CN206772360U - A kind of wing mean velocity tube flowmeter - Google Patents

Abstract

The utility model discloses a kind of wing mean velocity tube flowmeter, including measuring pipeline, pressure measuring valve and blowoff valve, streamlined even speed tube is provided with the measurement pipeline, offer that malleation collects hole and negative pressure collects hole in the streamlined even speed tube, meeting for the streamlined even speed tube offers five groups of positive pressure sensing holes on stream end face, length direction of five groups of positive pressure sensing holes along the streamlined even speed tube is distributed in log-linear, five groups of negative pressure sensing holes are offered on the two sides of the streamlined even speed tube, length direction of the pressure sensing hole along streamlined average rate tube body is born described in five groups to be distributed in log-linear, the determination of this principle is tried to achieve by log-linear measurement, log-linear measurement proves according to experiment, its error is no better than zero, therefore its measurement accuracy is higher.

Description

A kind of wing mean velocity tube flowmeter

Technical field

It the utility model is related to a kind of wing mean velocity tube flowmeter.

Background technology

Wing mean velocity tube flowmeter is mainly used in the flow measurement of air quantity system in large scale industry pipeline, because fluid exists Velocity flow profile in pipeline is：Flow velocity at most slow, the close pipeline center of flow velocity at tube wall is most fast, in general air measuring Device is the flow velocity for measuring single-point in pipeline, so as to calculate the flow in pipeline, due to the inhomogeneities of flow velocity in pipeline, So single-point flow velocity can not embody the true flow condition in pipeline, as shown in figure 1, the flow velocity in pipeline is curved arrangement , i.e. center flow velocity highest is minimum along tube wall flow velocity, when entering and popping one's head in built in pipeline, because flow velocity is different, so each point sense The pressure received is also that different, conventional measurement apparatus are that pressure sensing hole is averagely opened on probe or measures single point pressure, The pressure so measured is extremely inaccurate, so as to bring the inaccurate result of measurement.

Additionally, due to the general pressure of air quantity system is relatively low, flow is small, so as to cause signal small, this brings to normal measurement Very big difficulty.

Utility model content

The purpose of this utility model is to overcome defect present in prior art, there is provided a kind of measurement accuracy is high, signal Strong wing mean velocity tube flowmeter.

To achieve the above object, the technical solution of the utility model there is provided a kind of wing mean velocity tube flowmeter, including Measurement pipeline, with measurement the pipeline pressure measuring valve and blowoff valve that are connected, it is described to measure pipeline interior edge it has been radially arranged Streamlined even speed tube, offers that malleation collects hole and negative pressure collects in the streamlined even speed tube respectively along its length Hole, meeting for the streamlined even speed tube offer the five groups of positive pressure sensing holes for collecting hole with the malleation and being connected on stream end face, and five Length direction of the positive pressure sensing hole of group along the streamlined even speed tube is distributed in log-linear, the position of positive pressure sensing hole described in five groups Be followed successively by 0.277R, 0.566R, 0.695R, 0.847R, 0.962R, offered on the two sides of the streamlined even speed tube with The negative pressure collects five groups of negative pressure sensing holes that hole is connected, and length of the pressure sensing hole along streamlined average rate tube body is born described in five groups Direction is distributed in log-linear, bear described in each five groups of both sides pressure sensing hole position be followed successively by 0.277R, 0.566R, 0.695R ,= 0.847R, 0.962R, wherein R are the radius of measurement pipeline.

It is further improved to be：The both sides of the streamlined even speed tube are symmetrically arranged with wing flow deflector.

It is further improved to be：The wing flow deflector is obliquely installed.

It is further improved to be：The pressure measuring valve is vertically connected at the top of the measurement pipeline, and the blowoff valve is vertical It is connected to the lower section of the measurement pipeline.

The advantages of the utility model and beneficial effect are：

1st, the flow velocity measured in pipeline is divided into 5 mean flow rate faces, and the determination of this principle is asked by log-linear measurement , log-linear measurement according to it is demonstrated experimentally that its error no better than zero, therefore its measurement accuracy is higher；

2nd, streamlined average rate tube body type shape meets principle of hydrodynamics, and convection body can carry out self-rectifying effect；

3rd, the effect of wing flow deflector flows through a fluid stream of streamlined average rate tube body and obtains rectification, and makes suction side Fluid increases due to the contraction of flow area, so that suction side pressure reduces, so that the survey of wing mean velocity tube flowmeter Amount differential pressure is exaggerated, and is improved measurement accuracy.

Brief description of the drawings

Fig. 1 is the schematic diagram of prior art；

Fig. 2 is schematic diagram of the present utility model；

Fig. 3 is Fig. 2 schematic cross-section.

Wherein：1st, pipeline is measured；2nd, pressure measuring valve；3rd, streamlined even speed tube；4th, wing flow deflector；5th, blowoff valve；6th, malleation Collect hole；7th, negative pressure collects hole.

Embodiment

With reference to the accompanying drawings and examples, specific embodiment of the present utility model is further described.Implement below Example is only used for clearly illustrating the technical solution of the utility model, and can not limit protection model of the present utility model with this Enclose.

As shown in Figure 2 and Figure 3, wing mean velocity tube flowmeter, including measure pipeline 1, measure what pipeline 1 was connected with described Pressure measuring valve 2 and blowoff valve 5, measurement pipeline 1 interior edge its be radially arranged streamlined even speed tube 3, the streamlined average rate Offer that malleation collects hole 6 and negative pressure collects hole 7 in pipe 3 respectively along its length, the streamlined even speed tube 3 meets stream Offer the five groups of positive pressure sensing holes for collecting hole 6 with the malleation and being connected on end face, five groups of positive pressure sensing holes are along the streamlined The length direction of even speed tube 3 in log-linear be distributed, the position of positive pressure sensing hole described in five groups be followed successively by 0.277R, 0.566R, 0.695R, 0.847R, 0.962R, offer on the two sides of the streamlined even speed tube 3 and collect hole 7 with the negative pressure and be connected The negative pressure sensing hole of logical five groups, length direction of the pressure sensing hole along the body of streamlined even speed tube 3 is born described in five groups in log-linear point Cloth, the position of negative pressure sensing hole is followed successively by 0.277R, 0.566R, 0.695R ,=0.847R, 0.962R described in each five groups of both sides, wherein R is the radius of measurement pipeline 1.

Streamlined equalizer flow tube is met into principle of hydrodynamics using streamline shape, and convection body can carry out self-rectifying work With.

In order to further improve rectification effect, the both sides of the streamlined even speed tube 3 are symmetrically arranged with wing flow deflector 4, Further preferred scheme is：The wing flow deflector 4 is obliquely installed, then flow through streamlined even speed tube 3 a fluid stream obtain it is whole Stream, and the fluid of suction side is increased due to the contraction of flow area, so that suction side pressure reduces, so that wing The measurement differential pressure of even speed tube apparatus for measuring air quantity is exaggerated, and is improved measurement accuracy.

Preferred embodiment is in the present embodiment, and the pressure measuring valve 2 is vertically connected at the top of the measurement pipeline 1, The blowoff valve 5 is vertically connected at the lower section of the measurement pipeline 1.

Described above is only preferred embodiment of the present utility model, it is noted that for the common skill of the art For art personnel, on the premise of the utility model technical principle is not departed from, some improvements and modifications can also be made, these change Enter and retouch and also should be regarded as the scope of protection of the utility model.

Claims (4)

1. a kind of wing mean velocity tube flowmeter, including measure pipeline, the pressure measuring valve being connected with the measurement pipeline and blowdown Valve, it is characterised in that:It has been radially arranged streamlined even speed tube to the measurement pipeline interior edge, the streamlined even speed tube interior edge its The malleation that length direction offers respectively collects hole and negative pressure collects hole, and meeting for the streamlined even speed tube offers on stream end face Collect five groups of positive pressure sensing holes that hole is connected, length side of five groups of positive pressure sensing holes along the streamlined even speed tube with the malleation Be distributed in log-linear, the position of positive pressure sensing hole described in five groups be followed successively by 0.277R, 0.566R, 0.695R, 0.847R, 0.962R, the five groups of negative pressure-sensitive for collecting hole with the negative pressure and being connected are offered on the two sides of the streamlined even speed tube Hole, length direction of the pressure sensing hole along streamlined average rate tube body is born described in five groups and is distributed in log-linear, each five groups of institutes in both sides The position for stating negative pressure sensing hole is followed successively by 0.277R, 0.566R, 0.695R ,=0.847R, 0.962R, and wherein R is the half of measurement pipeline Footpath.

2. wing mean velocity tube flowmeter as claimed in claim 1, it is characterised in that：The both sides of the streamlined even speed tube are symmetrical It is provided with wing flow deflector.

3. wing mean velocity tube flowmeter as claimed in claim 1, it is characterised in that：The wing flow deflector is obliquely installed.

4. wing mean velocity tube flowmeter as claimed in claim 1, it is characterised in that：The pressure measuring valve is vertically connected at the survey The top in buret road, the blowoff valve are vertically connected at the lower section of the measurement pipeline.