Open channel ultrasonic flow rate measuring system
The utility model belongs to the ultrasonic flow rate field of measuring technique, is specifically related to a kind of open channel ultrasonic flow rate system.This Flow Measuring System can be applied to build canals, the flow metering in river etc.
Along with population growth, economic development and living standards of the people improve, water resource becomes the strategic resource that involves the interests of the state and the people day by day.Investigation, assessment and the planned reasonable utilization of water resource become the important function of country.Therefore, to the metering of water resource, the especially discharge of river and channel metering, significant.
The main method of open channel or river discharge measurement at present has: liquid level method and flow velocity area-method.
The liquid level method is mainly according to the hydraulics ultimate principle, when water flows through the groove of standard or weir (typical in Pa Xieer groove, triangular-notch weir, rectangular weir, wide sharp-crested weir), flow becomes certain functional relation with liquid level, flows through the liquid level of standard section by measurement, is converted into flow.Level gauging can be manual range estimation, also can utilize the ultrasound wave location to measure automatically.The flow measurement precision of these class methods is generally ± and about 3%.Its advantage is to measure simply, and precision is higher; Shortcoming is relatively more difficult for the channel of transversal section broad or river course construction, and quantities is very big, and long-term the use influenced by sedimentation, and precision can descend.
The flow velocity area-method is measured mean flow rate and the liquid level on the transversal section in channel or river course simultaneously, obtains cross-sectional area according to liquid level, thus calculated flow rate.Can be divided into manual fish lead formula and automatic measurement formula according to the measuring principle difference; Can be divided into extended immobilization formula and boating type according to the working method difference; Can be divided into single-point (single channel) formula and multiple spot (hyperchannel) formula again according to the flow-speed measurement method difference.Method for automatic measurement relatively more commonly used at present mainly is to utilize ultrasonic time difference method or ultrasound Doppler's method to measure single-point (single channel) or multiple spot (hyperchannel) mean flow rate, utilizes pressure transducer or ultrasonic measuring liquid level simultaneously.
Ultrasonic time difference method adopts single channel or channel ultrasonic to measure the mean flow rate of different depth layer on river course or the channel transversal section, and the while measuring liquid level is according to speed and liquid level calculated flow rate.The level gauging precision can reach ± and 0.5%, the flow velocity precision can reach ± and 1%, measure rivers and canals width suitable for reading and can reach hundreds of rice.Its advantage is to measure very wide river course or channel, but because port number is limited, and the flow measurement precision is not high usually, can't normally measure when liquid level is very low, and with high costs, and the installation difficulty is big.
Ultrasound Doppler's method utilizes Doppler's principle to measure the flow velocity of road along the river or channel direction, and with ultrasound wave or pressure transducer measuring liquid level.Be divided into single-point type, multipoint mode and ADCP according to the mode of testing the speed; Be divided into boating type and fixed according to working method.
The flow velocity that the fixed acoustic doppler velocimeter of single-point utilizes Doppler's principle to measure certain point in river course or the channel replaces the mean flow rate of transversal section; The single-point boating type is then finished whole river course or channel transversal section multiple spot fluid-velocity survey by walking the aerial survey amount, and calculates the mean flow rate of whole section; The multipoint mode acoustic doppler velocimeter fixedly lays a plurality of single-point current meters on river course or channel transversal section, measure the flow velocity of multiple spot, calculates the mean flow rate of transversal section with this; Fixed ADCP calculates mean flow rate by measuring the layering flow velocity of road along the river or channel cross-sectional direction (Width); Boating type ADCP then by walking the aerial survey amount, obtains the degree of depth layering flow velocity at broad ways diverse location place, calculates the mean flow rate of whole section in view of the above.This shows that boating type ADCP measurement point density is higher than fixed ADCP usually, fixed ADCP measurement point density is higher than the single-point boating type, and it is fixed that single-point boating type measurement point density is higher than multiple spot, and it is fixed that the fixed measurement point density of multiple spot is higher than single-point.Therefore, boating type ADCP flow measurement precision is the highest in theory, and fixed ADCP precision is taken second place, the single-point boating type takes second place again, and multiple spot is fixed to take second place again, and the fixed measuring accuracy of single-point is minimum, but meanwhile, equipment complexity, measuring process complexity and equipment cost are also successively from high to low.Boating type measuring process complexity, the single measurement cost is very high, only is applicable to interim measurement; ADCP flow measuring device complexity and cost are all very high, and the user is difficult to bear.
In sum, under the condition that precision allows, the fixed or fixed ultrasonic Doppler fluid-velocity survey of the multiple spot equipment of single-point can satisfy the needs of long-term continuous monitoring, can save cost again, and is economical and practical, is the main flow that present river or canal capacity are measured.
The existing fixed ultrasonic flow rate measuring system of single-point mainly adopts under water integral type or pops one's head under water that formula realizes.Integral type all places all measurements and memory device under water under water, it is waterborne to have only power supply and communication interface to place, regularly manually take data away and charge the battery, the shortcoming of this mode be the user can't intuitive judgment equipment normally whether, in case equipment failure or power supply deficiency will obliterated datas, in addition, show not intuitively, the user's modification device parameter is also very inconvenient.The formula under water of popping one's head in then only places ultrasonic transducer and necessary pre-amplification circuit under water, and that signal processing part is placed in is waterborne, and this mode often only is applicable to portable use.Its shortcoming is that signal transmission distance is bigger when river course or channel broad, thereby decay is very big, and signal to noise ratio (S/N ratio) is very low, and the problem solution is bad altogether, damages instrument easily.
The utility model is exactly a kind of new embodiment of the fixed flow measurement mode of single-point.
The utility model content
The utility model has overcome that untimely, the real-time demonstration of integral type flowmeter fault alarm under water is directly perceived, the inconvenient shortcoming of parameter modification, and the formula flowmeter cable distance weak point under water of popping one's head in, can not be applicable to the shortcoming of big river of width or channel, Flow Measuring System adopts split-type structural under water waterborne.Above water is a main control equipment, is responsible for tasks such as power supply power supply, data storage and transmission, demonstration, warning; Underwater portion is a measuring equipment, is responsible for the measurement of liquid level, mean flow rate.The two communicates by 485 mouthfuls, finishes control command and data transmission.
Above-mentioned purpose of the present utility model is achieved by the following technical solutions:
(1) native system comprises waterborne and two parts under water; Above water is a main control equipment, and underwater portion is a measuring equipment;
(2) main control part comprises power module, display module, memory module and communication module;
(3) measure portion comprises power module, ultrasonic emitting module, ultrasound wave receiver module, Doppler signal detecting module, pressure transducer level gauging circuit module, temperature-measuring module, signal processing module and communication module;
(4) communicate connection by 485 mouthfuls between main control equipment and the measuring equipment.Main control equipment sends the measurement instruction by 485 mouthfuls to measuring equipment; Measuring equipment then returns to main control equipment by 485 mouthfuls with measurement result;
(5) main control equipment to module for power supply under water, is then turned off power supply, to reduce power consumption At All Other Times when measuring;
(6) measuring equipment receives the main control equipment instruction in the back that powers on, and begins to measure.Utilize ultrasound Doppler's method to measure mean flow rate, by the pressure transducer measuring liquid level, measuring water temperature utilizes the flow velocity area-method to calculate instantaneous delivery and integrated flux simultaneously; Measurement result is finished one-shot measurement after returning to main control equipment;
(7) ultrasonic probe of measuring equipment, pressure transducer, temperature sensor all adopt split-type structural, can independent test, be easy to standardization and replacing;
(8) main control equipment is stored current measurement result, show, reports to the police when breaking down, and sends to command centre by wireless or wire communication facility;
(9) command centre transfers historical summary at any time, revises parameter current by wireless or wireline equipment, and measurement data is carried out aftertreatment.
Technique effect of the present utility model has:
(1) owing to adopt split-type structural, with respect to integral structure under water, can in time show the work at present state, find that fault in time reports to the police, and can revise Instrument working parameter at any time;
(2) the main control part lower module power supply of just feeding water when measuring helps reducing power consumption;
(3) 485 port communications can transmit big distance, and with respect to the formula structure under water of popping one's head in, native system goes for the river of big width or the measurement of channel;
(4) marine equipment can be connected with command centre by wired or wireless mode, makes things convenient for command centre to transfer historical summary, inquiry current state, modification parameter at any time, and helps networking;
(5) split type ultrasonic probe, pressure transducer, temperature sensor make independent debugging be more prone to, and are easy to standardized production.
Description of drawings
Below in conjunction with accompanying drawing, the utility model is made detailed description.
Fig. 1 is the high-level schematic functional block diagram of the utility model underwater portion;
Fig. 2 is the above-water high-level schematic functional block diagram of the utility model;
Fig. 3 is the utility model monnolithic case synoptic diagram.
With reference to figure 1, Fig. 2, Fig. 3, the utility model is realized the open channel ultrasonic flow rate measuring system of a split-type structural under water waterborne.Comprise:
With reference to figure 1, underwater portion: power module 12 is to the entire circuit power supply, and signal processor 11 produces emissioning controling signal, generates the waveform that transmits by signal generator 13, after power amplifier 14 amplifications, by ultrasonic receipts transducer T radiate supersonic wave in water; The scatter echo signal that particle or bubble produce in the water is received by ultrasonic transducer R, be amplified to certain amplitude through signal amplifier 15, detect Doppler signal, be input to signal processor 11 and carry out spectrum analysis by wave detector 16, obtain the frequency spectrum of Doppler signal, and calculate mean flow rate in view of the above; Pressure transducer 17, temperature sensor 16 produce liquid level and temperature signal respectively in addition, are fed to signal processor 11, obtain liquid level and temperature in view of the above.
With reference to figure 2, Fig. 3, above water: to power module 22 power supplies, produce the various power supplys of circuits needed by battery 28, primary controller 21 is finished the management of total system, by by key control 25, accept the various parameter settings and the manual operation instruction of button 38, send order by communication module 26 to underwater portion according to setup parameter, finish measurement, receive measurement result, and measurement result is stored in the memory module 24, by display module 23 result is presented on the nixie display 39 simultaneously; Primary controller 21 can also pass through communication module 27 external computing machine or MODEM, is connected with control center.
With reference to figure 3, shown the contour structures of whole measuring system.Underwater portion is by shell 31, upper cover plate 32 forms gas-tight silo 33, gas-tight silo is the place of placing circuit board, ultrasonic probe is installed in the skewed slot 35 of front end of gas-tight silo, simultaneously also be provided with pressure transducer storehouse 34 at the gas-tight silo front end, the rear end of gas-tight silo is provided with perforate 36 and is used to wear cable 37 and is connected to above water; Above water is encapsulated in the instrument box, and instrument face plate is provided with button 38 and shows charactron 39, is used for parameter setting and result and shows.
In sum, the utility model discloses a kind of open channel ultrasonic flow rate measuring system and its implementation.Above-described application scenarios and embodiment; be not to be used to limit the utility model, any those skilled in the art are not in breaking away from spirit and scope of the present utility model; therefore can do various changes and retouching, protection domain of the present utility model is looked the claim scope and is defined.