The cavity flow quantity sensor
Technical field
The utility model relates to the device of measuring fluid flow, is a kind of cavity flow quantity sensor.
Background technology
In the big flow measurement of gases such as rock gas, coal gas field, the flowmeter that uses also only limits to differential pressure type (as orifice flowmeter, nozzle flowmeter, differential pressure type flowmeter etc.), turbo flow meter, vortex shedding flow meter or the like at present.Because these media generally all have bigger corrosivity, often contain more impurity and moisture again, belong to dirty fluid, to the burn into wearing and tearing of flowmeter, stop up and happen occasionally.In addition, the differential pressure flowmeter pressure loss is big, and the operating cost height is restricted in big flow measurement always; Turbines etc. have as easy as rolling off a log wearing and tearing of the flowmeter of movable member and damage, and maintenance cost is big; Vortex shedding flow meter is measured in bad working environment and is also had big problem, and fracture causes the accident as survey sensor.In a word, at present there are all difficulties in domestic and international existing flow instrument in the flow fashion of measuring such as high-pressure high-flow such as rock gas, coal gas or the dirty fluid of burn into.The accuracy of measurement of instrument, operating cost, installation and maintenance expense, the pressure loss etc. all remain in some problems.
Summary of the invention
The purpose of this utility model provides a kind of cavity flow quantity sensor, and it is the flowmeter that the principle of utilizing fluid flows amount meter pipeline to produce vibration along the wall cavity is made.Because flow measurement is only carried out in the cavity that tube wall forms, whole instrument does not have other again and hinders the parts that fluid flows, so the pressure loss of cavity flowmeter is very small, and is not afraid of and stops up and wearing and tearing.
The technical solution adopted in the utility model is:
It comprises that having joint flange and circulation duct forms flowmeter bodies, on the circulation duct wall, have one to measure cavity, measure on the cavity flow sensor is housed, temperature sensor and pressure transducer can be installed in respectively to be measured on the cavity or on the circulation duct, and is connected with intelligent integrator in being installed in instrument housing by lead-in wire respectively.
Flowmeter bodies is the circulation duct of a band joint flange, has the measurement cavity on the pipeline.When fluid flows through cavity, produce vortex in cavity, its vortex frequency and speed of incoming flow are proportional.The flow sensor of measuring vortex frequency is installed on the cavity, and the frequency of sensor output is relevant with the installation site.
Except flow sensor, temperature sensor and pressure transducer also are installed on the flowmeter bodies, the installation site is can reflect truly that ducted temperature and pressure is a principle.The temperature and pressure signal that sensor records is delivered to intelligent integrator with flow signal and is handled instantaneous delivery Q and the Q that obtains under work condition state or the standard state
0, integrated flux V and V
0Reach results such as temperature T, pressure P.And flow value can be converted to the output of normalized current signal, or communicate by letter with other intelligence instrument by serial ports.
The beneficial effect that the utlity model has:
1) flowmeter has adopted unique cavity structure, flow measurement is only carried out in the cavity that tube wall forms, whole instrument does not have other again and hinders the parts that fluid flows, more solid and reliable on the structure, be not afraid of problems such as burn into wearing and tearing, obstruction, the pressure loss is very small, and flowmeter operating cost almost can be ignored;
2) whole instrument has integral structure, and flow sensor can on-the-spotly be indicated flow value, can send the normal flow signal again;
3) adopt intellectualized technology to realize the temperature under the working condition, pressure are compensated and gas compressive coefficient is revised automatically automatically.
Description of drawings
Fig. 1 is a structural representation of the present utility model;
Fig. 2 is an integrator circuit structure block diagram of the present utility model;
Fig. 3 is an integrator circuit diagram of the present utility model.
Embodiment
As shown in Figure 1, it comprises that having joint flange 15 and circulation duct forms flowmeter bodies 14, on the circulation duct wall, have one to measure cavity 13, measure on the cavity 13 flow sensor 17 is housed, temperature sensor 11 and pressure transducer 12 can be installed in respectively to be measured on the cavity 13 or on the circulation duct, and is connected by the lead-in wire intelligent integrator interior with being installed in instrument housing 6 respectively.
Flowmeter bodies 14 comprises the circulation duct of a band joint flange 15, has one to measure cavity 13 on the pipeline wall.Measure cavity and be welded on by steel plate on the tube wall of fluting, load onto cavity cover plate 18 by trip bolt and form.When fluid flows through cavity, produce vortex in cavity, its vortex frequency and speed of incoming flow are proportional.The flow sensor of measuring vortex frequency just is installed in to be measured on the cavity, and the installation site is determined by experiment.The frequency of sensor output is relevant with cavity shape.
Flow sensor 17 is installed in the center of connector 10, and signal is sent to intelligent integrator by column 8 middle signal cables.Column is compressed by nut 9 and installs on the connector 10.Except flow sensor 17, temperature sensor 11 and pressure transducer 12 also are installed on the flowmeter bodies 14, the installation site is can reflect truly that ducted temperature and pressure is a principle.Can be installed in and measure on the cavity 13, also can be installed on the circulation duct.The temperature and pressure signal that sensor records is delivered to intelligent integrator with flow signal and is handled instantaneous delivery Q and the Q that obtains under work condition state or the standard state
0, integrated flux V and V
0Reach results such as temperature T, pressure P.And flow value can be converted to the output of normalized current signal, or communicate by letter with other intelligence instrument by serial ports.
Intelligence integrator 3 is installed in the instrument housing 6, instrument housing by protecgulum 1 and bonnet 7 with intelligent integrator seal protection.Packing ring 2, glass sheet 3, baffle ring 4 and back-up ring 5 are housed on the protecgulum, form a sealed transparent system, so that reading.The normalized current signal that intelligence instrument converts to, serial digital signal etc. are by remote transfer signal line outlet (16) output.
As shown in Figure 2, said intelligent integrator comprises instrumentation amplifier 26, prime amplifier 19, is built-in with mould/microprocessor 25, power-supply system 24, RS485 interface circuit 20, the display module 23 of number conversion circuit and eeprom memory; The instrumentation amplifier 26 that the signal of temperature sensor 11 and pressure transducer 12 is formed via operational amplifier 2254 respectively connects the mould/number conversion circuit in the microprocessor 25; The prime amplifier 19 that the signal of flow sensor 17 is formed through prefix operation amplifier 7611 connects microprocessor 25; After microprocessor 25 receives temperature, pressure and flow signal,, be connected on the display 23 that can demonstrate flow and temperature, pressure value through integrating and compensation operation; Microprocessor 25 connects through D/A 21 outputs 4~20mA normalized current signal, or connects RS485 interface 20 delivery rate digital signals to other subscriber equipment 22, and button 27 is set on the microprocessor 25.
Said measurement cavity 13 be shaped as rectangle or semicircle or polygon.
As shown in Figure 3, the temperature and pressure signal of being experienced by temperature sensor 11 and pressure transducer 12 is delivered to the instrumentation amplifier 26 that amplifier 2254 forms respectively and is amplified, and the temperature after the amplification, pressure signal are given microprocessor 25 built-in A/D converters to convert digital quantity to standby; Flow signal is measured by flow sensor 17, and is shaped to frequency and the proportional pulse signal of flow by prime amplifier 19 amplifications that amplifier 7611 is formed, and directly gives microprocessor 25.Microprocessor is accumulated each traffic pulse according to the instrument coefficient K that presets, and reaches K pulse and just interrupts refreshing integrated flux V; The umber of pulse that unit interval records is just represented instantaneous delivery Q.Convert according to the temperature, pressure value that measures and to get instantaneous delivery Q under the standard state
0With integrated flux V
0Above-mentioned all results not only can indicate on the spot by display module 23, also can convert analog quantity to by D/A converter 21, output 4~20mA normalized current signal; Can also communicate by letter with other smart machine 22 by RS485 interface circuit 20 delivery rate digital signals.Intelligent instrument system has the low-power consumption characteristic, and power-supply system 24 can be powered by outside 24V, also can be by the 3.6V powered battery.Constants such as the used instrument coefficient K of system works, flow range, temperature, pressure scope, sample rate can be finished setting by button 27 is set.All are measured Presentation Function and are finished by software control.