A vacuum pump exhaust volume measurement system, vacuum pump and vacuum system

Abstract

The present application provides a vacuum pump exhaust volume measurement system, a vacuum pump and a vacuum system, which are used to conveniently and accurately measure the vacuum pump exhaust volume on site. The vacuum pump exhaust volume measurement system provided by the present application includes an exhaust pipe of a vacuum pump, a measuring pipe and a gas flow meter; the measuring pipe is led out from the exhaust pipe, the exhaust pipe is provided with a first valve after the interface position of the measuring pipe, the measuring pipe is provided with a second valve, and the measuring pipe is provided with a gas flow meter after the second valve. By leading the measuring pipe out from the exhaust pipe of the vacuum pump, and adjusting the on-off state of the first valve on the exhaust pipe and the second valve on the measuring pipe, the vacuum pump exhaust volume is measured by the gas flow meter in the measuring pipe. This setting can not only ensure the normal exhaust of the vacuum pump, but also avoid the risk of large exhaust pipe resistance and blockage in the prior art, and bring the advantages of high measurement accuracy, convenient manual operation and low economic cost.

Description

Technical Field

[0001] The present application relates to the field of vacuum, and in particular to a vacuum pump exhaust volume measurement system, a vacuum pump and a vacuum system. Background Art

[0002] Steam turbines are one of the main equipment in the power generation process, and a certain vacuum must be maintained during their operation. A decrease in the vacuum of the steam turbine will cause: (1) The exhaust temperature rises, the low-pressure cylinder expands unevenly and is prone to vibration, and in severe cases, dynamic and static friction; (2) The exhaust temperature rises, the heat carried away by the cooling water increases, the cold source loss increases, and the operation is uneconomical; (3) The exhaust temperature rises, the expansion of the condenser cooling water pipe is prone to loosening and leaking, and the tightness is destroyed; (4) In order to maintain the unit load unchanged, the air intake needs to be increased, the last stage blades may be overloaded, and the axial displacement of the impulse turbine increases; (5) The specific volume of steam decreases, the flow rate decreases, and the last few stages are prone to blade flutter, which is very harmful to the blades. Therefore, a decrease in the vacuum of the steam turbine seriously affects its safe and economical operation.

[0003] The vacuum pump and the complete set of units continuously extract the non-condensable gases leaking in from different ways from the turbine and condenser to establish and maintain the turbine vacuum. The vacuum pump's suction volume can directly reflect the vacuum degree of the unit, so the vacuum pump's suction volume needs to be measured on site. At present, there are only clear regulations for measuring the vacuum pump's suction volume in the laboratory at home and abroad, using fixed orifice plates or metering nozzles, but such measuring devices cannot be used on site.

[0004] Most of the methods for measuring the suction volume of the on-site vacuum pump are measured on the outlet pipeline of the suction equipment, which can be divided into direct measurement method and indirect measurement method. The direct measurement method has low measurement accuracy due to the low air flow rate of the vacuum pump. The indirect measurement method installs the measuring device on the small-diameter exhaust pipe of the vacuum pump. The smaller the pipe diameter, the greater the pipe resistance, which makes it easy for the air in the gas-water separator to be unable to be discharged normally. In severe cases, it directly affects the performance of the suction equipment and the condenser pressure. In addition, the existing flow meter is prone to blockage due to design defects.

[0005] Therefore, the defects of the existing vacuum pump exhaust volume measurement method, such as those mentioned above, need to be solved urgently. Summary of the invention

[0006] The present application provides a vacuum pump exhaust volume measurement system, a vacuum pump and a vacuum system, which are used to conveniently and accurately measure the exhaust volume of the vacuum pump on site.

[0007] In a first aspect, the present application provides a vacuum pump exhaust volume measurement system, the vacuum pump exhaust volume measurement system comprising an exhaust pipe of the vacuum pump, a measurement pipe and a gas flow meter;

[0008] The measuring pipeline is led out from the exhaust pipeline, the exhaust pipeline is provided with a first valve after the interface position of the measuring pipeline, the measuring pipeline is provided with a second valve, and the measuring pipeline is provided with a gas flow meter after the second valve.

[0009] In combination with the first aspect of the present application, in a first possible implementation of the first aspect of the present application, the gas flow meter is a Verabar flow meter.

[0010] In combination with the first possible implementation of the first aspect of the present application, in a second possible implementation of the first aspect of the present application, if the measuring pipeline is arranged horizontally, the first direction of the Verabar flowmeter is tilted downward by 10 to 90 degrees, and the first direction is the lead-out direction of the sensor of the Verabar flowmeter; or,

[0011] If the measuring pipeline is arranged vertically, the first direction is inclined downward by 0 to 5 degrees.

[0012] In combination with the first possible implementation of the first aspect of the present application, in a third possible implementation of the first aspect of the present application, the insertion depth of the sensor of the Verabar flowmeter is not less than 2 / 3 of the diameter of the measuring pipe.

[0013] In combination with the first possible implementation of the first aspect of the present application, in a fourth possible implementation of the first aspect of the present application, the Verabar flowmeter includes a differential pressure transmitter, and the arrangement height of the differential pressure transmitter is higher than the sensor of the Verabar flowmeter.

[0014] In combination with the first aspect of the present application, in a fifth possible implementation of the first aspect of the present application, the distance between the second valve and the interface position is 0.5 m, and the distance between the second valve and the gas flow meter is 1 m.

[0015] In combination with the first aspect of the present application, in a sixth possible implementation of the first aspect of the present application, the exhaust pipe is provided with a three-way pipe fitting, and the measuring pipe is led out from the exhaust pipe through the three-way pipe fitting.

[0016] In combination with the first aspect of the present application, in a seventh possible implementation of the first aspect of the present application, the first valve and the second valve are both stop valves.

[0017] In a second aspect, the present application provides a vacuum pump, which includes the vacuum pump air extraction volume measurement system described in the first aspect of the present application or any possible implementation of the first aspect.

[0018] In a third aspect, the present application provides a vacuum system, wherein the vacuum system comprises the vacuum pump described in the second aspect of the present application.

[0019] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0020] The vacuum pump exhaust volume measurement system provided by the present application leads out a measuring pipe on the exhaust pipe of the vacuum pump, and adjusts the on-off state of the first valve on the exhaust pipe and the second valve on the measuring pipe, and measures the exhaust volume of the vacuum pump by a gas flow meter in the measuring pipe. This setting can not only ensure the normal exhaust of the vacuum pump, but also avoid the risks of large exhaust pipe resistance and blockage in the prior art, and bring the advantages of high measurement accuracy, convenient manual operation and low economic cost, but also bring the advantages of low pressure loss, maintenance cost approaching zero, and convenient online installation and maintenance. Therefore, in on-site production practice, the vacuum pump exhaust volume measurement system provided by the present application has high application value and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of an embodiment of a vacuum pump exhaust volume measurement system in the present application;

[0022] Figure 2 A schematic diagram of an embodiment of the Verabar flowmeter in the present application;

[0023] Figure 3 This is a schematic diagram of an assembly of the Verabar flowmeter in this application;

[0024] Figure 4 Another assembly diagram of the Verabar flowmeter in this application;

[0025] Figure 5 This is another assembly diagram of the Verabar flowmeter in this application;

[0026] Figure 6 This is another assembly diagram of the Verabar flowmeter in this application. DETAILED DESCRIPTION

[0027] The present application provides a vacuum pump exhaust volume measurement system, a vacuum pump and a vacuum system, which are used to conveniently and accurately measure the exhaust volume of the vacuum pump on site.

[0028] First, see Figure 1 The schematic diagram of an embodiment of a vacuum pump exhaust volume measurement system is shown. In the system, an exhaust pipe 110 of a vacuum pump 100 , a measurement pipe 120 and a gas flow meter 130 are included.

[0029] It can be understood that the exhaust duct 110 is used to exhaust the air exhausted when the vacuum pump 100 is evacuated. The exhaust duct 110 can be a duct formed by extending the shell of the vacuum pump 100 itself, or it can also be a duct additionally configured for the vacuum pump 100. In order to cooperate with the vacuum pump 100 in different application scenarios, the staff can configure different exhaust ducts 110 to facilitate the on-site layout of the exhaust duct 100.

[0030] The measuring pipeline 120 is led out from the exhaust pipeline 100. The exhaust pipeline 110 is provided with a first valve 111 after the interface position S of the measuring pipeline 120. The first valve 111 is used to control the on-off state of the exhaust pipeline 100 after the interface position S of the measuring pipeline 120. The measuring pipeline 120 is provided with a second valve 121. The second valve 121 is used to control the on-off state of the measuring pipeline 120 after the second valve 121. The measuring pipeline 120 is also provided with a gas flowmeter 130 after the second valve 121.

[0031] In this application, the normal working state of the vacuum pump exhaust volume measurement system can be divided into the following two stages:

[0032] (1) Measurement phase

[0033] In this stage, the first valve 111 is in the off state, and the second valve 121 is in the on state. At this time, the gas exhausted by the vacuum pump 100 is discharged through the measuring pipe 120. In this process, the gas flow meter 130 can measure the gas flow rate, determine the specific parameters of the vacuum pump exhaust volume, and output the vacuum pump exhaust volume to the relevant processing equipment;

[0034] (2) Normal exhaust stage

[0035] In this stage, the first valve 111 is in the on state, and the second valve 121 is in the off state, and the gas exhausted by the vacuum pump 100 is normally discharged through the exhaust pipe 110. The exhaust pipe 110 can also be connected to an external device such as a muffler to further reduce the noise of the gas exhausted by the exhaust pipe 110.

[0036] From the above, it can be seen that the vacuum pump exhaust volume measurement system provided by the present application, by leading out a measuring pipe 120 on the exhaust pipe 110 of the vacuum pump 100, and adjusting the on-off state of the first valve 111 on the exhaust pipe 110 and the second valve 121 on the measuring pipe 120, the vacuum pump exhaust volume is measured by the gas flow meter 130 in the measuring pipe 120. This setting can not only ensure the normal exhaust of the vacuum pump 100, but also avoid the risk of high resistance and blockage of the exhaust pipe 110 in the prior art, and bring the advantages of high measurement accuracy, convenient manual operation and low economic cost, but also bring the advantages of low pressure loss, maintenance cost approaching zero, and convenient online installation and maintenance. Therefore, in on-site production practice, the vacuum pump exhaust volume measurement system provided by the present application has high application value and promotion value.

[0037] In order to further understand the present application, various optimization methods of the present application in practical applications will be further introduced below.

[0038] For example, in practical applications, the gas flow meter 130 may specifically adopt different types of gas flow meters such as a target flow meter, a V-cone flow meter, a vortex flow meter, an orifice flow meter or a Verabar flow meter.

[0039] Among them, the following content of this application takes the Willabar flowmeter as an example. The Willabar flowmeter is a differential pressure, rate averaging gas flowmeter. It measures the flow rate through the differential pressure generated by the sensor in the gas in the measuring pipe 120. It can output a very stable, pulsation-free differential pressure signal, and determine the vacuum pump suction volume based on the differential pressure signal. It has the advantages of being relatively stable and highly accurate.

[0040] For details, please refer to Figure 2 A schematic diagram of an embodiment of a Verabar flowmeter is shown, in which the sensor can produce accurate pressure distribution and a fixed gas separation point; the low-pressure pressure holes located on both sides of the rear of the sensor and before the gas separation point can generate a stable differential pressure signal, effectively prevent blockage and maintain long-term high accuracy.

[0041] The gas discharged by the vacuum pump 100 through the measuring pipe 120 generates a high-pressure distribution area in front of the sensor of the Verabar flowmeter, and the pressure of the high-pressure distribution area is slightly higher than the static pressure of the measuring pipe 120. According to the Bernoulli equation, the gas speeds up when flowing through the sensor, and a low-pressure distribution area is generated at the rear of the sensor, and the pressure of the low-pressure distribution area is slightly lower than the static pressure of the pipe. The sensor has multiple pairs (usually three pairs) of pressure holes arranged according to certain rules in the high and low pressure distribution areas, which respectively measure the total pressure of the gas, including the average velocity pressure P1 and the static pressure P2. P1 and P2 are respectively introduced into the differential pressure transmitter to measure the differential pressure △P=P1-P2. △P is used to indicate the size of the average velocity of the gas, so that the flow rate of the gas can be calculated, thereby determining the vacuum pump suction volume. Among them, the multiple pairs of pressure holes set on the sensor can effectively maintain the stable and high-precision measurement effect of the Verabar flowmeter.

[0042] Further, combined with Figure 3 and Figure 4 The following are schematic diagrams of the assembly of the Verabar flowmeter. The installation method of the Verabar flowmeter can be as follows:

[0043] (1) First, determine the installation location and direction according to the installation requirements of the Verabar flowmeter and the type of measured medium;

[0044] (2) Welding the base to a designated position of the measuring pipe 120;

[0045] (3) rotating the handle of the online hole-drilling tool to allow the hole-drilling head to drill into the wall of the measuring pipe 120 and perform hole-drilling, so that the hole-drilling head completely penetrates the wall of the measuring pipe 120;

[0046] (5) Rotate the handle in the opposite direction to retract the drilling head and remove the online drilling tool;

[0047] (6) Connect the Verabar flowmeter, calibrate the flow-facing surface of the sensor of the Verabar flowmeter, rotate the drive rod so that the sensor of the Verabar flowmeter is inserted to the required depth of the measuring pipe 120, and lock the screws and nuts.

[0048] Furthermore, the Verabar flowmeter can be connected to a display, and the measurement result of the vacuum pump's exhaust volume can be directly displayed to the user through the display, so that the user can intuitively know it, and can judge the vacuum state of the steam turbine based on the operating experience and historical data, manually adjust the operating power of the vacuum pump 100, or perform related processing;

[0049] Alternatively, the Verabar flowmeter can also be connected to relevant processing equipment and send the measurement results of the vacuum pump's suction volume, for example, it can be sent to a programmable logic controller (PLC) program control system in the vacuum system. The PLC program control system can automatically adjust the operating power of the vacuum pump 100 according to the measurement results of the vacuum pump's suction volume.

[0050] Furthermore, as the vacuum pump 100 and / or the exhaust pipe 110 are arranged in the field environment, the measuring pipe 120 can be divided into two settings:

[0051] (1) Horizontal setting

[0052] If the measuring pipe 120 is arranged horizontally, Figure 5 Another assembly schematic diagram of the Verabar flowmeter is shown, in which the first direction of the Verabar flowmeter is tilted downward by 10 to 90 degrees, wherein the first direction is the lead-out direction of the sensor of the Verabar flowmeter.

[0053] (2) Vertical setting

[0054] If the measuring pipe 120 is arranged vertically, Figure 6 Another schematic diagram of the assembly of the Verabar flowmeter is shown, in which the first direction of the Verabar flowmeter is tilted downward by 0 to 5 degrees.

[0055] Through the above arrangement, if the gas discharged by the vacuum pump 100 contains a little moisture, it can slide down and leave the sensor after accumulating on the surface of the sensor, thereby preventing the moisture in the gas from affecting the operation of the sensor and further ensuring the accuracy of the measurement of the Verabar flowmeter.

[0056] Furthermore, the insertion depth of the sensor of the Verabar flowmeter is not less than 2 / 3 of the diameter of the measuring pipe 120 to ensure a larger contact area between the sensor and the gas in the measuring pipe 120, so that the measured total pressure of the gas can effectively reflect the characteristics of the gas and ensure the accuracy of the Verabar flowmeter measurement.

[0057] Furthermore, the Verabar flowmeter includes a differential pressure transmitter, and the differential pressure transmitter is arranged at a higher height than the sensor of the Verabar flowmeter to ensure the accuracy of the differential pressure signal, thereby further ensuring the accuracy of the measurement of the Verabar flowmeter.

[0058] Furthermore, the distance between the second valve 121 and the interface position S is 0.5m, and the distance between the second valve 121 and the gas flow meter 130 is 1m. Under this distance setting, the gas discharged from the vacuum pump 100 can flow smoothly when the first valve 111 and the second valve 121 are switched on and off, and is not prone to blockage, thereby ensuring the normal operation of the exhaust work of the vacuum pump 100.

[0059] Furthermore, the measuring pipe 120 can not only be directly led out of the exhaust pipe 110 by welding or the like, but the exhaust pipe 110 can also be provided with connecting components such as tee fittings, and the measuring pipe 120 is led out of the exhaust pipe 110 through connecting components such as tee fittings. Through the provision of connecting components, not only is the installation of the measuring pipe 120 easy and has high stability, but it is also easy to disassemble the measuring pipe 120, thereby facilitating the replacement or disassembly and cleaning of the exhaust pipe 110 and / or the measuring pipe 120.

[0060] Furthermore, the first valve 111 and the second valve 121 can be valves of the type of gate valves, stop valves, ball valves, butterfly valves, etc. Preferably, stop valves are used. Stop valves have the advantages of low friction, durability, small opening height, easy manufacturing, and convenient maintenance. They are not only suitable for medium and low pressures, but also for high pressures.

[0061] It is understood that the present application also provides a vacuum pump 100, and the vacuum pump 100 includes the vacuum pump exhaust volume measurement system described above. The vacuum pump 100 can be divided into a gas delivery pump and a gas capture pump according to different types. Specifically, different types can be further subdivided according to different application environments and principles, which are not specifically limited here.

[0062] In addition, the present application also provides a vacuum system, which includes the vacuum pump introduced above, and the vacuum system also includes a PLC program control system, a gas storage tank, a vacuum pipe, a vacuum valve and other components and / or equipment. Under the control of the PLC program control system, a stable vacuum source is provided to meet production needs, and the system can be widely used in the electronic semiconductor industry, optoelectronic backlight module or mechanical processing industries.

[0063] To summarize, the vacuum pump exhaust volume measurement system, vacuum pump and vacuum system provided in the present application, by leading out a measuring pipe 120 on the exhaust pipe 110 of the vacuum pump 100, and adjusting the on-off state of the first valve 111 on the exhaust pipe 110 and the second valve 121 on the measuring pipe 120, the vacuum pump exhaust volume is measured by a gas flow meter 130 in the measuring pipe 120. This setting can not only ensure the normal exhaust of the vacuum pump 100, but also avoid the risks of high resistance and blockage of the exhaust pipe 110 in the prior art, and bring the advantages of high measurement accuracy, convenient manual operation and low economic cost, but also bring the advantages of low pressure loss, maintenance cost approaching zero, and convenient online installation and maintenance. Therefore, in on-site production practice, the vacuum pump exhaust volume measurement system provided by the present application has high application value and promotion value.

[0064] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A vacuum pump exhaust volume measurement system, characterized in that: The vacuum pump exhaust volume measurement system comprises an exhaust pipe of the vacuum pump, a measuring pipe and a gas flow meter; The measuring pipeline is led out from the exhaust pipeline, the exhaust pipeline is provided with a first valve after the interface position of the measuring pipeline, the measuring pipeline is provided with a second valve, and the measuring pipeline is provided with the gas flow meter after the second valve; Wherein, the working state of the vacuum pump exhaust volume measurement system includes a measurement phase and a normal exhaust phase; When the working state of the vacuum pump exhaust volume measurement system is the measurement stage, the first valve is in the closed state, and the second valve is in the on state; When the working state of the vacuum pump exhaust volume measurement system is the normal exhaust stage, the first valve is in an on state, and the second valve is in an off state; Wherein, the gas flow meter is a Verabar flow meter; If the measuring pipeline is arranged horizontally, the first direction of the Verabar flowmeter is inclined downward by 10 to 90 degrees, and the first direction is the lead-out direction of the sensor of the Verabar flowmeter; or, If the measuring pipe is arranged vertically, the first direction is inclined downward by 0 to 5 degrees.

2. The vacuum pump exhaust volume measurement system according to claim 1, characterized in that: The insertion depth of the sensor of the Verabar flowmeter is not less than 2 / 3 of the diameter of the measuring pipe.

3. The vacuum pump exhaust volume measurement system according to claim 1, characterized in that: The Verabar flowmeter includes a differential pressure transmitter, and the differential pressure transmitter is arranged at a higher height than the sensor of the Verabar flowmeter.

4. The vacuum pump exhaust volume measurement system according to claim 1, characterized in that: The distance between the second valve and the interface position is 0.5 m, and the distance between the second valve and the gas flow meter is 1 m.

5. The vacuum pump exhaust volume measurement system according to claim 1, characterized in that: The exhaust pipe is provided with a three-way pipe fitting, and the measuring pipe is led out from the exhaust pipe through the three-way pipe fitting.

6. The vacuum pump exhaust volume measurement system according to claim 1, characterized in that: The first valve and the second valve are both stop valves.

7. A vacuum pump, characterized in that: The vacuum pump comprises the vacuum pump exhaust volume measurement system according to any one of claims 1 to 6.

8. A vacuum system, characterized in that: The vacuum system comprises the vacuum pump of claim 7.

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