Device for detecting backpressure ratio of critical flow venturi nozzle

Abstract

The utility model relates to the field of natural gas stations, in particular to a device for detecting the back pressure ratio of a critical flow venturi nozzle. The device for detecting the backpressure ratio of the critical flow venturi nozzle comprises the critical flow venturi nozzle, a detection pipeline and a backpressure ratio detection control system, the critical flow venturi nozzle is arranged on the detection pipeline in a communicated mode, detection points are arranged on the detection pipeline corresponding to the two ends of the critical flow venturi nozzle respectively, and the backpressure ratio detection control system is connected with the detection pipeline. And the backpressure ratio detection control system is used for collecting a pressure difference value of the two detection points. The gas flow standard device has the advantages of being simple and reasonable in structural design, capable of effectively monitoring the pressure difference between the front portion and the rear portion of the critical flow venturi nozzle and judging whether the throat of the nozzle reaches the critical flow state or not, and capable of effectively improving the reliability of the gas flow standard device adopting the critical flow venturi nozzle method.

Description

TECHNICAL FIELD

[0001] The utility model relates to natural gas station field field, especially a critical flow venturi nozzle back pressure ratio detection's device. BACKGROUND

[0002] Critical flow venturi nozzle method gas flow standard device is the most widely used, the most stable performance of a transfer standard device of measurement technology institutions at home and abroad, is composed of parallel critical flow venturi nozzle, supporting process pipeline, rectifier and temperature, pressure transmitter, plays a key role in the upper and lower in our country medium and high pressure natural gas value transmission system. It is mainly used for calibrating working level standard turbine flowmeter and customer's high-precision flowmeter.

[0003] At present, in the field of natural gas station, generally uses two pressure measuring devices to monitor whether the nozzle throat reaches the critical flow state, a set of standard device is composed of multiple parallel critical flow venturi nozzles, therefore, a set of secondary standard device contains too many detection instruments, which leads to problems such as reduced equipment reliability, increased data acquisition points and communication cables.

[0004] Therefore, it is necessary to develop a critical flow venturi nozzle back pressure ratio detection device to overcome the above technical problems. UTILITY MODEL CONTENT

[0005] The utility model solves the technical problem that a critical flow venturi nozzle back pressure ratio detection device is provided to effectively overcome the defects of the prior art.

[0006] The technical solution of the utility model to solve the above technical problems is as follows:

[0007] A critical flow venturi nozzle back pressure ratio detection device, comprising a critical flow venturi nozzle, a detection pipeline and a back pressure ratio detection control system, the critical flow venturi nozzle is connected to the detection pipeline, the detection pipeline has detection points at both ends corresponding to the critical flow venturi nozzle, and the back pressure ratio detection control system is used to collect the pressure difference of the two detection points.

[0008] Based on the above technical solution, the utility model can also be improved as follows.

[0009] Further, the back pressure ratio detection control system comprises a differential pressure transmitter, and the two detection points are connected with pipelines, and the pipelines are connected to the inlet of the differential pressure transmitter.

[0010] Further, the differential pressure transmitter is connected to the background intelligent terminal network through a first communication device.

[0011] Further, the first communication device is a 4G / 5G communication device.

[0012] Further, the back pressure ratio detection control system comprises a processor and two pressure detectors, the two pressure detectors are respectively arranged at the two detection points, and are respectively used for detecting pressure values upstream and downstream of the critical flow Venturi nozzle.

[0013] Further, the pressure detector is an electronic pressure gauge.

[0014] Further, the processor is connected with a background intelligent terminal network through a second communication device.

[0015] Further, the second communication device is a 4G / 5G communication device.

[0016] Further, a switch valve is arranged downstream of the detection pipeline.

[0017] Further, a pipe bundle rectifier is connected in series upstream of the detection pipeline.

[0018] The utility model discloses a critical flow Venturi nozzle back pressure ratio detection device, which comprises a critical flow Venturi nozzle, a detection pipeline, a differential pressure transmitter and a pressure detector. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is the schematic diagram of the critical flow Venturi nozzle back pressure ratio detection device of the utility model. Figure 1

[0020] Figure 2 It is the schematic diagram of the critical flow Venturi nozzle back pressure ratio detection device of the utility model. Figure 2

[0021] Figure 3 It is the schematic diagram of the critical flow Venturi nozzle back pressure ratio detection device of the utility model. Figure 3 In the drawings, the components represented by each reference numeral are listed as follows:

[0022] 1, critical flow Venturi nozzle; 2, detection pipeline; 3, differential pressure transmitter; 4, pressure detector; 5, pipe bundle rectifier. DETAILED DESCRIPTION

[0023] The principles and characteristics of the utility model are described below in combination with the drawings, and the examples are only used for explaining the utility model and are not used for limiting the range of the utility model.

[0024] Embodiment: as Figure 1 and 2 ​​As shown, the critical flow venturi nozzle back pressure ratio detection device of this embodiment includes a critical flow venturi nozzle 1, a detection line 2, and a back pressure ratio detection control system. The critical flow venturi nozzle 1 is connected to the detection line 2. The detection line 2 is provided with detection points at both ends of the critical flow venturi nozzle 1. The back pressure ratio detection control system is used to collect the pressure difference between the two detection points.

[0025] The critical flow Venturi nozzle back pressure ratio detection device in this embodiment utilizes an existing critical flow Venturi nozzle method gas flow standard device. Natural gas enters the critical flow Venturi nozzle 1 after passing through the detection pipeline 2, and then flows out of the standard device. When natural gas flows through the critical flow Venturi nozzle 1, the gas velocity at the throat of the critical flow Venturi nozzle 1 increases with the increase of the pressure difference between the upstream and downstream sides. When the pressure difference between the upstream and downstream sides reaches the back pressure ratio, the natural gas velocity flowing through the throat of the critical flow Venturi nozzle 1 reaches its maximum velocity, i.e., the local speed of sound, which is called the critical flow state. The back pressure ratio detection and control system collects the pressure difference between the upstream and downstream sides of the nozzle. By consulting the pressure difference and back pressure ratio correspondence table, it determines whether the back pressure ratio between the upstream and downstream sides of the critical flow Venturi nozzle 1 has been reached, thereby judging whether the airflow at the nozzle throat has reached the critical flow state. Overall, the structural design is simple and reasonable, and it can effectively monitor the pressure difference before and after the critical flow Venturi nozzle, judge whether the nozzle throat has reached the critical flow state, and effectively improve the reliability of the critical flow Venturi nozzle method gas flow standard device.

[0026] The critical flow Venturi nozzle back pressure ratio detection device of this embodiment includes at least the following two structural forms:

[0027] 1) such as Figure 1 As shown, the back pressure ratio detection and control system includes a differential pressure transmitter 3, and pipelines are connected to the two detection points respectively. The pipelines are connected to the inlet of the differential pressure transmitter 3.

[0028] In the above scheme 1), a differential pressure transmitter 3 is used to monitor the pressure difference between the upstream and downstream of the critical flow Venturi nozzle 1 in real time and effectively. Then, by consulting the pressure difference and back pressure ratio correspondence table, it is determined whether the back pressure ratio between the upstream and downstream of the critical flow Venturi nozzle 1 has been reached, thereby determining whether the airflow at the nozzle throat has reached the critical flow state.

[0029] In a preferred embodiment, the differential pressure transmitter 3 is connected to the background intelligent terminal b via a first communication device a.

[0030] In the above implementation scheme, the differential pressure transmitter 3 is connected to the back-end intelligent terminal network, which can feed back the measured pressure difference data to the back-end in real time. The back-end intelligent terminal can then automatically compare it with the back pressure ratio and intelligently determine whether the back pressure ratio has been reached upstream and downstream of the critical flow venturi nozzle 1. Furthermore, it allows back-end staff to be aware of the test results in real time.

[0031] In the embodiment, the first communication device can be a conventional 4G / 5G communication device on the market, which can realize stable remote data transmission.

[0032] 2) As shown in Figure 2 The back pressure ratio detection control system includes a processor c and two pressure detectors 4. The two pressure detectors 4 are respectively arranged at two detection points for detecting the pressure values upstream and downstream of the critical flow Venturi nozzle 1. The pressure detectors 4 are respectively connected to the processor.

[0033] In the second scheme, the two pressure detectors 4 are used to detect the pressure data upstream and downstream of the critical flow Venturi nozzle 1, and the data is fed back to the processor in real time. According to the pressure values upstream and downstream, the pressure difference can be accurately calculated, and then compared with the back pressure ratio table to determine whether the upstream and downstream of the critical flow Venturi nozzle 1 reaches the back pressure ratio, so as to determine whether the gas flow in the nozzle throat reaches the critical flow state.

[0034] In the embodiment, the pressure detector 4 can be an electronic pressure gauge of a suitable model on the market.

[0035] As a preferred embodiment, the processor is connected to the background intelligent terminal network through the second communication device d.

[0036] In the embodiment, the two pressure detectors 4 are connected to the background intelligent terminal network, so that the measured pressure difference data can be fed back to the background in real time. The background intelligent terminal can calculate the difference between the two groups of pressure, that is, the pressure difference upstream and downstream of the critical flow Venturi nozzle 1, and automatically compare the obtained pressure difference value with the back pressure ratio, intelligently determine whether the upstream and downstream of the critical flow Venturi nozzle 1 reaches the back pressure ratio. Moreover, the staff of the background can know the detection result in real time.

[0037] In the embodiment, the second communication device can be a conventional 4G / 5G communication device on the market, which can realize stable remote data transmission.

[0038] As a preferred embodiment, a switch valve e is arranged downstream of the detection pipeline 2.

[0039] In the embodiment, the switch valve can control the on-off state of the fluid in the detection pipeline 2.

[0040] The switch valve can be an electrically controlled valve connected to the controller.

[0041] In the embodiment, if necessary, a flow valve can be arranged on the detection pipeline 2 to adjust the flow rate of the fluid in the pipeline.

[0042] As a preferred embodiment, as shown in Figure 3 The upstream of the detection pipeline 2 is connected in series with a pipe bundle rectifier 5.

[0043] In the above embodiment, the pipe bundle rectifier 5 is added for the purpose of rectifying the flow into the detection pipeline 2.

[0044] In the present embodiment, the pipe bundle rectifier 5 is a prior art, and an appropriate model can be used according to the field use requirement, which will not be described here.

[0045] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0046] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0047] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicate that the first feature is higher than the second feature in horizontal height. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicate that the first feature is lower than the second feature in horizontal height.

[0049] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0050] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A device for detecting back pressure ratio in a critical flow venturi nozzle, characterized by: Critical flow Venturi nozzle (1), detection pipeline (2) and back pressure ratio detection control system are included, the critical flow Venturi nozzle (1) is communicated and is arranged on the detection pipeline (2), the detection pipeline (2) is equipped with detection point respectively at both ends of the critical flow Venturi nozzle (1), and the back pressure ratio detection control system is used to collect the pressure difference of two detection points.

2. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 1, characterized in that: The back pressure ratio detection control system includes a differential pressure transmitter (3), and pipelines are connected to the two detection points respectively, and the pipelines are connected to the inlet of the differential pressure transmitter (3).

3. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 2, characterized in that: The differential pressure transmitter (3) is connected to a background intelligent terminal network through a first communication device.

4. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 3, characterized in that: The first communication device is a 4G / 5G communication device.

5. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 1, characterized in that: The back pressure ratio detection control system includes a processor and two pressure detectors (4), the two pressure detectors (4) are respectively installed at the two detection points, and are respectively used to detect the pressure values of the upstream and downstream of the critical flow Venturi nozzle (1), and the pressure detectors (4) are connected to the processor respectively.

6. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 5, characterized in that: The pressure detector (4) is an electronic pressure gauge.

7. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 5, characterized in that: The processor is connected to a background intelligent terminal network through a second communication device.

8. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to claim 7, characterized in that: The second communication device is a 4G / 5G communication device.

9. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to any one of claims 1 to 8, characterized in that: A switch valve is arranged downstream of the detection pipeline (2).

10. A device for detecting the back pressure ratio of a critical flow Venturi nozzle according to any one of claims 1 to 8, characterized in that: A pipe bundle rectifier (5) is connected in series upstream of the detection pipeline (2).

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