A fluid leak detector and method of detection

Abstract

The application provides a fluid leakage amount detector and a detection method. The detector comprises a cylinder, a piston, a displacement sensor and a central processing unit for calculating the fluid leakage amount according to the displacement amount of the piston. The piston is located in the cylinder and separates the inner cavity of the cylinder into a first cavity and a second cavity. The first cavity is communicated with a fluid pipeline to be detected through a transmission pipeline. The first cavity is used for collecting the fluid leaked from the fluid pipeline to be detected. The displacement sensor is connected with the tail end of the piston. The central processing unit is electrically connected with the displacement sensor. The displacement sensor detects the moving distance of the piston, and the central processing unit obtains the fluid leakage amount according to the moving distance of the piston. The application can be used for detecting the sealing performance of a valve body device, solves the problem that the conventional flow meter cannot be used to detect the micro leakage amount of the fluid in the device, and can recycle the fluid leaked from the device into a fluid collecting box by means of peripheral equipment, so as to prevent the pollution to the environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluid leakage detection, and particularly relates to a fluid leakage amount detector and a detection method. BACKGROUND

[0002] At present, when the fluid (such as water, oil, etc.) leakage amount is detected, a flowmeter is generally used when the fluid flow rate is large. However, when the fluid has intermittent leakage and the flow rate is extremely small, or even dripping, the fluid cannot drive the internal components of the flowmeter to rotate, so that the flowmeter cannot give an accurate detection result. The current popular fluid leakage detection method is to directly measure the leaked medium by using a measuring cup. However, this manual measurement method is very inconvenient to operate, and when the leakage amount is large, the measuring cup is full and spills, which can cause pollution to the human body and the surrounding environment.

[0003] Therefore, how to accurately measure the leakage amount when the fluid has intermittent leakage and the flow rate is extremely small, or even dripping, and improve the automation degree of detection and prevent pollution of the environment is a technical problem to be solved at present. SUMMARY

[0004] The purpose of the present application is to provide a fluid leakage amount detector and a detection method, which accurately measure the leakage amount when the fluid has intermittent leakage and the flow rate is extremely small, or even dripping, and improve the automation degree of detection and prevent pollution of the environment.

[0005] To achieve the above purpose, the present application provides a fluid leakage amount detector, which comprises a cylinder body, a piston, a displacement sensor and a central processing unit for calculating the fluid leakage amount according to the displacement amount of the piston; the piston is located in the cylinder body and separates the inner cavity of the cylinder body into a first cavity and a second cavity; the first cavity is communicated with a fluid pipeline to be detected through a transmission pipeline; the displacement sensor is connected with the tail end of the piston; and the central processing unit is electrically connected with the displacement sensor.

[0006] As above, wherein a control valve is installed on the transmission pipeline through which the first cavity is connected with the fluid pipeline to be detected.

[0007] As above, wherein the control valve is an electromagnetic control valve which is electrically connected with the central processing unit.

[0008] As above, wherein the displacement sensor is a grating displacement sensor, and the scale grating of the grating displacement sensor is fixedly connected with the tail end of the piston.

[0009] As above, wherein the cylinder body further has a through-length piston guide rod which is fixed in the cylinder body along the moving direction of the piston, the piston is sleeved on the outside of the piston guide rod, and the piston is in sliding connection with the piston guide rod.

[0010] The initial position of the piston is located at the side of the first cavity connected to the fluid pipeline to be detected, and the piston moves in the direction of the second cavity until the space of the second cavity disappears under the increase of the fluid in the first cavity.

[0011] The fluid leakage amount detector further comprises a fluid collection tank, the fluid collection tank is communicated with the first cavity through a recovery pipeline when the space of the second cavity disappears, and the fluid collection tank is communicated with the second cavity through the recovery pipeline when the space of the second cavity does not disappear.

[0012] The cylinder has an opening part at the end close to the second cavity, the piston is fixed with a piston rod at the side close to the second cavity, the piston rod is arranged in the moving direction of the piston, the piston rod passes out of the opening part, and the end of the piston rod away from the piston is fixedly connected with the displacement sensor.

[0013] The piston rod is hollow, and the piston guide rod passes into the hollow of the piston rod.

[0014] The grating displacement sensor comprises a light receiving element, the light receiving element is arranged at the side of the cylinder in parallel to the moving direction of the piston, and the central processing unit is electrically connected with the light receiving element.

[0015] The application has the following beneficial effects:

[0016] (1) The application drives the piston to move by using the fluid pressure itself, the displacement sensor detects the displacement of the piston, and the fluid micro-leakage amount is calculated according to the piston displacement amount and the piston cross-sectional area, so that the automation degree is high and the detection accuracy is high, and the micro-leakage amount of the pipeline to be detected can be measured.

[0017] (2) The application avoids the situation that the detection process cannot be controlled and continued due to the "spray leakage" caused by the sudden failure of the measured equipment, and the fluid leaked from the equipment can be recovered into the oil tank by means of the peripheral equipment, so as to reduce the pollution to the detection environment. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only some embodiments of the application, and other drawings can be obtained by those skilled in the art according to these drawings.

[0019] Figure 1This is a schematic diagram of the structure of a fluid leakage detector according to an embodiment of this application.

[0020] Figure 2 This is a side view of the piston and piston guide rod according to an embodiment of this application.

[0021] Reference numerals: 1-Cylinder; 2-Piston; 3-Displacement sensor; 4-Control valve; 5-Central processing unit; 6-Fluid collection tank; 11-First chamber; 12-Second chamber; 21-Piston guide rod; 22-Piston rod; 31-Scale grating; 32-Light receiving element; 61-Recovery pipeline. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] Example 1

[0024] like Figure 1 As shown, this application provides a fluid leakage detector, including a cylinder 1, a piston 2, a displacement sensor 3, and a central processing unit 5 for calculating the fluid leakage based on the displacement of the piston 2; the cylinder 1 is cylindrical, the piston 2 is located inside the cylinder 1, and the inner cavity of the cylinder 1 is divided into a first cavity 11 and a second cavity 12; the first cavity 11 is connected to the fluid pipeline to be detected through a transmission pipeline; the displacement sensor 3 is connected to the tail end of the piston 2; the central processing unit 5 is electrically connected to the displacement sensor 3.

[0025] As a specific embodiment of the present invention, when detecting fluid leakage, the first cavity 11 is connected to the fluid pipeline to be detected through a transmission pipeline. The fluid with leakage in the fluid pipeline to be detected flows into the first cavity 11 through the transmission pipeline. As the fluid in the first cavity 11 increases, under the pressure of the fluid, the piston 2 moves towards the second cavity 12. The displacement sensor 3 senses the amount of movement of the piston 2. The central processing unit 5 collects the displacement of the piston 2 sensed by the displacement sensor 3 and calculates the micro-leakage of the fluid based on the displacement of the piston 2 and the cross-sectional area of ​​the piston 2, thereby accurately detecting the micro-leakage of the fluid pipeline to be detected.

[0026] like Figure 1 As shown, a control valve 4 is installed on the transmission pipeline connecting the first chamber 11 to the fluid to be tested. In this embodiment, the first chamber 11 is mainly used to receive leaked fluid. When there is a slight leak, the leaked fluid pushes the piston 2 towards the second chamber 12. The control valve 4 is used to open or block the passage of leaked fluid to the first chamber 11.

[0027] Preferably, the control valve 4 is an electromagnetic control valve electrically connected with the central processing unit 5. The electromagnetic control valve is opened or closed according to the electrical signal of the central processing unit 5, so as to realize opening or blocking the passage of the leakage fluid to the first cavity 11.

[0028] Preferably, the displacement sensor 3 is a grating displacement sensor, and a scale grating 31 of the grating displacement sensor is fixedly connected with the tail end of the piston 2. The grating displacement sensor is used for measuring the displacement of the piston 2. When the piston 2 moves in the direction of the second cavity 12 under the pressure of the leakage fluid, the piston 2 drives the scale grating 31 to move synchronously, so that the displacement of the piston 2 can be obtained by measuring the displacement of the scale grating 31.

[0029] As shown in Figure 1 , the cylinder 1 further has a through-length piston guide rod 21 fixed in the cylinder 1 along the moving direction of the piston 2, the piston 2 is sleeved outside the piston guide rod 21, and the piston 2 is in sliding connection with the piston guide rod 21. The piston guide rod 21 guides the moving direction of the piston 2, so as to facilitate more accurate obtaining of the displacement of the piston 2.

[0030] As a specific embodiment of the present application, the initial position of the piston 2 is located at the side of the first cavity 11 connected with the fluid pipeline to be detected. Under the increase of the fluid in the first cavity 11, the piston 2 moves in the direction of the second cavity 12 until the space of the second cavity 12 disappears.

[0031] As shown in Figure 1 , the fluid leakage amount detector further comprises a fluid collection tank 6. When the space of the second cavity 12 disappears, the fluid collection tank 6 is communicated with the first cavity 11 through a recovery pipeline 61. When the space of the second cavity 12 does not disappear, the fluid collection tank 6 is communicated with the second cavity 12 through the recovery pipeline 61. When the detection is completed, the fluid in the cylinder 1 can be discharged into the fluid collection tank 6 through the recovery pipeline 61. Or when the fluid in the cylinder 1 fills the entire cylinder 1 and the space of the second cavity 12 disappears, the fluid can be discharged into the fluid collection tank 6 through the recovery pipeline 61, so as to avoid the fluid flowing into the surrounding environment and prevent pollution to the environment.

[0032] As shown in Figure 1 , the cylinder 1 has an opening portion at the end close to the second cavity 12, the piston 2 has a piston rod 22 fixed at the side close to the second cavity 12, the piston rod 22 is arranged along the moving direction of the piston 2, the piston rod 22 passes out from the opening portion, and the end of the piston rod 22 away from the piston 2 is fixedly connected with the displacement sensor 3.

[0033] As a specific embodiment of the present application, the piston rod 22 is hollow, and the piston guide rod 21 penetrates into the hollow of the piston rod 22. The piston 2 and the piston rod 22 are movable along the piston guide rod 21.

[0034] As shown in Figure 1 The grating displacement sensor includes a light receiving element 32 arranged on one side of the cylinder 1 in parallel to the moving direction of the piston 2, and the central processing unit 5 is electrically connected with the light receiving element 32. The light receiving element 32 is used to sense the displacement of the scale grating 31.

[0035] The central processing unit 5 includes a CPU, a signal conditioning circuit and a power supply, which are all prior art and will not be described here.

[0036] As a specific embodiment of the present application, the central processing unit 5 collects the first displacement of the piston 2 in a unit time, and takes the product of the first displacement and the cross-sectional area of the first cavity 11 as the fluid micro-leakage. The cross-sectional area of the first cavity 11 is the area of the piston 2 minus the cross-sectional area of the piston guide rod 21.

[0037] As a specific embodiment of the present application, the volume of the cylinder 1 is designed in association with the detection threshold. Specifically, the maximum flow of the fluid that the cylinder 1 can accommodate is equal to the size of the preset detection threshold. If the leakage of the fluid does not reach the threshold, the piston 2 will be automatically controlled to return to the initial position at the leftmost side of the cylinder 1 after the detection is completed. If the leakage of the fluid exceeds the threshold, the piston 2 has reached the rightmost side of the cylinder 1, and the leaked fluid flows back into the fluid collection tank 6 through the recovery pipeline 61.

[0038] As shown in Figure 2 The longitudinal cross-sectional shape of the piston 2 and the piston guide rod 21 is circular, Figure 2 Wherein, d1 represents the diameter of the piston 2; d2 represents the diameter of the piston guide rod 21. The central axis of the piston guide rod 21 and the central axis of the piston 2 are in the same straight line direction.

[0039] Embodiment two

[0040] A fluid leakage detection method using a fluid leakage detector, the detection method comprising the following steps:

[0041] The piston 2 is moved to the initial position, and the fluid pipeline to be detected is communicated with the first cavity 11 through the transmission pipeline;

[0042] The first cavity 11 collects the leaked fluid of the fluid pipeline to be detected; and the piston 2 moves away from the first cavity 11 as the fluid in the first cavity 11 increases;

[0043] The displacement sensor 3 collects the moving distance of the piston 2.

[0044] According to the moving distance of the piston 2, the integral calculation formula is used to calculate the fluid leakage amount in real time.

[0045] The integral calculation formula is as follows:

[0046] ;

[0047] The integral calculation formula is as follows: The integral symbol S represents the annular cross-sectional area between the piston 2 and the cylinder 1; dx represents the moving distance of the piston; d1 represents the diameter of the piston 2; and d2 represents the diameter of the piston guide rod 21.

[0048] The specific detection principle of the fluid leakage amount is as follows:

[0049] When starting detection, the piston 2 and the scale grating 31 are in the first position (i.e., the piston 2 is in the initial position), and when the system to be detected has leakage, the piston 2 will be pushed to move from left to right in the cylinder 1 along the piston guide rod 21. Assuming that the diameter of the piston 2 is d1 and the diameter of the piston guide rod 21 is d2, the cross-sectional area of the first cavity 11 is the annular cross-sectional area S between the piston 2 and the cylinder 1. The calculation method is as follows:

[0050] S = π × (d1 2 - d2 2 ) / 4.

[0051] Wherein, π is 3.14.

[0052] According to the integral concept, when the system has leakage, the piston 2 moves in the cylinder 1, driving the scale grating 31 to produce displacement, and the calculation method of the micro volume dv is as follows:

[0053] dv = S × dx.

[0054] Wherein, dx represents the moving distance of the piston; and dv represents the micro volume.

[0055] If the piston 2 moves in the cylinder 1 due to fluid leakage, the piston 2 and the scale grating 31 are both moved to the second position, and the total displacement p is generated from the first position (i.e., the piston 2 is in the initial position) to the second position. At this time, the calculation method of the total fluid leakage amount V is as follows:

[0056] ;

[0057] Wherein, The integral symbol represents.

[0058] The central processing unit 5 reads the displacement of the piston 2, and completes the above-mentioned calculations in the CPU of the central processing unit 5, and outputs and displays the calculation results.

[0059] When the fluid leakage amount detector detects the leakage amount of the fluid pipeline, as long as there is a slight leakage, the fluid pressure itself can drive the piston 2 to displace, and within a limited timing time, the fixed cross-sectional area between the piston 2 and the cylinder 1 and the relative displacement amount of the piston 2 are integrated and operated, so that the fluid leakage amount (volume) within the limited time can be obtained. The present application can be used for valve device sealing performance detection, and solves the problem that the conventional flow meter cannot detect the fluid micro-leakage amount in the device, and changes the traditional way of only using a measuring cup for detection and manual reading, and provides a technical means for automatic detection of the micro-leakage of the fluid in the device.

[0060] The beneficial effects achieved by the present application are as follows:

[0061] (1) The present application utilizes the fluid pressure itself to drive the piston to move, and the displacement sensor detects the piston displacement, so as to calculate the fluid micro-leakage amount according to the piston displacement amount and the piston cross-sectional area, and the degree of automation is high and the detection accuracy is high, and the micro-leakage amount of the pipeline to be detected can be measured.

[0062] (2) The present application avoids the situation that the detection process cannot be controlled and continued due to the "spray leakage" caused by the sudden failure of the measured device, and the fluid leaked from the device can be recycled into the oil tank by means of peripheral equipment, thereby reducing the pollution to the detection environment.

[0063] The above is only an embodiment of the present application and is not used to limit the present application. The present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of claims of the present application.

Claims

1. A fluid leak detector, characterized by, The fluid leakage detector comprises a cylinder, a piston, a displacement sensor and a central processing unit for calculating the fluid leakage amount according to the displacement of the piston. The piston is located in the cylinder and separates the inner cavity of the cylinder into a first cavity and a second cavity. The first cavity is communicated with the fluid pipeline to be detected through a transmission pipeline; and the first cavity is used for collecting the fluid leaked from the fluid pipeline to be detected. The displacement sensor is connected with the tail end of the piston; the displacement sensor is a grating displacement sensor; the scale grating of the grating displacement sensor is fixedly connected with the tail end of the piston; when the piston moves in the direction of the second cavity under the pressure of the leaked fluid, the piston drives the scale grating to move synchronously. The central processing unit is electrically connected with the displacement sensor. The initial position of the piston is located on the side of the first cavity connected with the fluid pipeline to be detected; when the fluid enters the first cavity, the piston moves in the direction of the second cavity until the space of the second cavity disappears; the displacement sensor detects the moving distance of the piston, and the central processing unit obtains the fluid leakage amount according to the moving distance of the piston. The fluid leakage detector further comprises a fluid collection tank. When the space of the second cavity disappears, the fluid collection tank is communicated with the first cavity through a recovery pipeline; when the space of the second cavity does not disappear, the fluid collection tank is communicated with the second cavity through the recovery pipeline. The maximum flow of the fluid that can be contained in the cylinder is equal to the preset detection threshold value; if the fluid leakage amount does not reach the threshold value, the piston is automatically controlled to be reset to the initial position on the left side of the cylinder after the detection is completed; if the fluid leakage amount exceeds the threshold value, the piston has reached the right side of the cylinder, and the leaked fluid flows back to the fluid collection tank through the recovery pipeline. The light receiving element of the grating displacement sensor is arranged on one side of the cylinder along the moving direction of the piston; the central processing unit is electrically connected with the light receiving element; when the piston moves in the direction of the second cavity under the pressure of the leaked fluid, the piston drives the scale grating to move synchronously, so that the displacement of the scale grating is sensed by the light receiving element, and the moving distance of the piston is obtained. The integral calculation formula is used to calculate the fluid leakage amount in real time according to the moving distance of the piston. The integral calculation formula is as follows: ； wherein V represents the total leakage amount of the fluid; represents an integral sign; S represents an annular cross-sectional area between the piston and the cylinder; dx represents a moving distance of the piston; d1 represents a diameter of the piston; and d2 represents a diameter of a piston guide rod. The fixed sectional area between the piston and the cylinder and the relative displacement of the piston are integrated within a limited timing time to obtain the fluid leakage amount within the limited time.

2. The fluid leak detector of claim 1, wherein, A control valve is installed on the transmission pipeline connected with the fluid pipeline to be detected; and the control valve controls the on-off of the transmission pipeline.

3. The fluid leak detector of claim 2, wherein, The control valve is an electromagnetic control valve electrically connected with the central processing unit.

4. The fluid leak detector of claim 1, wherein, The cylinder has an opening part on the side close to the second cavity; the piston has a piston rod fixed on the side close to the second cavity; the piston rod is arranged along the moving direction of the piston, and the piston rod penetrates out of the opening part; and the end of the piston rod away from the piston is fixedly connected with the displacement sensor.

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