CN2624182Y

CN2624182Y - Intelligent vortex street flow gauge

Info

Publication number: CN2624182Y
Application number: CN 03234208
Authority: CN
Inventors: 张川潮
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-04-28
Filing date: 2003-04-28
Publication date: 2004-07-07
Anticipated expiration: 2013-04-28

Abstract

The utility model discloses an intelligent flowmeter of vortex street, comprising a display instrument disc, a supporting bracket, a body shell, a pressure sensor, a vortex generator and a stress sensor; wherein, one end of the vortex generator is provided with a blind hole; two platinum resistances are arranged in the blind hole and have certain distance away from each other. The utility model is endorsed both with the detecting techniques of stressed vortex street flow and thermal differing flow; therefore, the measuring range of the vortex street flowmeter is greatly enlarged, and the reliability and stability of the measuring range lower limit of the vortex street flowmeter is increased. The measurable flow speed of gas is reduced to 0.5 m/s and the measurable flow speed of fluid is reduced to 0.05 m/s.

Description

A kind of intelligent vortex shedding flowmeter

Technical field the utility model relates to a kind of intelligent vortex shedding flowmeter.

The background technology vortex shedding flow meter begins development, the heated filament detection method that has been born vortex shedding flow meter the end of the sixties.70, the development eighties is developed the vortex shedding flow meter of multiple detection method, as ultrasonic, magnetosensitive, strain, stress etc. rapidly.Vortex shedding flow meter belongs to the row of universal flow, has developed many kinds both at home and abroad, and there is dozens of manufacturer in the whole nation.Vortex shedding flow meter is wide with its measurement range, output pulse signal and irrelevant with temperature, pressure and the component of measured medium be characteristics.Have a kind of name to be called " intelligent vortex shedding flowmeter ", the patent No. is the patented technology of ZL00254621, its improvement is that former flowmeter inner chamber is a straight-run of pipe, and the Taper Pipe that now inner chamber is changed into straight-run of pipe and two sections symmetries is formed, the straight tube two ends are the Taper Pipe that has certain taper; This kind flowmeter can increase its measurement range, the range extension ratio, but still following deficiency is arranged: 1. the principle of work of vortex shedding flow meter has limited it to hanging down the adaptability of flow velocity; 2. at the measurement gas flow velocity less than 5 meter per seconds, rate of flow of fluid is during less than the fluid of 0.5 meter per second, can't measure substantially or measuring error very big; 3. the stability of measurement result and reliability are not high.

Summary of the invention the utility model is of the prior art above not enough in order to overcome, and a kind of intelligent vortex shedding flowmeter that vortex street measuring technique and platinum resistance thermometer sensor, thermal different type measuring technique are combined is provided.

The technical solution of the utility model: a kind of intelligent vortex shedding flowmeter, it comprises display dial, bracing frame, table body shell, pressure transducer, vortex generation body, strain gauge, it is characterized in that: there is a blind hole at the middle part at described vortex generation body one end, through hole in this blind hole and the vortex generation body is connected, and has and the corresponding hole of blind hole at the corresponding site of table body shell; Upper and lower at a distance of two platinum resistance of certain distance installation in blind hole; It also comprises the control circuit that contains one-chip computer.

The model of above-mentioned one-chip computer is MSP430, its 2 pin, 3 pin are connected with the hot difference detecting circuit of platinum resistance, 4 pin are connected with pressure transducer, 12 pin are connected with the vortex signal testing circuit, 37,38,39,40,63,64 pin are connected with the corresponding interface of LCD plate, and 52,54,55,56,57,58,63,64 pin are as DLL (dynamic link library).

Flowmeter of the present utility model combines stress-type vortex street flow detection technology and thermal different type flow detection technology, has expanded the range of vortex shedding flow meter greatly, has improved the reliability and stability of vortex shedding flow meter range lower limit; The measurable flow speed of gas is reduced to 0.5 meter per second, the measurable flow speed of liquid is reduced to 0.05 meter per second.

Description of drawings below in conjunction with accompanying drawing to the utility model is described in further detail:

Fig. 1 is the utility model structural drawing.

Fig. 2 is vortex street vortex generation body (part a 5) front view.

Fig. 3 is vortex street vortex generation body (part a 5) vertical view.

Fig. 4 is the utility model circuit diagram.

Fig. 5 is the utility model workflow diagram.

Embodiment (referring to Fig. 1), in the intelligent vortex shedding flowmeter of the present utility model, 1 is that display dial, 2 is that bracing frame, 3 is that pressure transducer, 5 is that vortex generation body, 6 is that strain gauge, 7 is platinum resistance thermometer sensor, for showing body shell, 4.Flowmeter of the present utility model is on the basis of original stress-type vortex street flowmeter, and vortex generation body 5 is done suitably to improve, and processes the blind hole of an appropriate depth therebetween, as mounting hole, installs two inside up and down at a distance of the platinum resistance 7 of certain distance.Certainly, also to process corresponding hole, be communicated with this blind hole to settle platinum resistance thermometer sensor, or lead etc. at the corresponding site of flowmeter table body shell 3.In platinum resistance thermometer sensor, thermal different type flow rate detection technology, all will be with two platinum resistance thermometer sensor,s, the normal thermometric of conduct is used, another strengthens the certain range of excitation electric current and makes himself heating, will take away the part heat when having fluid to flow through and cause that temperature descends, control system (single-chip microcomputer) in the detecting device detects the variation of the temperature difference of two platinum resistance thermometer sensor,s, thereby calculates the flow velocity size in the pipeline.

(referring to Fig. 2, Fig. 3), this two width of cloth accompanying drawing have shown a kind of concrete structure (ratio and Fig. 1 of this two width of cloth accompanying drawing are variant) of vortex generation body 5.The cross sectional shape of this vortex generation body 5 roughly is trapezoidal, and a blind hole 8 is arranged at the middle part of one end, and this blind hole 8 should be connected with the through hole 9 in the vortex generation body 5, and the through hole 9 in the vortex generation body is not further described as prior art.

(referring to Fig. 4), intelligent vortex shedding flowmeter is controlled by one-chip computer, and vortex street strain gauge 6 enters into one-chip computer with detected vortex signal form with rect.p. after amplifying shaping, calculates flow velocity and flow after the one-chip computer acquired signal.Platinum resistance thermometer sensor, thermal different type flow rate detection circuit is made up of the platinum resistance thermometer sensor, 7 in two vortex generation bodies 5 that are encapsulated in vortex shedding flow meter, constant current source on the circuit board and amplifying circuit and one-chip computer.The variation that one-chip computer is gathered the temperature difference of two platinum resistance thermometer sensor,s can calculate the interior flow velocity size of pipeline.The effect of this circuit is except guaranteeing when flow velocity is higher than preset lower limit, flowmeter comes calculated flow rate with vortex street stress-type detection method, when flow velocity is lower than preset lower limit, flowmeter comes outside the calculated flow rate with platinum resistance thermometer sensor, thermal different type detection method, also wants the dependable flow meter freely to change between two kinds of detection methods.The model of the one-chip computer in this accompanying drawing is MSP430, its 2 pin, 3 pin are connected with the hot difference detecting circuit of platinum resistance, 4 pin are connected with pressure transducer, 12 pin are connected with vortex street stress-type testing circuit, 37,38,39,40,63,64 are connected with the corresponding interface of LCD plate, and 52,54,55,56,57,58,63,64 pin are as DLL (dynamic link library).Hot difference detecting circuit of platinum resistance in this accompanying drawing and vortex street stress-type testing circuit be all as custom circuit of the prior art, not as protection domain, be not further described.

(referring to Fig. 5), workflow of the present utility model is: start → put vortex street sampling sign F=1 → timing sampling cycle → judgements sampling and indicate whether F equals 1;

1. if F=1 then sample → judges to vortex street whether flow velocity is lower than lower limit;

2. if flow velocity is not less than lower limit, then continue temperature and pressure compensation sampling → calculated flow rate → demonstrations → judgements time in sampling period to denying, as if to then returning following one-period,, return following one-period again as if not to waiting for that then the time in sampling period arrives.

3. be lower than lower limit if judge sampling sign F ≠ 1 or flow velocity, then greater than lower limit deny to heat difference sampling → calculating flow velocity → judgement flow velocity;

4. if flow velocity greater than lower limit, then put vortex street sampling sign, if flow velocity is not more than lower limit, then put heat difference sampling sign, all continue temperature and pressure compensation sampling → calculated flow rate → demonstration → time in sampling period of judgement then to denying, if to then returning following one-period,, return following one-period again as if not to waiting for that then the time in sampling period arrives.

Claims

1. intelligent vortex shedding flowmeter, it comprises display dial, bracing frame, table body shell, pressure transducer, vortex generation body, strain gauge, it is characterized in that: the end at described vortex generation body (5) has a blind hole (8), through hole (9) in blind hole (8) and the vortex generation body (5) is connected, and has and the corresponding hole of blind hole (8) at the corresponding site of table body shell (3); Upper and lower at a distance of certain distance installation two platinum resistance (7) in blind hole (8); It also comprises the control circuit that contains one-chip computer.

2. a kind of intelligent vortex shedding flowmeter according to claim 1, it is characterized in that: the model of described one-chip computer is MSP430, its 2 pin, 3 pin are connected with the hot difference detecting circuit of platinum resistance, 4 pin are connected with pressure transducer, 12 pin are connected with the vortex signal testing circuit, 37,38,39,40,63,64 pin are connected with the corresponding interface of LCD plate, and 52,54,55,56,57,58,63,64 pin are as DLL (dynamic link library).