CN104101387B - The adaptive flute type manage-style flowmeter of adjustable type - Google Patents

Abstract

The invention discloses an adjustable self-adaptive flute-shaped pipe air volume measuring instrument, which includes: a pressure transmission pipe, which has a pressure outlet pipe on the full pressure side and a pressure outlet pipe on the static pressure side, and the pressure outlet pipes on the full pressure side and the static pressure side are respectively There are multiple full and static pressure connection pipe heads; the measuring point sampling bracket is connected to one side of the pressure transmission pipe. There are multiple detachable pressure sampling heads on the measuring point sampling bracket, and each pressure sampling head consists of Correspondingly set full-pressure sampling element and static pressure sampling element are composed. Both ends of the full-pressure sampling element have a full-pressure pressure outlet tube head and a full-pressure sampling hole. The full-pressure sampling hole is connected with the full-pressure pressure outlet tube head. The two ends of the element respectively have a static pressure lead-out pipe head and a static pressure sampling hole, the static pressure sampling hole communicates with the static pressure lead-out pipe head, and the total pressure pressure lead-out pipe head is respectively sealed and connected with the said total pressure pressure connection pipe head, The static pressure outlet pipe heads are sealedly connected with the static pressure connection pipe heads respectively.

Description

Adjustable self-adaptive flute-type pipe air volume measuring instrument

technical field

The invention relates to an adjustable self-adaptive flute-shaped pipe air volume measuring instrument.

Background technique

Combustion adjustment is one of the core technologies of thermal power generation, and the proportional control of fuel and air volume is an important means of combustion adjustment. Therefore, the measurement means and accuracy of fuel volume and air volume are particularly important. In modern large-scale thermal power plants, there are many types and styles of air flow measurement components, but most of them are designed and used by utilizing the energy conservation and fluid continuity principles of fluid mechanics. Due to the inhomogeneity of the flow field in the air duct of the actual power plant, after the air flow measuring element is installed, it needs to be calibrated with the speed measuring element, and the correct air flow value can only be displayed after the calibration coefficient is obtained.

Hot-wire anemometer, Pitot tube, back tube, flute tube and other speed measuring components are commonly used calibration components. The flute-shaped pipe adopts the equal cross-sectional area method to arrange the measuring points, and can measure the dynamic pressure of multiple positions on the cross-section at one time. The measurement is convenient and accurate, so it is widely used in the measurement of circular cross-section pipes. Coal-fired thermal power stations, especially the environmental protection and energy-saving circulating fluidized bed boiler power stations that the country is vigorously developing at present, because there are many circular air ducts in its structure, the combustion air distribution needs to calibrate its flow measurement components, and the flute tube is due to the Its advantages in the measurement of circular ducts have been widely used.

The piccolo is a non-standard speed measuring device installed in the pipeline to measure the average flow velocity of the airflow at one time. Figure 1 shows a schematic diagram of the structure of the related double piccolo. As shown in Figure 1, the double flute tube passes through the pipeline G, and the double flute tube includes a full-pressure side pressure outlet pipe 1' and a static pressure side pressure outlet pipe 2', and the full-pressure side pressure outlet pipe 1' and static side The pressure side pressure lead-out pipe 2' is assembled together, a row of total pressure measuring holes 1a' is opened on the upstream surface of the total pressure side pressure lead-out pipe 1', and a row of static pressure measuring holes is opened on the back of the static pressure side pressure lead-out pipe 2'. The hole 2a', the total pressure measuring hole 1a' and the static pressure measuring hole 2a' are all located in the pipe G.

The flute tube is a non-standard measuring element used for the measurement of the air velocity in the pipe. Before the flute tube is used for measurement, the standard Pitot tube should be used to calibrate its velocity coefficient.

The velocity coefficient of the standard tachometer k≈1.0, and the velocity coefficient of the flute tube is calibrated by the standard Pitot tube.

In the formula: P _d.pit — dynamic pressure measured by standard Pitot tube, Pa

P _d - the dynamic pressure measured by the calibration element flute tube, Pa

According to the different pipe diameters, determine the number of flute pipe measuring points, and use the equal section method to determine the position of the measuring points. The following table 1 illustrates the determination of the number of measuring points of the circular cross-section pipeline equal-section method.

Table 1

As shown in Figure 2, the distance between each measuring point and the center of the circular section is calculated as follows:

In the formula:

r _i ——the distance from the measuring point to the center of the circular section

R——circular section radius (inner diameter)

i——The serial number of the measuring point counted from the center of the circular section

N——Number of equal-area rings that need to be divided into circular sections

The above-mentioned related piccolo has the following disadvantages:

(1) Due to the wide variety of specifications of wind pipes in power plants, for pipes with different pipe diameters, the number of measuring points, the location of measuring points and the length of flute pipes are different when measuring with flute pipes. Therefore, in order to meet the calibration requirements of various pipe diameters, it is necessary to process many sets of flute-shaped pipes of different specifications. The production cost is high, the utilization rate is low, and there is no reusable value, resulting in a waste of funds and raw materials.

(2) Since the flute-shaped pipe is a measuring instrument that runs through the entire cross-section, it needs to be carefully calculated and designed for each type of pipe, and the thickness of the pipe wall, connection method, etc. need to be considered. Since the current flute-shaped pipe cannot be changed after it is manufactured, in A slight deviation between design and manufacturing can result in obsolete components that are unusable, wasting money and raw materials. This happens from time to time.

(3) The design starting point of most measuring components is the integration of pressure sampling points and pressure transmission tubes, such as backrest tubes, flute tubes, etc. Therefore, once these components are finished, they cannot be changed. Once the design deviates Or if the size of the measuring air duct changes, the original measuring element will not be used, resulting in great waste; in addition, for a specific size of air duct, the corresponding flute-shaped tube must be customized, and the production cost is expensive due to the small production volume.

Contents of the invention

The purpose of the present invention is to provide an adjustable self-adaptive flute-shaped pipe air volume measuring instrument, which can meet the air volume calibration of various specifications of pipe diameters, greatly saves production costs, can be used repeatedly, and improves the utilization rate of equipment.

Above-mentioned purpose of the present invention can adopt following technical scheme to realize:

An adjustable self-adaptive flute-type pipe air flow measuring instrument, the air flow measuring instrument includes: a pressure transmission pipe, which has a full pressure side pressure outlet pipe and a static pressure side pressure outlet pipe connected together, the total pressure side The pressure outlet pipe is provided with a plurality of full-pressure pressure connection nozzles, and the static pressure side pressure outlet pipe is provided with a plurality of static pressure connection nozzles; the measuring point sampling bracket is connected to one side of the pressure transmission pipe, and the There are multiple detachable pressure sampling heads on the measuring point sampling bracket. Each pressure sampling head is composed of a corresponding full-pressure sampling element and a static pressure sampling element. One end of the full-pressure sampling element has a full-pressure pressure outlet tube. The other end of the full-pressure sampling element has a full-pressure sampling hole, and the full-pressure sampling hole communicates with the full-pressure pressure outlet head. One end of the static pressure sampling element has a static pressure outlet head. The other end of the static pressure sampling element One end has a static pressure sampling hole, the static pressure sampling hole communicates with the static pressure outlet pipe head, and the total pressure pressure outlet pipe head is respectively sealed and connected with the total pressure pressure connection pipe head, and the static pressure pressure outlet pipe head is respectively It is tightly connected with the static pressure connection pipe head.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument described above, the measuring point sampling support is provided with a scale.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument described above, the full pressure pressure lead-out pipe head and the full pressure pressure connection pipe head are connected flexibly.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument described above, the full pressure pressure outlet pipe head and the full pressure pressure connection pipe head are connected by a rubber tube.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument described above, the full pressure pressure outlet pipe head and the full pressure pressure connection pipe head are rigidly connected.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument described above, the static pressure outlet pipe head and the static pressure connection pipe head are connected flexibly.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument as described above, the static pressure outlet pipe head and the static pressure connection pipe head are connected by a rubber tube.

According to the adjustable self-adaptive flute-shaped pipe air volume measuring instrument described above, the static pressure outlet pipe head and the static pressure connection pipe head are rigidly connected.

The characteristics and advantages of the adjustable self-adaptive flute-type pipe air volume measuring instrument of the present invention are:

1. It separates the pressure sampling point from the pressure transmission pipe, so that it can be used for air volume measurement and component calibration of various specifications of pipes, which greatly saves production costs;

2. There is no need to customize flute-shaped pipes for pipes of various diameters, which can realize standardization and mass production, save a lot of costs and improve equipment utilization;

3. The design is more concise, and there is no need to consider many details, and there will be no situation where the equipment cannot be used due to incomplete consideration of the on-site environment;

4. It can be used repeatedly, and can also be used for flow measurement of various air ducts.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of relevant double flute;

Fig. 2 is a schematic diagram of using the circular section method to calculate the distance between each measuring point and the center of the circular section;

Fig. 3 is a schematic structural view of the air volume measuring instrument of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in FIG. 3 , the adjustable self-adaptive flute-shaped pipe air volume measuring instrument proposed by the embodiment of the present invention includes a pressure transmission pipe and a sampling support 1 at a measuring point. The pressure transmission pipe has a total pressure side pressure outlet pipe 2 and a static pressure side pressure outlet pipe 3 connected together. The total pressure side pressure outlet pipe 2 is provided with a plurality of total pressure pressure connection pipe heads 2a. The pressure-side pressure lead-out pipe 3 is provided with a plurality of static pressure connection pipe heads 3a. The measuring point sampling support 1 is connected to one side of the pressure transmission pipe, and the measuring point sampling support 1 is provided with a plurality of detachable pressure sampling heads 4, and each pressure sampling head 4 is provided with a corresponding full pressure sampling element It is composed of a static pressure sampling element, one end of the full pressure sampling element has a full pressure pressure outlet pipe head 5a, the other end of the full pressure sampling element has a full pressure sampling hole 5b, and the full pressure sampling hole 5b is connected with the full pressure pressure outlet pipe head 5a communicates, and one end of the static pressure sampling element has a static pressure outlet nozzle 6a, and the other end of the static pressure sampling element has a static pressure sampling hole 6b, and the static pressure sampling hole 6b communicates with the static pressure outlet nozzle 6a, so The total pressure outlet nozzles 5a are sealed in connection with the total pressure connection nozzles 2a, and the static pressure outlet nozzles 6a are respectively sealed in connection with the static pressure connection nozzles 3a.

Specifically, the full-pressure side pressure lead-out pipe 2 is provided with a plurality of holes, and a full-pressure pressure connection pipe head 2a is installed on each hole; the static-pressure side pressure lead-out pipe 3 is provided with a plurality of holes, each A static pressure connection pipe head 3a is installed on the hole.

The number and position of the pressure sampling heads 4 can be determined according to the specification of the measuring pipe diameter.

When this embodiment is in use, arrange the pressure sampling heads 4 according to the calculated number and position, connect the full-pressure pressure outlet pipe head 1b of the pressure sampling head 4 with the full-pressure pressure connection pipe head 2a, and the static pressure pressure outlet pipe The head 6a is connected to the static pressure connection pipe head 3a, and an instrument for reading pressure such as a micromanometer is connected to the pressure outlet pipe 2 of the total pressure side and the pressure outlet pipe 3 of the static pressure side respectively; In the wind measuring duct, the side of the pressure sampling head 4 with the full pressure sampling element (i.e. the full pressure side) is facing the direction of the incoming flow, and the side with the static pressure sampling element (i.e. the static pressure side) is facing away from the direction of the incoming flow. The wind in the wind measuring duct is drawn from the full pressure sampling hole 5b (or static pressure sampling hole 6b) through the full pressure pressure outlet pipe head 5a (or static pressure pressure outlet pipe head 6a) and the full pressure pressure connection pipe head 2a (or static pressure pressure outlet pipe head 6a). Connect the pipe head 3a) into the pressure outlet pipe 2 of the full pressure side (or the pressure outlet pipe 3 of the static pressure side), read the pressure difference through the micromanometer reading instrument, and calculate the wind speed after recording.

The pressure sampling head 4 of this embodiment is detachable. For example, a nut (or other connection method) can be used to connect the pressure sampling head 4 to the sampling support 1, so that the pressure sampling point 1a can be moved, and the sampling point and the pressure outlet pipe Separated, so as to meet the needs of measurement and calibration of different pipe diameters, greatly save production costs, and can be reused to improve equipment utilization.

There are multiple pressure sampling points 1a on the sampling support 1, one is to meet the needs of multiple measuring points, and the other is to choose the connection between the nearest pipe head and the outlet pipe during use.

According to an embodiment of the present invention, scales are provided on the measuring point sampling support 1 so as to quickly install the pressure sampling head 4 on the corresponding position of the sampling support 1 .

The full-pressure pressure lead-out pipe head 5a and the full-pressure pressure connection pipe head 2a may be flexibly connected, for example, the full-pressure pressure lead-out pipe head 5a and the full-pressure pressure connection pipe head 2a are connected through rubber tube connection. In addition, the full-pressure pressure outlet pipe head 5a and the full-pressure pressure connection pipe head 2a may also be rigidly connected, for example, the connection between the full-pressure pressure outlet pipe head 5a and the full-pressure pressure connection pipe head 2a They are connected by a threaded sampling connection tube.

Similarly, the static pressure outlet pipe head 6a and the static pressure connection pipe head 3a may be flexibly connected, for example, the connection between the static pressure outlet pipe head 6a and the static pressure connection pipe head 3a are connected by rubber tubes. In addition, the static pressure outlet pipe head 6a and the static pressure connection pipe head 3a may also be rigidly connected, for example, the connection between the static pressure outlet pipe head 6a and the static pressure connection pipe head 3a They are connected by a threaded sampling connection tube.

The above descriptions are only a few embodiments of the present invention, and those skilled in the art can make various changes, modifications or combinations to the embodiments of the present invention according to the disclosure of the application documents without departing from the spirit and scope of the present invention.

Claims (8)

1. An adjustable self-adaptive flute-type pipe air flow measuring instrument, characterized in that, the air flow measuring instrument comprises: The pressure transmission pipe has a total pressure side pressure outlet pipe and a static pressure side pressure outlet pipe connected together. The pipe is provided with multiple static pressure connection pipe heads; The measuring point sampling bracket is connected to one side of the pressure transmission pipe. The measuring point sampling bracket is provided with a plurality of detachable pressure sampling heads, and each pressure sampling head is composed of a corresponding full pressure sampling element and static pressure sampling One end of the full-pressure sampling element has a full-pressure pressure outlet tube head, and the other end of the full-pressure sampling element has a full-pressure sampling hole. The full-pressure sampling hole is connected with the full-pressure pressure outlet tube head. The static pressure sampling One end of the element has a static pressure outlet pipe head, the other end of the static pressure sampling element has a static pressure sampling hole, the static pressure sampling hole communicates with the static pressure outlet pipe head, and the total pressure pressure outlet pipe head is connected to the full pressure outlet pipe head respectively. The pressure connection pipe head is in sealing connection, and the static pressure outlet pipe head is respectively in sealing connection with the static pressure connection pipe head. 2. The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 1, wherein a scale is provided on the measuring point sampling support. 3 . The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 1 , characterized in that, the full-pressure pressure lead-out pipe head and the full-pressure pressure connection pipe head are flexibly connected. 4 . 4. The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 3, characterized in that, the full-pressure pressure lead-out pipe head and the full-pressure pressure connection pipe head are connected by a rubber tube. 5 . The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 1 , characterized in that, the full-pressure pressure outlet pipe head and the full-pressure pressure connection pipe head are rigidly connected. 6 . 6. The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 1, characterized in that the static pressure outlet pipe head and the static pressure connection pipe head are connected flexibly. 7. The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 2, characterized in that the static pressure outlet pipe head and the static pressure connection pipe head are connected by a rubber tube. 8. The adjustable self-adaptive flute-shaped pipe air volume measuring instrument according to claim 1, characterized in that the static pressure outlet pipe head and the static pressure connection pipe head are rigidly connected.