CN104198020B - A kind of flow calibration instrument based on static weighing method - Google Patents

Abstract

The invention discloses a flow rate meter based on a static weighing method, which belongs to a large-scale experimental measuring instrument and includes a water distribution tank, a weighing water tank, an electronic scale and a control box. The water distribution tank is used to quickly switch the direction of water flow, the weighing water tank is used to load the total amount of water flow within a certain period of time, the electronic scale is used to measure the weight of water, and the control box is used to control the entire system, collect, analyze and automatically process data. The beneficial effect of the invention is that all parts are integrated into a whole, and automatic control and accurate calculation and analysis are realized, which facilitates accurate measurement of pipeline flow.

Description

A flow meter based on static weighing method

technical field

The invention belongs to the technical field of flow measurement, and relates to a device for measuring pipeline flow, in particular to a flow measurement and calibrating device capable of integrated operation.

Background technique

Accurate measurement of flow is very important to various fields of national economy such as water conservancy, hydropower, chemical industry, petroleum, hydraulic construction, agriculture and environmental protection. At present, modern electronic flow devices such as electromagnetic flowmeters, differential pressure flowmeters, ultrasonic flowmeters, and Doppler flowmeters are widely used in the measurement of pipeline flow and open channel flow, and they can be used to measure dynamic flow changes. The basic principle of these devices is to convert the flow rate into an electrical signal through a sensor, and then convert the electrical signal into a digital signal. However, when these devices are used for a certain number of years, the built-in sensors will drift. At the same time, these devices are greatly affected by temperature and installation environment, so in many cases, other high-precision flow measurement devices must be used to calibrate them.

Contents of the invention

In order to calibrate the electronic flow measuring device equipped with sensors, the present invention provides a flow rate based on static weighing method that can not only accurately measure the flow rate of the constant flow of the pipeline, but also calibrate the electronic flow measuring device. fixed instrument.

The technical solution adopted in the present invention is: a flow rate meter based on static weighing method, which is characterized in that it includes an electronic scale, a weighing water tank, a water distribution tank, a high-speed cylinder, an air compressor, a reversing switch, and a control box , steel brackets, connecting rods; the high-speed cylinder is provided with two air inlets and outlets of the high-speed cylinder, which are respectively the head inlet and outlet and the tail inlet and outlet, and the upper part of the weighing water tank is provided with a water inlet of the weighing water tank; The water distribution tank is a double-layer three-chamber structure, and the inside of the water distribution tank is divided into upper and lower layers by the set return chute and the slider that fits with the chute. plate, which divides the lower layer of the water distribution tank into independent left chamber and right chamber, the lower part of the left chamber is provided with a first drain port, and the lower part of the right chamber is provided with a second drain port, and the second drain port is provided at the lower part of the right chamber. The second drain port is connected to the water inlet of the weighing water tank through a pipe; the bottom surface of the slider is attached to the top surface of the partition plate, and can slide left and right in the return chute; The weighing water tank mentioned above is placed on the electronic scale without mechanical contact with any other devices, and is located in the inner cavity of the steel bracket; the water distribution tank, high-speed cylinder, reversing switch, air compressor Sequentially installed on the upper beam of the steel bracket; the piston rod of the high-speed cylinder is fixedly connected with the slider through the connecting rod, and the air compressor is connected with the reversing switch through the air pipe connected, the reversing switch is respectively connected to the air inlet and outlet of the two high-speed cylinders through the air pipe; when the air compressor supplies air to the head of the high-speed cylinder through the air pipe from the air inlet and outlet of the head, thereby driving the The connecting rod pushes the slide plate in the water distribution tank to slide leftward in the chute, then the right chamber can be opened and the left chamber can be closed, and water can be filled into the weighing water tank through the second discharge port and the water inlet of the heavy water tank; The air compressor supplies air to the tail of the high-speed cylinder through the air pipe from the inlet and outlet of the tail, thereby driving the connecting rod to push the slide plate in the water distribution tank to slide to the right in the chute, and the left chamber can be opened and the right chamber can be closed , and drain the water flow outward through the first water outlet; the control box is respectively connected with the electronic scale, the high-speed cylinder and the reversing switch through the signal line, and the control box controls the reversing switch To the switch operation cylinder gas supply direction, and the action of the high-speed cylinder, and automatically collect all data, automatically analyze the data and calculate the flow.

Preferably, the data includes: the time of the connecting rod moving to the right, the time of the connecting rod staying, the time of the connecting rod moving to the left, and the weight of the water body.

As a preference, the high-speed cylinder is fixedly installed on the upper beam of the steel bracket through an adjustable fixed support, and the piston rod and the connecting rod are on the same axis.

Preferably, a sealing ring is provided where the connecting rod passes through the outer wall of the upper layer of the water distribution box.

As a preference, the outer wall of the weighing water tank is provided with a third drain for outward drainage when the water body of the weighing water tank reaches a certain amount; the bottom of the weighing water tank is provided with a fourth drain for when the weighing water tank reaches a certain amount. Drain the water outside when servicing the weighing water tank.

The beneficial effects of the present invention are: the whole set of integrated device adopts automatic control, which can conveniently and effectively measure the flow and calibrate the flow meter; the high-speed cylinder is used to control the slider, which can speed up the switching speed of water flow, so as to measure the flow accurately.

Description of drawings

Fig. 1: the structural representation of the embodiment of the present invention;

Fig. 2: the three-dimensional internal structural view of the water distribution tank of the embodiment of the present invention;

Fig. 3: the front view of the water distribution tank of the embodiment of the present invention;

Fig. 4: the flow measurement principle of the embodiment of the present invention;

Figure 5: Calibration results of the electromagnetic flowmeter of the embodiment of the present invention.

detailed description

In order to facilitate those of ordinary skill in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit this invention.

Please refer to Fig. 1, Fig. 2 and Fig. 3, the technical solution adopted by the present invention is: a flow rate meter based on static weighing method, including electronic scale 1, weighing water tank 2, water distribution tank 3, high-speed cylinder 4 , air compressor 5, reversing switch 6, control box 8, steel bracket 14, connecting rod 16; High-speed cylinder 4 is provided with two high-speed cylinder inlet and outlet ports, respectively head inlet and outlet 150 and tail inlet and outlet 151, called The upper part of the heavy water tank 2 is provided with a weighing water tank water inlet 10; the outer wall of the weighing water tank 2 is provided with a third drain port 12, which is used to drain outward when the water body of the weighing water tank 2 reaches a certain amount; the bottom of the weighing water tank 2 is provided with The fourth drain port 13 is used to drain water outwards when the weighing water tank is overhauled; the sub-water tank 3 is a double-layer three-cavity structure, and the return chute 19 and the slide block 18 that fits with the chute will be connected to the water tank 3 inside. The water distribution tank 3 is divided into upper and lower layers, and a partition plate 20 is arranged in the middle of the lower layer of the water distribution tank 3, and the lower layer of the water distribution tank 3 is separated into independent left and right chambers, and the lower part of the left chamber is provided with a first drain port 110, The lower part of the right chamber is provided with a second drain port 111, which is connected to the water inlet 10 of the weighing water tank through a pipe; Slide left and right in 19; the weighing water tank 2 is placed on the electronic scale 1, and does not come into mechanical contact with any other device, and is located in the inner cavity of the steel bracket 14; the water distribution tank 3, the high-speed cylinder 4, the reversing switch 6, and the air compressor 5 are installed on the upper beam of the steel bracket 14 in sequence; the piston rod of the high-speed cylinder 4 is fixedly connected with the slider 18 through the connecting rod 16, the air compressor 5 is connected with the reversing switch 6 through the air pipe 7, and the reversing switch 6 is respectively connected through the air pipe 7 It is connected with two high-speed cylinder inlet and outlet ports; when the air compressor 5 supplies air to the head of the high-speed cylinder 4 through the air pipe 7 from the head inlet and outlet outlet 150, it drives the connecting rod 16 to push the slide plate 18 in the water distribution tank 3 in the chute 19 to Slide to the left to open the right chamber and close the left chamber, and fill water into the weighing water tank 2 through the second drain port 111 and the water inlet 10 of the heavy water tank; Air is added to the tail, thereby driving the connecting rod 16 to push the slide plate 18 in the water distribution tank 3 to slide to the right in the chute 19, the left chamber can be opened and the right chamber can be closed, and the water flow can be drained outward through the first drain port 110; The control box 8 is respectively connected with the electronic scale 1, the high-speed cylinder 4 and the reversing switch 6 through the signal line 9, and the control box 8 controls the reversing switch 6 to operate the direction of cylinder air supply and the action of the high-speed cylinder 4, and automatically collects all data, Automatically analyze the data and calculate the flow rate; the data include: the time when the connecting rod 16 moves to the right, the time when the connecting rod 16 stays, the time when the connecting rod 16 moves to the left, and the weight of the water body.

The high-speed cylinder 4 of this embodiment is fixedly installed on the upper beam of the steel bracket 14 through an adjustable fixed support 17, and its piston rod and connecting rod 16 are on the same axis; twenty one. The high-speed cylinder 4 is fixed by an adjustable fixed support 17, and the position of the cylinder can be fine-tuned so that the piston rod and the connecting rod 16 of the high-speed cylinder 4 remain on the same axis. Connecting rod 16 is equipped with sealing ring 21 at the inlet of water distribution tank 3 to prevent water flow from leaking. The whole water distribution tank is connected by slotted holes, and the interface is coated with sealing material.

The control box 8 of this embodiment controls the reversing switch 6 to operate the high-speed cylinder 4 to replenish air direction and the action of the high-speed cylinder 4 through the signal line. When the water inlet 10 of the weighing water tank is fully opened, the control box 8 starts to count the time. After a certain period of time, the control box 8 transmits an instruction to the reversing switch 6 to change the air supply direction of the high-speed cylinder 4, so that the high-speed cylinder 4 pushes the slider 18 Close the right chamber, and now the control box 8 stops timing. Simultaneously control box 8 also will record the time that high-speed cylinder 4 moves left and right. The electronic scale 1 measures the weight of the water body flowing in during this time period, and feeds back the signal to the control box 8, which analyzes and calculates the flow rate. When the water body of the weighing water tank 2 reaches a certain amount, it is drained by the third drain port 12, and when the weighing water tank needs to be drained for maintenance, it is drained by the fourth drain port 13 again.

The water distribution tank 3 of this embodiment is coordinated by the high-speed cylinder 4 to complete the water flow switching, and the switching can be completed within 0.1s at the shortest, and the total time for flowing into the weighing water tank 2 can be accurately obtained.

Figure 4 shows the principle of flow measurement. The size of the slider of the sub-water tank (300×300mm) is larger than the size of the water outlet (250×250mm). When the inlet of the weighing water tank is opened, when the slider moves backward 25mm to the edge of the outlet, the inlet of the weighing water tank is still closed. When reaching the other edge (275mm), the inlet of the weighing water tank is fully open. Therefore, the actual opening and closing stroke is 25-275mm. It can be seen from the orifice outflow formula that the flow rate is proportional to the area of the water outlet, that is, proportional to the cylinder movement stroke. The cylinder starts and ends its motion at its slowest speed. Assuming that the slider opens at t ₁ , closes at t ₂ , and stays at t ₃ , the mass of the water body is M, and the flow formula is:

In actual operation, t ₃ is about 60s, t ₁ and t ₂ are generally between 0.1 and 0.5s, and the time for opening and closing the water inlet of the actual weighing water tank (stroke 25-275mm) is shorter, roughly 0.06 to 0.3 within s. Considering the opening and closing time, the average method can make the time measurement accuracy controlled within 2‰. The precision of the electronic scale is controlled within 0.5‰, and the overall precision of the device is within 2.5‰.

Figure 5 shows the calibration results of the electromagnetic flowmeter using this practical type. The electromagnetic flowmeter has not been used for a long time, and the installation environment does not fully meet the installation standards. Using the calibration instrument can correct the AD transformation parameters of the electromagnetic flowmeter, thereby correcting the drift of the sensor.

Although this manual uses a lot of electronic scales 1, weighing water tank 2, water distribution tank 3, high-speed cylinder 4, air compressor 5, reversing switch 6, air pipe 7, control box 8, signal line 9, weighing water tank inlet Nozzle 10, first drain port 110, second drain port 110, third drain port 12, fourth drain port 13, steel bracket 14, head air inlet and outlet 150, tail air inlet and outlet 151, connecting rod 16, cylinder fixing support 17, sliding plate 18, chute 19, partition plate 20 and sealing ring 21 and other terms, but the possibility of using other terms is not excluded. These terms are only used to describe the essence of the present invention more conveniently, and it is against the spirit of the present invention to interpret them as any additional limitation.

It should be understood that the parts not described in detail in this specification belong to the prior art.

It should be understood that the above-mentioned descriptions for the preferred embodiments are relatively detailed, and should not therefore be considered as limiting the scope of the patent protection of the present invention. Within the scope of protection, replacements or modifications can also be made, all of which fall within the protection scope of the present invention, and the scope of protection of the present invention should be based on the appended claims.

Claims (5)

1. a kind of flow calibration instrument based on static weighing method, it is characterised in that：Including electronic scale（1）, water tank of weighing（2）, point Water tank（3）, high speed cylinder（4）, air compressor machine（5）, reversing switch（6）, control chamber（8）, steel bracket（14）, connecting rod（16）；

Described high speed cylinder（4）On be provided with two high speed cylinder air inlet/outlets, respectively head air inlet/outlet（150）And tail Portion's air inlet/outlet（151）, described water tank of weighing（2）Top is provided with water tank inlet of weighing（10）；

Described diversion box（3）Construct for double-deck three chamber, its internal reversion chute by arranging（19）And agree with chute Slide block（18）By described diversion box（3）It is separated into upper and lower two-layer, described diversion box（3）Lower floor's middle setting have dividing plate （20）, by described diversion box（3）Lower floor is separated into independent left chamber and right chamber room, and described left chamber bottom is provided with One discharge outlet（110）, right chamber lower portion be provided with the second discharge outlet（111）, described the second discharge outlet（111）By pipeline with Described water tank inlet of weighing（10）Connection；Described slide block（18）Bottom surface and described dividing plate（20）Upper top surface laminating, And can be in described reversion chute（19）Inside horizontally slip；

Described water tank of weighing（2）It is positioned over described electronic scale（1）On, and do not contact with other any devices generation mechanics, Positioned at described steel bracket（14）In inner chamber；Described diversion box（3）, high speed cylinder（4）, reversing switch（6）, air compressor machine（5） Order is arranged on described steel bracket（14）On upper beam；Described high speed cylinder（4）Piston rod pass through described connecting rod（16） With described slide block（18）It is fixedly connected, described air compressor machine（5）By trachea（7）With described reversing switch（6）Connection, institute The reversing switch stated（6）By trachea（7）It is connected with two described high speed cylinder air inlet/outlets respectively；When described air compressor machine （5）By trachea（7）From head air inlet/outlet（150）To high speed cylinder（4）Head QI invigorating, so as to drive described connecting rod（16） Promote diversion box（3）Interior slide plate（18）In chute（19）In slide to the left, you can open right chamber room and close left chamber and simultaneously pass through The second described discharge outlet（111）With heavy-water tank water inlet（10）To described water tank of weighing（2）Water filling；Described air compressor machine （5）By trachea（7）From afterbody air inlet/outlet（151）To high speed cylinder（4）Afterbody QI invigorating, so as to drive described connecting rod（16） Promote diversion box（3）Interior slide plate（18）In chute（19）In slide to the right, you can open left chamber and close right chamber room and simultaneously pass through The first described discharge outlet（110）Outwards drain current；

Described control chamber（8）By holding wire（9）Respectively with described electronic scale（1）, high speed cylinder（4）And reversing switch （6）Connection, described control chamber（8）The described reversing switch of control（6）Operation cylinder QI invigorating direction, and high speed cylinder（4） Action, and all data of automatic data collection, automatically analyze data and calculate outflow.

2. the flow calibration instrument based on static weighing method according to claim 1, it is characterised in that：Described packet Include：Connecting rod（16）Move right time, connecting rod（16）The time of staying, connecting rod（16）Movement time, water body weight to the left.

3. the flow calibration instrument based on static weighing method according to claim 1, it is characterised in that：Described high speed cylinder （4）By adjustable hold-down support（17）It is fixedly mounted on described steel bracket（14）On upper beam, its piston rod and connecting rod （16）In same axis.

4. the flow calibration instrument based on static weighing method according to claim 1, it is characterised in that：Described connecting rod（16） Through described diversion box（3）Sealing ring is provided with the outer wall of upper strata（21）.

5. the flow calibration instrument based on static weighing method according to claim 1, it is characterised in that：Described water tank of weighing （2）Outer wall is provided with the 3rd discharge outlet（12）, for when water tank of weighing（2）Water body outside draining when reaching a certain amount of；It is described Water tank of weighing（2）Bottom is provided with the 4th discharge outlet（13）, for water is outwards drained when water tank is weighed in maintenance.