CN201522501U - Boiler Primary Air Velocity Differential Pressure Measuring Device - Google Patents

Abstract

The utility model relates to a boiler primary air velocity differential pressure type measuring device, which comprises a differential pressure type measuring pipe and a signal processing unit. The differential pressure type measuring pipe penetrates into a flange, two air outlet pipes which are mutually parallel are arranged on outer walls on the same side of two pipe bodies of the differential pressure type measuring pipe located above an upper end surface of the flange, and the outer side end portions of the two air outlet pipes are directly fixedly connected with two air measuring ports of the signal processing unit. The boiler primary air velocity differential pressure type measuring device integrates functions of a measuring probe, the signal processing unit and the like, is light, convenient and small, is simple in structure, high in protection level and more convenient in mounting and using, greatly reduces construction cost, increases reliability and guarantees measurement accuracy.

Description

Boiler Primary Air Velocity Differential Pressure Measuring Device

technical field

The utility model belongs to the technical field of automatic instruments, in particular to a boiler primary wind speed differential pressure measuring device.

Background technique

At present, most of the main models of the domestic power grid are generator sets of 300MW and above, and most of the matching boilers are direct blowing boilers. technical problems. At present, people have developed a device for measuring primary wind speed. The structure of the device is shown in Figure 6: it is composed of a measuring probe installed on the pipeline, a pressure transmission tube 12 and a micro-differential pressure transmitter. Signal processing unit 2, the measuring probe includes a differential pressure measuring tube and a flange, and the differential pressure measuring tube is installed in the flange, and is located on the outer walls of the same side of the two tube bodies of the measuring tube above the upper end surface of the flange Make two parallel air outlet pipes 3, the two air outlet pipes are respectively connected to the two input ends of the signal processing unit through a pressure transmission pipe, the signal processing unit is arranged in the instrument box away from the measurement site and its The output terminal is connected to the computer. The flow rate differential pressure signal obtained by the measuring probe is transmitted to the signal processing unit through the pressure transmission tube, and the differential pressure signal is converted into a standard DC current signal of 4 ~ 20mA (or 0 ~ 10mA), and the current signal is received and calculated by the computer. show. The differential pressure measuring tube in the above device can be a backrest dynamic pressure tube or a flute tube. The structure of the overall device is complex. Poor sealing or leakage at the weld of the pressure transmission pipe, and problems such as blockage in the pressure transmission pipe lead to inaccurate measurement results. When there are many measuring devices, the number of pressure transmission pipes will also increase, which will inevitably increase the difficulty of on-site construction. It affects the appearance and also increases the risk of leakage. At the same time, it increases the difficulty of debugging the measurement system and increases the construction cost.

Contents of the invention

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a boiler primary wind speed differential pressure measuring device with simple structure, convenient installation and use, and accurate measurement results.

The technical scheme that the utility model takes is:

A boiler primary wind speed differential pressure measurement device, including a differential pressure measurement tube and a signal processing unit. Two air outlet pipes parallel to each other are made on the outer wall of the same side of the body, and the feature is that: the outer ends of the two air outlet pipes installed on the differential pressure measuring pipe are directly connected to the two air outlet pipes of the signal processing unit Port fixed connection.

Moreover, the outer ends of the two air outlet pipes installed on the differential pressure measuring pipe are fixedly connected to the two wind measuring ports of the signal processing unit through ferrule-type pressure connection joints.

Moreover, the included angle between the axis of the outlet pipe and the axis of the differential pressure measuring pipe connected thereto is 20-40°.

Moreover, the differential pressure measuring tube is a backrest dynamic pressure tube or a piccolo tube.

Moreover, a flexible cleaning rod coaxial with the pipe body is suspended and installed in each pipe body of the backrest type dynamic pressure pipe.

Moreover, wear-resistant layers are covered and installed on the outer walls of the two pipe bodies located below the lower end surface of the flange of the backrest dynamic pressure pipe.

Advantage and positive effect of the present utility model are:

1. The two wind measuring ports of the signal processing unit in this device are directly fixedly connected with the outer end of the air duct made on the differential pressure measuring tube, instead of using the traditional pressure transmission tube made of carbon steel, which not only reduces the It reduces the cost of materials, solves the problem of complicated construction caused by too many pipelines, reduces the risk of leakage and construction costs, and improves the accuracy of measurement.

2. The signal processing unit and the air outlet pipe in this device are fixedly connected by a joint, which is a ferrule-type pressure connection joint of LF-LOK. After using this joint, the air between the signal processing unit and the air outlet pipe The tightness is good, and the joint is easy to disassemble and will not be distorted due to thermal stress due to high working temperature.

3. Each tube body of the back-type dynamic pressure tube in this device is hung with a flexible dust removal rod, which can swing randomly under the impact of the air flow to play the role of automatic dust removal, and at the same time The air outlet pipe made on the backrest dynamic pressure pipe plays the role of secondary dust removal. The two cleaning processes can prevent the measuring device from being blocked by the pulverized coal transported by the primary wind, and ensure the accuracy of the measurement.

4. The backrest type dynamic pressure tube in this device is located on the outer wall of the two tubes on the lower end of the flange, and is covered with a wear-resistant layer by viscose. The material of the wear-resistant layer is corundum ceramics, which has high hardness, Wear resistance, high temperature resistance, corrosion resistance and other advantages.

5. The utility model integrates the functions of each single device such as a measuring probe and a signal processing unit. The differential pressure measuring tube can use a backrest dynamic pressure tube or a flute tube. The overall device has the advantages of lightness, compactness, and simple structure. Advantages: It has a high protection level, is more convenient to install and use, greatly reduces construction costs, improves the reliability of the measuring device, and ensures the accuracy of the measurement.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the left view of Fig. 1;

Fig. 3 is a sectional view of A-A in Fig. 2 (the fixing bolt of the cleaning rod, the ferrule-type pressure connection joint and the signal processing unit are not sectioned);

Fig. 4 is the use state figure of the utility model;

Fig. 5 is the use state figure of embodiment 2;

Fig. 6 is a diagram of the state of use in the prior art.

Detailed ways

Below in conjunction with embodiment, the utility model is further described, and following embodiment is illustrative, not limiting, can not limit protection scope of the present utility model with following embodiment.

The differential pressure measuring tube in the utility model can use a backrest type dynamic pressure tube, or a flute tube, and the two structures are described through Embodiment 1 and Embodiment 2 respectively. Wherein, the differential pressure measuring tube in embodiment 1 is a backrest dynamic pressure tube, and the differential pressure measuring tube in embodiment 2 is a flute tube.

A boiler primary wind speed differential pressure measurement device, as shown in Figures 1 to 3, includes a differential pressure measurement tube 5 and a signal processing unit 2 mainly composed of a differential pressure transmitter. The differential pressure measurement tube is mounted on the In the flange 6, two air outlet pipes 3 parallel to each other are made on the outer walls of the two pipe bodies of the differential pressure measuring tube above the upper end surface of the flange. The differential pressure measuring tube in this embodiment is Backrest type dynamic pressure tube, the innovation of the utility model is that: the outer ends of the two air outlet tubes are directly fixedly connected with the two wind measuring ports of the signal processing unit.

The signal processing unit and the air outlet pipe can be fixed directly, or a ferrule-type pressure connection joint 8 can be installed between the outer ends of the two air outlet pipes and the two wind measuring ports of the signal processing unit. The joint is LF -LOK compression fittings for compression fittings. After using the joint, the airtightness between the signal processing unit and the air outlet pipe is good, and the joint is easy to disassemble and will not be distorted due to thermal stress due to high working temperature.

Since the primary air transports powdery materials, in order to avoid blockage of the back-type dynamic pressure tube, a secondary dust-cleaning structure is installed in the back-type dynamic pressure tube. A flexible cleaning rod 9 coaxial with the pipe body is arranged in the pipe body, and the upper end of the flexible cleaning rod is suspended and installed on the lower surface of the cleaning rod fixing bolt 1 installed on the upper end of each pipe body of the backrest type dynamic pressure tube. . The flexible dust cleaning rod swings randomly under the impact of the airflow in the pipe, which plays the role of cleaning dust for the first time. The second dust cleaning structure is the air outlet pipe (H in Figure 2) made of each pipe body of the back-type dynamic pressure pipe at the height of 1/3 above the upper end of the flange. The axis of the air outlet pipe and its connection The included angle α between the axes of the backrest dynamic pressure pipe body is 20-40°, preferably 30°. After the airflow enters the air outlet pipe, the powdery material in it is buffered and decelerated, and settles down, which plays a role in secondary sedimentation. The effect of gray.

The differential pressure transmitter in the aforementioned signal processing unit adopts the special differential pressure transmitter of the model168 series of Alpha Company, which adopts a variable capacitor composed of a stainless steel diaphragm and a fixed electrode, and is equipped with high-precision electronic components. Small size, light weight, high stability and anti-interference ability. The input end of the transmitter is customized to match the size and spacing of the outer ends of the two outlet pipes of the backrest dynamic pressure tube, and a Hirschmann electrical output connection assembly 4 can also be installed at the output end of the transmitter to improve Transmission reliability and anti-interference ability of current signal, and has good water resistance. The flow rate differential pressure signal of the backrest dynamic pressure tube is transmitted to the signal processing unit through the air outlet tube, and the differential pressure signal is converted into a standard DC current signal of 4-20mA (or 0-10mA), which is received by the computer and processed. Computing and displaying.

The signal processing unit is an integrated design, and its protection level is IP65. It runs stably during the field test. Under the working temperature of 60°C, the temperature drift is less than ±0.06% FS/°C, and the measurement error is ±0.25% FS. It can be seen that its anti-interference ability is good, and it is not affected by the heat dissipation temperature and vibration of the pipeline.

The use status diagram of the utility model is shown in Figure 4, the backrest type dynamic pressure tube is made of stainless steel material, the flange is made of iron material, and its vertical height is slightly greater than the thickness of the surface insulation layer of the primary air duct 10, so as to After the measuring probe is installed, its flange connection will not be covered by the insulation layer. A wear-resistant layer 7 is installed on the outer walls of the two pipe bodies below the lower end surface of the flange of the backrest dynamic pressure pipe to protect the stainless steel pipe body. The wear-resistant layer is corundum ceramics, which is a kind of Al ₂ O ₃ is the main raw material, supplemented by solvents such as rare metal oxides, and is a special ceramic made by sintering at a high temperature of 1700 ° C. It has the advantages of high hardness, wear resistance, high temperature resistance, and corrosion resistance. Its Rockwell hardness (HRA) ≥80, bulk density (g/cm ³ )≥3.5, water absorption (%)≤0.03.

Example 2

The difference between this embodiment and Embodiment 1 is shown in Figure 5. The differential pressure measuring pipe is a flute-shaped pipe, and there is no flexible cleaning rod installed in the flute-shaped pipe. The outer wall of the pipe body is not covered with a wear-resistant layer, and other structures and usage methods are the same as in Embodiment 1. The flute pipe in this embodiment is not in the prior art, and the change lies in the connection between the air outlet pipe and the signal processing unit, so a structural schematic diagram of a sectioned flute pipe is not provided.

Claims (6)

1. boiler primary air velocity differential pressure type measurement mechanism, comprise differential pressure type measuring tube and signal processing unit, the differential pressure type measuring tube is installed in the flange, be positioned on the homonymy outer wall of two bodys of the above differential pressure type measuring tube in flange upper surface and make two discharge pipes that are parallel to each other, it is characterized in that: the outboard end of two discharge pipes installing on the described differential pressure type measuring tube is directly fixedlyed connected with two survey wind ports of signal processing unit.

2. boiler primary air velocity differential pressure type measurement mechanism according to claim 1 is characterized in that: two discharge pipe outboard end of installing on the described differential pressure type measuring tube are surveyed between the wind port with two of signal processing units and are fixedlyed connected by bite type pressure jointing.

3. boiler primary air velocity differential pressure type measurement mechanism according to claim 1 is characterized in that: the angle between described discharge pipe axis and the connected differential pressure type measuring tube axis is 20～40 °.

4. according to claim 1 or 2 or 3 described boiler primary air velocity differential pressure type measurement mechanisms, it is characterized in that: described differential pressure type measuring tube is backrest type dynamic pressure tube or bourdon's tube.

5. boiler primary air velocity differential pressure type measurement mechanism according to claim 4 is characterized in that: all hang in the every body of described backrest type dynamic pressure tube a flexible deashing rod coaxial with body is installed.

6. boiler primary air velocity differential pressure type measurement mechanism according to claim 4 is characterized in that: be positioned at the backrest type dynamic pressure tube all to coat on the outer wall of two bodys below the flange lower surface wearing layer is installed.

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