pattern.

Claims

1, a kind of U type open channel supersonic flowmeter, described device is a kind of instrument of special measurement U type open channel flow rate, it comprises hardware circuit, software program and shell three parts, it is characterized in that: (1) hardware circuit part is made up of single-chip microcomputer, ultrasonic probe, driving circuit, input loop, synchrolock, temperature compensation loop, memory module, LCD MODULE, keyboard input, D/A modular converter, RS232/485 communication module, and the each several part hardware circuit connects by circuit board; (2) flowmeter is fixed in open channel measuring point top by support; (3) flowmeter adopts time difference method to measure the open channel depth of water by ultrasound wave, and parameter and the mathematical model according to the experiment calibration calculates instantaneous delivery, accumulative total carrying capacity by single-chip microcomputer again.