CN207379563U - A gas flow measuring device - Google Patents

Abstract

The utility model is related to a kind of gas flow surveying instrument, by the symmetrical round-meshed flow conditioner installed at 10 times of caliber distances after at pipe-line direction change and followed by 10 times of caliber distances, the ultrasonic flowmeter of installation is formed.Port edge at the fluid passageway incoming of symmetrical round-meshed flow conditioner is designed as round shape or arc curve (2).Symmetrical round-meshed flow conditioner using flange form installation by the way of or punched-type installation mode.Symmetrical round-meshed flow conditioner at pipe-line direction change between ultrasonic flowmeter is installed, most short rectification flow development length before ultrasonic flowmeter is greatly shortened, and makes measurement accuracy higher.The runner port of symmetrical round-meshed flow conditioner round shape or arc curve, then can reduce the generation of high-frequency noise.Two kinds of mounting means of symmetrical round-meshed flow conditioner can flexibly be selected according to topographic features.

Description

A gas flow measuring device

technical field

The utility model relates to the field of gas flow measurement, in particular to a gas flow measurement device which is used in combination with an ultrasonic flowmeter and a flow regulator with symmetrically distributed round holes.

Background technique

The equipment used for gas flow measurement is a volumetric flowmeter. Commonly used volumetric flowmeters include ultrasonic flowmeters, turbine flowmeters, orifice flowmeters, gas vortex flowmeters, and Venturi nozzle flowmeters. At present, most of the stations along several large gas pipelines in China use ultrasonic flowmeters.

Disturbance elements affect measurement accuracy: The accuracy of ultrasonic flowmeter volume measurement is easily affected by the installation effect. The so-called installation effect is the non-ideal distribution of the flow field in the pipeline due to the change of the pipeline line, resulting in measurement deviation. For ultrasonic flowmeters, relatively accurate measurement results can be obtained when the fluid flow rate reaches a fully developed state, but in actual application conditions, due to the existence of installation effects, it is difficult to achieve ideal measurement accuracy.

Noise affects measurement accuracy: the working principle of gas ultrasonic flowmeter is to measure the flow rate by using the propagation time difference method, that is, to use the ultrasonic transducer to alternately send and receive ultrasonic pulses in opposite directions, and to indirectly measure the flow rate by detecting and calculating the propagation time difference between the forward and reverse flow of the pulse in the natural gas medium. Measure the flow rate of natural gas, and then calculate the flow rate of natural gas through the flow rate. Therefore, in order to obtain the forward and reverse flow propagation time of natural gas respectively, it is required that the receiving transducer of the flowmeter can correctly detect the ultrasonic pulse emitted by the transmitting transducer. Ultrasound is a frequency band with a frequency higher than 20kHz, which may cause the transducer detection unit to be unable to correctly distinguish the working pulse signal and noise, thereby affecting the measurement accuracy of the flowmeter.

Contents of the invention

The problem to be solved by the utility model is to propose a gas flow measurement device with simple structure, reliable performance, convenient on-site installation and improved measurement accuracy of the ultrasonic flowmeter for the shortcomings of the existing ultrasonic flowmeter used in natural gas pipelines.

In order to achieve the above object, the utility model adopts the following technical solutions:

Install a flow regulator with symmetrically distributed circular holes at a distance of 10 times the pipe diameter after the direction of the pipeline line changes, and then install an ultrasonic flowmeter at a distance of 10 times the pipe diameter. The edge of the port at the incoming flow of the fluid channel of the flow regulator with symmetrically distributed circular holes is designed as a circular or arc-shaped curved surface (2). The flow regulator with symmetrically distributed round holes can be installed in a flange type. This installation method is suitable for better site conditions. The pipeline can be divided into two sections, and the flow regulator with symmetrically distributed round holes can be placed in the two sections of pipeline. The case of axially fixing with bolts in the middle (3). The flow regulator with symmetrically distributed round holes can be installed in a perforated installation method. This installation method is suitable for poor site conditions. The pipeline is divided into two sections and the workload is relatively large. The case of fixing a flow conditioner with symmetrically distributed round holes (4).

The utility model has the following advantages due to the adoption of the above technical scheme:

1. Installing a flow regulator with round holes symmetrically distributed between the line direction change point and the ultrasonic flowmeter can eliminate the vortex and flow field asymmetry generated by the gas at the line direction change point, so that the fluid state on the cross section can be restored. Compared with directly measuring the volume flow of natural gas with an ultrasonic flowmeter, it has the advantages of a more stable gas flow field and higher accuracy of volume measurement, and after the pipeline line is changed, a flow regulator with symmetrically distributed round holes is installed, and the ultrasonic flow rate The length of the shortest upstream straight pipe section required before the calculation will be shortened from 42 times the pipe diameter when it is not installed to 20 times the pipe diameter.

2. The circular or arc-shaped curved surface at the port edge of the flow channel of the flow regulator with round holes symmetrically distributed can reduce the high-frequency noise generated when the fluid flows through the acute angle of the port edge of the flow channel of the general flow regulator, and further Improve the measurement accuracy of ultrasonic flowmeter.

3. The two installation methods of the flow regulator with symmetrically distributed round holes make the utility model more flexible and practical in use, and choosing different installation methods according to different terrain conditions can save workload and reduce construction difficulty.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the utility model

Fig. 2 is the front view of the flow regulator with round holes symmetrically distributed in the utility model

Fig. 3 is a schematic diagram of the arc port edge of the flow regulator with round holes symmetrically distributed in the utility model

Fig. 4 is a schematic diagram of a flanged installation of a flow regulator with round holes symmetrically distributed in the utility model

Fig. 5 is a schematic diagram of perforated installation of a flow regulator with round holes symmetrically distributed in the utility model

Among them: 1. Ultrasonic flowmeter; 2. Arc-shaped surface port edge; 3. Screw hole; 4. Bolt.

Detailed ways

The specific implementation of the present utility model is further described below in conjunction with accompanying drawing:

As shown in Figure 1, a gas flow measurement device consists of a flow regulator with round holes symmetrically distributed at a distance of 10 times the pipe diameter behind the change in the direction of the pipeline line, and an ultrasonic flow regulator installed at a distance of 10 times the pipe diameter behind. flow meter configuration. Install a flow regulator with round holes symmetrically distributed at a distance of 10 times the diameter of the pipeline after the direction of the pipeline changes, which can eliminate the vortex and asymmetry of the flow field generated by the gas at the change of the pipeline, and make the fluid on the cross section State redistribution. The circular or arc-shaped curved surface at the port edge of the flow channel of the flow regulator with round holes symmetrically distributed can reduce the high-frequency noise generated when the fluid flows through the acute angle of the port edge of the flow channel of the general flow regulator.

As shown in Figure 4, the flange installation method of the flow regulator with symmetrical distribution of round holes is suitable for better site conditions. The pipeline can be divided into two sections, and the flow regulator with symmetrical distribution of round holes is placed in the two sections. The case where the middle of the pipe is axially fixed with bolts. As shown in Figure 5, the perforated installation method of the flow regulator with round holes symmetrically distributed is suitable for poor site conditions. The pipeline is divided into two sections and the workload is large. Fixed the case of flow regulators with symmetrically distributed circular holes.

Claims (1)

1. a kind of gas flow surveying instrument, it is characterised in that：After at the pipe-line direction change at 10 times of caliber distances Symmetrical round-meshed flow conditioner is installed, ultrasonic flowmeter is installed at 10 times of caliber distances followed by；It will be symmetrical Port edge at the fluid passageway incoming of round-meshed flow conditioner is designed as round shape or arc curve (2)；It is symmetrical Round-meshed flow conditioner using flange form installation by the way of or punched-type installation mode.