Differential pressure flowmeter for measuring high-pressure steam

Abstract

The utility model relates to a differential pressure flowmeter for measuring high-pressure steam, which comprises a venturi tube, the venturi tube comprises a first delivery pipe, a first reducer pipe, a second delivery pipe, a second reducer pipe and a third delivery pipe, the first delivery pipe is provided with a plurality of inlet ends of first pressure tapping pipes, and the second delivery pipe is provided with a plurality of outlet ends of second pressure tapping pipes. The first conveying pipe is provided with inlet ends of a plurality of first pressure tapping pipes, the second conveying pipe is provided with inlet ends of a plurality of second pressure tapping pipes, outlet ends of the plurality of first pressure tapping pipes are communicated with an inlet end of a third pressure tapping pipe, an outlet end of the third pressure tapping pipe is provided with a first buffer tank, and outlet ends of the plurality of second pressure tapping pipes are communicated with an inlet end of a fourth pressure tapping pipe; a second buffer tank is arranged at the outlet end of the fourth pressure tapping pipe, a pressure difference measuring pipe is arranged between the second buffer tank and the first buffer tank, and a pressure difference transmitter is arranged on the pressure difference measuring pipe. And accumulated water easily caused in a pipeline in front of the throttling device is reduced. The utility model has the advantages of convenient use and wide market prospect.

Description

Technical Field

[0001] The utility model relates to the field of differential pressure flow devices, and particularly to a differential pressure flowmeter for measuring high-pressure steam. Background Art

[0002] The differential pressure flowmeter is based on the throttling principle of fluid flow and realizes flow measurement by using the pressure difference generated when the fluid flows through the throttling device. It is one of the most mature and commonly used methods for measuring flow in production at present. It usually consists of a throttling device that can convert the measured flow into a differential pressure signal, a differential pressure gauge that can convert this differential pressure into a corresponding flow value for display, and a display instrument. In the unit combination instrument, the differential pressure signal generated by the throttling device is often converted into a corresponding standard signal through a differential pressure transmitter for display, recording, or control.

[0003] Our company applied on September 18, 2023, with the publication number CN202322524831.6 and the name of a differential pressure flowmeter. This patent application mainly solves the technical problem that the differential pressure transmitter is prone to damage due to poor high-temperature tolerance under the working condition of measuring high-pressure steam by using a throttling nozzle as the throttling device. After this product was launched on the market, according to customer feedback, due to the technical problem of water accumulation easily occurring in front of the throttling nozzle, it is necessary for the staff to regularly open the drain valve in front of the throttling nozzle to drain the accumulated water in the pipeline in front of the throttling nozzle. After actual investigation and analysis, it is because while the pressure tapping pipe in front of the throttling nozzle continuously transmits the pressure of high-pressure steam to the corresponding buffer tank, part of the high-pressure steam is liquefied and generates a backflow, which continuously flows back into the pipeline in front of the throttling nozzle. Furthermore, since the liquefied water generated by the liquefaction of high-pressure steam during the transportation process through the pipeline is also transported along with the high-pressure steam and is centrally discharged by the pipeline drainer installed on this pipeline. However, the feed water that flows back to the front of the throttling nozzle after the high-pressure steam cools is blocked by the throttling nozzle and cannot all be transported to the drainer in the downstream pipeline along with the airflow passing through the throttling nozzle, resulting in easy water accumulation in the pipeline in front of the throttling nozzle. Therefore, there is room for improvement in the prior art to reduce the technical problem of easy water accumulation before the throttling device, thereby reducing the operational convenience. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the utility model provides a differential pressure flowmeter for measuring high-pressure steam that can reduce the water accumulation in the pipeline before the throttling device, so as to overcome the defects in the prior art.

[0005] The technical solution adopted by the present utility model is as follows: A differential pressure flowmeter for measuring high-pressure steam includes a Venturi tube. The Venturi tube sequentially includes a first delivery pipe, a first reducing pipe, a second delivery pipe, a second reducing pipe, and a third delivery pipe along the direction from the inlet end to the outlet end of the Venturi tube. The inlet ends of a number of first pressure-taking pipes are arranged on the first delivery pipe. The inlet ends of a number of second pressure-taking pipes are arranged on the second delivery pipe. The outlet ends of the number of first pressure-taking pipes are communicated with the inlet end of a third pressure-taking pipe. The outlet end of the third pressure-taking pipe is provided with a first buffer tank. The outlet ends of the number of second pressure-taking pipes are communicated with the inlet end of a fourth pressure-taking pipe. The outlet end of the fourth pressure-taking pipe is provided with a second buffer tank. A differential pressure measuring pipe is arranged between the second buffer tank and the first buffer tank. A differential pressure transmitter is arranged on the differential pressure measuring pipe.

[0006] Preferably, the inner cavity cross-section of the Venturi tube is circular. The inscribed circle diameters of the first reducing pipe and the second reducing pipe both gradually decrease along the direction from away from the second delivery pipe to close to the second delivery pipe. The inner wall junctions between the first delivery pipe and the first reducing pipe, between the first reducing pipe and the second delivery pipe, between the second delivery pipe and the second reducing pipe, and between the second reducing pipe and the third delivery pipe all adopt arc transitions.

[0007] Preferably, the inlet ends of the number of first pressure-taking pipes are all located above the central axis of the first delivery pipe. The inlet ends of the number of second pressure-taking pipes are all located above the central axis of the second delivery pipe. The number of first pressure-taking pipes and the third pressure-taking pipe are connected and communicated through a first pressure equalizing pipe. The number of second pressure-taking pipes and the fourth pressure-taking pipe are connected and communicated through a second pressure equalizing pipe.

[0008] Preferably, both the first pressure equalizing pipe and the second pressure equalizing pipe adopt an arc-shaped tubular structure with both ends sealed. The top end of the first pressure equalizing pipe is communicated with the bottom end of the third pressure-taking pipe. The third pressure-taking pipe is vertically installed on the first pressure equalizing pipe. The number of first pressure-taking pipes are evenly distributed between the first pressure equalizing pipe and the third pressure-taking pipe. The top end of the second pressure equalizing pipe is communicated with the bottom end of the fourth pressure-taking pipe. The fourth pressure-taking pipe is vertically installed on the second pressure equalizing pipe. The number of second pressure-taking pipes are evenly distributed between the second pressure equalizing pipe and the fourth pressure-taking pipe.

[0009] Preferably, ball valves are respectively arranged on the differential pressure measuring pipe between the second buffer tank and the differential pressure measuring pipe, on the differential pressure measuring pipe between the differential pressure measuring pipe and the first buffer tank, and on the third pressure-taking pipe and the fourth pressure-taking pipe.

[0010] Preferably, a number of heat dissipation discs are respectively arranged at intervals on the third pressure-taking pipe and the fourth pressure-taking pipe.

[0011] Preferably, both the second buffer tank and the first buffer tank adopt a hollow spherical structure. Liquid level sensors are respectively arranged on the second buffer tank and the first buffer tank. Pressure relief pipes are respectively arranged at the tops of the second buffer tank and the first buffer tank, and drain pipes are respectively arranged at the bottoms of the second buffer tank and the first buffer tank. Sealing heads are respectively arranged on each pressure relief pipe and each drain pipe.

[0012] The beneficial effects of the present utility model are as follows: First, the venturi tube is adopted as the measuring tube in the present utility model, thus reducing the technical problem that water is likely to accumulate in the pipeline before the throttling device for high-pressure steam; and furthermore, several first pressure tapping pipes are installed on the first conveying pipe and several second pressure tapping pipes are installed on the second conveying pipe, thereby increasing the pressure acquisition positions. The pressures collected at multiple points are equalized by the first pressure equalizing pipe and then conveyed to the third pressure tapping pipe or equalized by the second pressure equalizing pipe and then conveyed to the fourth pressure tapping pipe, so that the pressure value received by the third pressure tapping pipe is closer to the pressure value in the first conveying pipe and the pressure value received by the fourth pressure tapping pipe is closer to the pressure value in the second conveying pipe.

[0013] Second, pressure relief pipes are respectively arranged at the tops of the second buffer tank and the first buffer tank of the present utility model, and drain pipes are respectively arranged at the bottoms of the second buffer tank and the first buffer tank. Sealing heads are respectively arranged on each pressure relief pipe and each drain pipe; the installation of the pressure relief pipes and the drain pipes facilitates opening the corresponding sealing heads during the maintenance process to discharge the liquid stored in the second buffer tank or the first buffer tank.

[0014] Third, liquid level sensors are respectively arranged on the second buffer tank and the first buffer tank of the present utility model. The installation of the liquid level sensors facilitates the feedback of liquid level parameters.

[0015] The present utility model has the advantages of simple structure, convenient operation, ingenious design, greatly improving the work efficiency, having good social and economic benefits, and being a product easy to promote and use. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the present utility model.

[0017] Figure 2 It is a schematic structural diagram of the present utility model.

[0018] Figure 3 It is a schematic structural diagram of the components of the present utility model. Detailed Embodiments

[0019] Such as Figures 1 to 3As shown in the figure, a differential pressure flowmeter for measuring high-pressure steam includes a Venturi tube. The Venturi tube sequentially includes a first conveying pipe 1, a first reducing pipe 2, a second conveying pipe 3, a second reducing pipe 4, and a third conveying pipe 5 along the direction from the inlet end to the outlet end of the Venturi tube. The inlet ends of a plurality of first pressure-taking pipes 6 are arranged on the first conveying pipe 1, and the inlet ends of a plurality of second pressure-taking pipes 7 are arranged on the second conveying pipe 3. The outlet ends of the plurality of first pressure-taking pipes 6 are connected to the inlet end of a third pressure-taking pipe 8, and a first buffer tank 9 is arranged at the outlet end of the third pressure-taking pipe 8. The outlet ends of the plurality of second pressure-taking pipes 7 are connected to the inlet end of a fourth pressure-taking pipe 10, and a second buffer tank 11 is arranged at the outlet end of the fourth pressure-taking pipe 10. A differential pressure measuring pipe 12 is arranged between the second buffer tank 11 and the first buffer tank 9, and a differential pressure transmitter 13 is arranged on the differential pressure measuring pipe 12. The inner cavity cross-section of the Venturi tube is circular. The inscribed circle diameters of the first reducing pipe 2 and the second reducing pipe 4 gradually decrease along the direction away from the second conveying pipe 3 to approaching the second conveying pipe 3. The inner wall junctions between the first conveying pipe 1 and the first reducing pipe 2, between the first reducing pipe 2 and the second conveying pipe 3, between the second conveying pipe 3 and the second reducing pipe 4, and between the second reducing pipe 4 and the third conveying pipe 5 all adopt arc transitions. Thus, when the high-pressure steam passes through the inner wall junctions between the first conveying pipe 1 and the first reducing pipe 2, between the first reducing pipe 2 and the second conveying pipe 3, between the second conveying pipe 3 and the second reducing pipe 4, and between the second reducing pipe 4 and the third conveying pipe 5, the pressure of the high-pressure steam changes smoothly, thereby reducing the pressure fluctuation amplitude. The inlet ends of the plurality of first pressure-taking pipes 6 are all located above the central axis of the first conveying pipe 1, and the inlet ends of the plurality of second pressure-taking pipes 7 are all located above the central axis of the second conveying pipe 3. The plurality of first pressure-taking pipes 6 and the third pressure-taking pipe 8 are connected by a first pressure equalizing pipe 14, and the plurality of second pressure-taking pipes 7 and the fourth pressure-taking pipe 10 are connected by a second pressure equalizing pipe 15. Installing the first pressure equalizing pipe 14 facilitates equalizing the pressures conveyed by the plurality of first pressure-taking pipes 6 and then conveying them to the third pressure-taking pipe 8, and installing the second pressure equalizing pipe 15 facilitates equalizing the pressures conveyed by the plurality of first pressure-taking pipes 6 and then conveying them to the fourth pressure-taking pipe 10.The described first pressure equalizing pipe 14 and second pressure equalizing pipe 15 both adopt an arc-shaped tubular structure with sealed ends. The top end of the first pressure equalizing pipe 14 is communicated with the bottom end of the third pressure tapping pipe 8. The third pressure tapping pipe 8 is vertically installed on the first pressure equalizing pipe 14. A plurality of first pressure tapping pipes 6 are evenly distributed between the first pressure equalizing pipe 14 and the third pressure tapping pipe 8. The top end of the second pressure equalizing pipe 15 is communicated with the bottom end of the fourth pressure tapping pipe 10. The fourth pressure tapping pipe 10 is vertically installed on the second pressure equalizing pipe 15. A plurality of second pressure tapping pipes 7 are evenly distributed between the second pressure equalizing pipe 15 and the fourth pressure tapping pipe 10.

[0020] Ball valves 16 are respectively arranged on the pressure difference measuring pipe 12 between the described second buffer tank 11 and the pressure difference measuring pipe 12, the pressure difference measuring pipe 12 between the pressure difference measuring pipe 12 and the first buffer tank 9, and the third pressure tapping pipe 8 and the fourth pressure tapping pipe 10. A plurality of heat dissipation discs 17 are respectively arranged at intervals on the third pressure tapping pipe 8 and the fourth pressure tapping pipe 10. Since the measured medium is high-pressure steam, the heat dissipation discs 17 are installed in this product to facilitate reducing the temperature of the passing medium. Further, the thickness of the outer part of each heat dissipation disc 17 gradually decreases as the diameter of the heat dissipation disc 17 gradually increases; thus increasing the heat exchange area of the heat dissipation disc 17.

[0021] The described second buffer tank 11 and the first buffer tank 9 both adopt a hollow spherical structure, which is more convenient for stabilizing pressure and reducing excessive local pressure. Liquid level sensors 18 are respectively arranged on the second buffer tank 11 and the first buffer tank 9. Relief pipes 19 are respectively arranged at the top ends of the second buffer tank 11 and the first buffer tank 9. Drain pipes 20 are respectively arranged at the bottoms of the second buffer tank 11 and the first buffer tank 9. Sealing heads 21 are respectively arranged on each relief pipe 19 and each drain pipe 20. Connecting flanges 22 are respectively arranged at one end of the first conveying pipe 1 away from the first reducer 2 and one end of the third conveying pipe 5 away from the second reducer 4.

[0022] The usage method of this product is as follows: As Figures 1 to 3 shown, after installing this product at the preset installation position on the high-pressure steam conveying pipeline, purified water is added through the relief pipe 19 on the first buffer tank 9. When the liquid level sensor 18 on the first buffer tank 9 reaches the preset liquid level height, the corresponding sealing head 21 is covered; similarly, purified water is added through the relief pipe 19 on the second buffer tank 11. When the liquid level sensor 18 on the second buffer tank 11 reaches the preset liquid level height, the corresponding sealing head 21 is covered. At this time, the ball valves 16 on the third pressure tapping pipe 8 and the fourth pressure tapping pipe 10 are both in the closed state. After completing the above operations, the preparation work before the measurement of this product is completed.

[0023] In the initial startup state of the high-pressure steam transmission system, keep the ball valves 16 on the third pressure-taking pipe 8 and the ball valves 16 on the fourth pressure-taking pipe 10 in the closed state. After the high-pressure steam is transmitted for a preset time and the high-pressure steam flow rate and high-pressure steam pressure in the corresponding pipelines tend to be stable, the ball valves 16 on the third pressure-taking pipe 8 and the ball valves 16 on the fourth pressure-taking pipe 10 can be opened. At this time, part of the high-pressure steam passing through the first transmission pipe 1 enters into a plurality of first pressure-taking pipes 6. The high-pressure steam conveyed by the plurality of first pressure-taking pipes 6 is equalized by the first pressure equalizing pipe 14 and then conveyed to the third pressure-taking pipe 8. The third pressure-taking pipe 8 compresses the air in the upper layer of the liquid surface in the first buffer tank 9 and forms a positive pressure on the liquid in the first buffer tank 9. The liquid in the first buffer tank 9 conveys the pressure to the first end of the differential pressure transmitter 13 to form a first pressure signal.

[0024] The described high-pressure steam continues to move forward along the first transmission pipe 1 and is conveyed to the first reducing pipe 2. During the conveying process of the high-pressure steam in the first reducing pipe 2, as the high-pressure steam gradually approaches the second transmission pipe 3, the high-pressure steam is gradually throttled as the inner cavity diameter of the first reducing pipe 2 decreases. When the high-pressure steam is conveyed to the second transmission pipe 3, the flow rate of the described high-pressure steam reaches the maximum value. The second transmission pipe 3 conveys high-pressure steam to a plurality of second pressure-taking pipes 7. The high-pressure steam conveyed by the plurality of second pressure-taking pipes 7 is equalized by the second pressure equalizing pipe 15 and then conveyed to the fourth pressure-taking pipe 10. The fourth pressure-taking pipe 10 compresses the air in the upper layer of the liquid surface in the second buffer tank 11 and forms a positive pressure on the liquid in the second buffer tank 11. The liquid in the second buffer tank 11 conveys the pressure to the second end of the differential pressure transmitter 13 to form a second pressure signal. The differential pressure transmitter 13 converts the obtained first pressure signal and the second pressure signal into flow parameters.

[0025] After the steam enters the third pressure-taking pipe 8 or the fourth pressure-taking pipe 10, the heat dissipation disc 17 of the third pressure-taking pipe 8 exchanges heat with the outside atmosphere or the heat dissipation disc 17 of the fourth pressure-taking pipe 10 exchanges heat with the outside atmosphere, thereby reducing the temperature of the third pressure-taking pipe 8 above the heat dissipation disc 17 or the temperature of the fourth pressure-taking pipe 10 above the heat dissipation disc 17, thereby reducing the working temperature when the first buffer tank 9 measures high-pressure steam or reducing the working temperature when the second buffer tank 11 measures high-pressure steam. After the steam entering the first buffer tank 9 or the steam entering the second buffer tank 11 is liquefied, it causes the liquid level of the first buffer tank 9 to rise or causes the liquid level of the second buffer tank 11 to rise until the liquid in the first buffer tank 9 is sent back to the first delivery pipe 1 through the third pressure-taking pipe 8 or until the liquid of the second buffer tank 11 is sent back to the second delivery pipe 3 through the fourth pressure-taking pipe 10, and the high-pressure steam continuously passing through the first delivery pipe 1, the first reducing pipe 2, the second delivery pipe 3, the second reducing pipe 4 and the third delivery pipe 5 carries the liquid sent back to the first delivery pipe 1 and the liquid sent back to the second delivery pipe 3 and transports them downstream, and is centrally discharged through the drain installed on the high-pressure steam delivery pipeline.

[0026] Through this embodiment, since the venturi tube is used as the measuring tube in this product, the technical problem that water is likely to accumulate in the pipeline before the throttling device for high-pressure steam is reduced; and furthermore, a number of first pressure-taking pipes 6 are installed on the first delivery pipe 1 and a number of second pressure-taking pipes 7 are installed on the second delivery pipe 3, thereby increasing the pressure acquisition positions, and the pressures collected at multiple points are equalized by the first equalizing pipe 14 and then transported to the third pressure-taking pipe 8 or equalized by the second equalizing pipe 15 and then transported to the fourth pressure-taking pipe 10. The third pressure-taking pipe 8 causes the pressure of the upper layer of the liquid in the first buffer tank 9 to rise as the first pressure signal source, and the fourth pressure-taking pipe 10 causes the pressure of the upper layer of the liquid in the second buffer tank 11 to rise as the second pressure signal source, which also reduces the working temperature of the differential pressure transmitter 13 and improves the durability of the differential pressure transmitter 13.

[0027] The above-mentioned embodiments are only the preferred embodiments of the present invention, and do not limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the present invention patent shall be included in the scope of the patent application of the present invention.

Claims

1. A differential pressure flow meter for measuring high-pressure steam, characterized in that: The invention comprises a venturi tube, wherein the venturi tube comprises a first delivery tube (1), a first reducer (2), a second delivery tube (3), a second reducer (4) and a third delivery tube (5) in sequence from the inlet end of the venturi tube to the outlet end of the venturi tube, the first delivery tube (1) is provided with the inlet ends of a plurality of first pressure-taking tubes (6), the second delivery tube (3) is provided with the inlet ends of a plurality of second pressure-taking tubes (7), the outlet ends of the plurality of first pressure-taking tubes (6) are connected to the inlet ends of the third pressure-taking tube (8), the outlet end of the third pressure-taking tube (8) is provided with a first buffer tank (9), the outlet ends of the plurality of second pressure-taking tubes (7) are connected to the inlet end of the fourth pressure-taking tube (10), A second buffer tank (11) is provided at the outlet end of the fourth pressure taking pipe (10), a differential pressure measuring pipe (12) is provided between the second buffer tank (11) and the first buffer tank (9), and a differential pressure transmitter (13) is provided on the differential pressure measuring pipe (12).

2. The differential pressure flow meter for measuring high-pressure steam according to claim 1, characterized in that: The inner cavity cross-section of the Venturi tube is circular, the inscribed circle diameter of the first reducer (2) and the inscribed circle diameter of the second reducer (4) both gradually decrease in a direction away from the second delivery tube (3) and closer to the second delivery tube (3), and the intersection of the inner walls between the first delivery tube (1) and the first reducer (2), the intersection of the inner walls between the first reducer (2) and the second delivery tube (3), the intersection of the inner walls between the second delivery tube (3) and the second reducer (4), and the intersection of the inner walls between the second reducer (4) and the third delivery tube (5) all adopt circular arc transitions.

3. The differential pressure flow meter for measuring high-pressure steam according to claim 1, characterized in that: The inlet ends of the plurality of first pressure-taking tubes (6) are all located above the central axis of the first delivery tube (1), the inlet ends of the plurality of second pressure-taking tubes (7) are all located above the central axis of the second delivery tube (3), the plurality of first pressure-taking tubes (6) and the third pressure-taking tube (8) are connected via a first pressure-equalizing tube (14), and the plurality of second pressure-taking tubes (7) and the fourth pressure-taking tube (10) are connected via a second pressure-equalizing tube (15).

4. The differential pressure flow meter for measuring high-pressure steam according to claim 3, characterized in that: The first pressure-equalizing tube (14) and the second pressure-equalizing tube (15) both adopt an arc-shaped tubular structure with sealed ends; the top end of the first pressure-equalizing tube (14) is connected to the bottom end of the third pressure-taking tube (8); the third pressure-taking tube (8) is vertically mounted on the first pressure-equalizing tube (14); a plurality of first pressure-taking tubes (6) are evenly distributed between the first pressure-equalizing tube (14) and the third pressure-taking tube (8); the top end of the second pressure-equalizing tube (15) is connected to the bottom end of the fourth pressure-taking tube (10); the fourth pressure-taking tube (10) is vertically mounted on the second pressure-equalizing tube (15); and a plurality of second pressure-taking tubes (7) are evenly distributed between the second pressure-equalizing tube (15) and the fourth pressure-taking tube (10).

5. The differential pressure flow meter for measuring high-pressure steam according to claim 1, characterized in that: Ball valves (16) are respectively provided on the pressure differential measuring tube (12) between the second buffer tank (11) and the pressure differential measuring tube (12), the pressure differential measuring tube (12) between the pressure differential measuring tube (12) and the first buffer tank (9), the third pressure taking tube (8) and the fourth pressure taking tube (10).

6. The differential pressure flow meter for measuring high-pressure steam according to claim 1, characterized in that: A plurality of heat dissipation plates (17) are respectively arranged at intervals on the third pressure-taking tube (8) and the fourth pressure-taking tube (10).

7. The differential pressure flow meter for measuring high-pressure steam according to claim 1, characterized in that: The second buffer tank (11) and the first buffer tank (9) both adopt a hollow spherical structure, and the second buffer tank (11) and the first buffer tank (9) are respectively provided with a liquid level sensor (18), the top of the second buffer tank (11) and the top of the first buffer tank (9) are respectively provided with a pressure relief pipe (19), the bottom of the second buffer tank (11) and the bottom of the first buffer tank (9) are respectively provided with a drainage pipe (20), and each pressure relief pipe (19) and each drainage pipe (20) are respectively provided with a head (21).

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