Intelligent tank sampling system and method

Abstract

The present invention discloses an intelligent storage tank sampling system and method thereof. The intelligent storage tank sampling system includes a sampling valve, an electric pump, a sampling bottle, a sampling flow path, a sample recovery flow path and a PLC controller; under the control of the PLC controller, after the electromagnetic mechanism of the electric-controlled pneumatic valve is powered on, the pneumatic actuator rotates the valve core of the electric-controlled pneumatic valve under the action of compressed gas until the valve core is in a fully open position, and the samples at the preset sampling points in the storage tank flow into the sampling bottle through the sampling flow path and the electric-controlled pneumatic valve in turn; under the control of the PLC controller, the electromagnetic mechanism disconnects the power supply, and the pneumatic actuator drives the valve core to perform a reset operation until the valve core is in a fully closed position, cutting off the sample outlet of the sampling flow path; under the control of the PLC controller, the electric pump is turned on and off to replace and update the residual sample in the sample recovery flow path. Therefore, the present invention can improve the sampling efficiency and the authenticity of the sample data, and avoid accidents caused by manual sampling.

Description

Technical Field

[0001] The invention relates to an intelligent storage tank sampling system and a method thereof. Background Art

[0002] In order to monitor the status of liquid raw materials or products in storage tanks in real time during the production process, the petrochemical industry needs to collect a small amount of liquid from the tank for testing and analysis. The equipment specifically used to collect samples from the tank is called a tank sampler or tank sampling system.

[0003] Most of the tank sampling systems currently used are manual collection; the so-called manual collection means that all valves and pumps in the sampling system are in manual operation mode. When sampling, it is necessary to manually operate each valve and pump. Due to manual operation, the cycle time of the pump often cannot meet the requirements of completely replacing the residual sample, affecting the quality of sample collection.

[0004] This sampling method is relatively inefficient. In addition, during manual sampling, when the pipeline leaks, the sampling personnel may be injured by splashing liquid. Summary of the invention

[0005] The purpose of the present invention is to provide an intelligent tank sampling system and method thereof, which adopts a PLC controller for intelligent tank sampling, which can improve the sampling efficiency on the one hand, and on the other hand, can also improve the authenticity of sample data and avoid accidents caused by manual sampling.

[0006] In order to achieve the above technical objectives, the present invention will adopt the following technical solutions:

[0007] An intelligent tank sampling system includes a sampling valve, an electric pump, a sampling bottle, a sampling flow path, a sample recovery flow path and a PLC controller; the sampling valve is an electrically controlled pneumatic valve, and the electrically controlled pneumatic valve is provided with two normally open limit switches, corresponding to the first and second limit switches; wherein:

[0008] The electric-controlled pneumatic valve is a straight-through ball valve having two fluid interfaces, one of which is an injection port and the other is a sampling port; a pneumatic actuator and an electromagnetic mechanism are arranged on the valve body of the electric-controlled pneumatic valve;

[0009] One end of the sampling flow path is the injection end, and the other end is the sample outlet end; one end of the sample recovery flow path is the injection end, and the other end is the sample outlet end;

[0010] The sampling end of the sampling flow path is connected to a preset sampling point in the storage tank, the sampling end of the sample recovery flow path is connected to the storage tank, the sampling end of the sampling flow path is connected to the sampling port of the electric-controlled pneumatic valve after the confluence of the sampling end of the sample recovery flow path, and the sampling bottle is arranged below the sampling port of the electric-controlled pneumatic valve;

[0011] An electric pump is installed on the sample recovery flow path, and a one-way valve is provided between the electric pump and the injection end of the sample recovery flow path;

[0012] The electric-controlled pneumatic valve, the electric pump, and the limit switch are all electrically connected to the PLC controller through wires, and the first switch is connected in series to the wire between the PLC controller and the electric pump. At the same time, the electric-controlled pneumatic valve and the first switch are all signal-connected to the PLC controller through a signal transmission line;

[0013] Under the control of the PLC controller, after the electromagnetic mechanism of the electric-controlled pneumatic valve is powered on, the pneumatic actuator rotates the valve core of the electric-controlled pneumatic valve under the action of compressed gas until the valve core triggers the first limit switch and causes the first limit switch to close, indicating that the valve core of the electric-controlled pneumatic valve is in a fully open position, and the sample at the preset sampling point in the storage tank flows into the sampling bottle through the sampling flow path and the electric-controlled pneumatic valve in turn;

[0014] Under the control of the PLC controller, the electromagnetic mechanism disconnects the power supply, and the pneumatic actuator drives the valve core to perform the reset operation until the valve core triggers the second limit switch and causes the second limit switch to close, indicating that the valve core of the electric-controlled pneumatic valve is in a fully closed position, cutting off the sample outlet of the sampling flow path;

[0015] The first switch, under the control of the PLC controller, cuts off the power supply to the electric pump and stops the electric pump;

[0016] Under the control of the PLC controller, the first switch turns on the power supply of the electric pump, the electric pump runs, and the samples at the preset sampling points in the storage tank are returned to the storage tank through the sampling flow path and the sample recovery flow path in sequence, thereby realizing the replacement and update of the samples in the sampling flow path.

[0017] Preferably, the PLC controller includes a PLC main control chip, and the PLC main control chip includes a control module, a control panel and an indicator light group;

[0018] The control panel is provided with a button group, the button group includes a ready button; the indicator light group includes a ready indicator light;

[0019] The control module controls the on / off of the ready indicator light according to the state of the ready button.

[0020] Preferably, the button group includes a reset button; and the control module determines whether to control the electric-controlled pneumatic valve and the electric pump to reset according to the state of the reset button.

[0021] Preferably, the PLC main control chip is provided with a fault warning device, and the fault warning device includes a fault alarm indicator light and a fault alarm buzzer;

[0022] When the control module determines that the electric-controlled pneumatic valve has a fault, it triggers a fault alarm indicator light and a fault alarm buzzer.

[0023] Preferably, the button group includes a mute button; the mute button is connected to the control module;

[0024] The control module determines whether to control the fault alarm buzzer to stop sounding according to the state of the mute button.

[0025] Preferably, the button group includes an emergency stop button, and the emergency stop button is connected to the control module;

[0026] The control module determines whether to stop sampling, whether to control the electric-controlled pneumatic valve to perform a reset operation, and whether to extinguish the ready indicator light according to the state of the emergency stop button.

[0027] Preferably, the indicator light group includes a sampling completion indicator light and a sampling indicator light; the sampling completion indicator light and the sampling indicator light are respectively connected to the control module;

[0028] When the electric-controlled pneumatic valve is fully opened and the sampling is confirmed to have officially started, the control module triggers the sampling indicator light;

[0029] When the electric-controlled pneumatic valve is completely closed and the sampling is determined to be finished, the control module triggers the sampling completion indicator light.

[0030] Preferably, the PLC controller comprises an electrical module;

[0031] The electrical module includes an AC / DC power conversion module, which is used to convert an input AC power supply with a voltage of 220V and a frequency of 50Hz into a DC power supply with a voltage of 24V to power the first switch, the electric pump, the electric-controlled pneumatic valve, the normally closed limit switch, the control panel, the PLC control chip, the indicator light group, the button group and the signal transmission module.

[0032] Another technical purpose of the present invention is to provide an intelligent tank sampling method, which is implemented based on the above-mentioned intelligent tank sampling system and includes the following steps:

[0033] Step 1: Place the sampling bottle below the sampling port of the electric-controlled pneumatic valve;

[0034] Step 2: Click the Ready button, and the PLC main control chip determines whether the electric-controlled pneumatic valve is reset. When the judgment result shows that the electric-controlled pneumatic valve is not reset, the PLC main control chip controls the electric-controlled pneumatic valve to perform a reset operation until the electric-controlled pneumatic valve is reset; when the judgment result shows that the electric-controlled pneumatic valve is in a reset state, the PLC main control chip issues a first execution instruction;

[0035] Step 3: Under the control of the first execution instruction, the electric pump starts normally and stops after a period of time t1, triggering the ready indicator light and entering step 3; conversely, under the control of the first execution instruction, the electric pump does not start normally, then press the emergency stop button and enter step 7;

[0036] Step 4: The PLC main control chip issues a second execution instruction to control the electric pump to start working and stop the pump after a period of time t2 to complete the replacement of residual oil in the sampling flow path;

[0037] Step 5. After the electric pump stops for a period of time t3, the PLC main control chip issues a third execution instruction; under the control of the third execution instruction, the operation of opening the electric-controlled pneumatic valve is executed, and different operations are triggered according to whether the electric-controlled pneumatic valve fails: when the electric-controlled pneumatic valve is normally opened under the control of the third execution instruction, it indicates that the electric-controlled pneumatic valve performs sampling, the ready indicator light is turned off, the sampling indicator light is turned on, and the timing is started until the duration t4 of the normal opening of the electric-controlled pneumatic valve reaches the preset time t01 and then it automatically closes, and enters step 6; when the electric-controlled pneumatic valve is in the third If the electric-controlled pneumatic valve does not open normally under the control of the execution instruction, and the duration of the electric-controlled pneumatic valve in the abnormal opening state exceeds the preset time t02, it indicates that the electric-controlled pneumatic valve has a fault, triggering the reset button and the fault alarm buzzer, and turning on the fault alarm indicator light; when the electric-controlled pneumatic valve does not open normally under the control of the third execution instruction, and the duration t5 of the non-opening state is within the range of the preset time t02, the timing starts from the normal opening of the electric-controlled pneumatic valve, until the electric-controlled pneumatic valve is automatically closed after the duration t4 of the normal opening reaches the preset time t01, and the process goes to step six;

[0038] Step 6: Turn off the sampling indicator light and turn on the sampling completion indicator light;

[0039] Step 7, the PLC main control chip issues a fourth execution instruction; under the control of the fourth execution instruction, the electric-controlled pneumatic valve performs a reset operation and turns off the ready indicator light.

[0040] Preferably, the number of the electrically-controlled pneumatic valves is N, which are recorded as electrically-controlled pneumatic valve V1 to electrically-controlled pneumatic valve VN;

[0041] In step 1, a sampling bottle is placed under the sampling port of each electric-controlled pneumatic valve;

[0042] In step 5, when all the electric-controlled pneumatic valves are opened normally, the ready indicator light is turned off and the sampling indicator light is turned on;

[0043] In step 5, when the duration of normal opening of all the electric-controlled pneumatic valves reaches the preset time t0, step 6 is entered;

[0044] In step 5, the duration of normal opening of each electrically-controlled pneumatic valve is equal.

[0045] Based on the above technical objectives, the present invention has the following advantages over the prior art:

[0046] 1. Improve sampling efficiency:

[0047] The present invention can realize intelligent sampling and greatly improve sampling efficiency. For example, a sampler needs to collect samples from 20 storage tanks every day. Manual sampling takes an average of 8 to 10 minutes, while the present invention only takes less than 1 minute to complete the sampling. 140 to 180 minutes of time can be saved every day.

[0048] 2. High authenticity of sample data:

[0049] In manual sampling, since it is a manual operation, the cycle time of the pump often cannot meet the requirement of completely replacing the residual sample; while in automatic sampling, the fixed cycle time of 10 minutes can completely and thoroughly replace the residual medium in the pipeline with the freshest sample, effectively ensuring the authenticity of the collected samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a general diagram of the intelligent tank sampling system of the present invention;

[0051] Figure 2 yes Figure 1 The first part of the electrical schematic diagram of the PLC controller;

[0052] Figure 3 yes Figure 1 The second part of the electrical schematic diagram of the PLC controller;

[0053] Figure 4 yes Figure 1 The third part of the electrical schematic diagram of the PLC controller;

[0054] Figure 5 yes Figure 1 The fourth part of the electrical schematic diagram of the PLC controller;

[0055] Figure 6 yes Figure 1 The fifth part of the electrical schematic diagram of the PLC controller;

[0056] Figure 7 yes Figure 1 Electrical single-line diagram of the PLC controller. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means any limitation to the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise specified, the relative arrangement, expressions and numerical values ​​of the components and steps described in these embodiments do not limit the scope of the present invention. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but in appropriate cases, the techniques, methods and equipment should be regarded as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0058] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations).

[0059] The basic idea of ​​the present invention is to use a PLC controller to uniformly control the electric-controlled pneumatic valve and the electric pump. The sampling personnel sets a fixed sampling time every day (for example, 9 a.m.) on the operation panel (a touch screen can be used), connects the sampling bottle, and presses the ready button on the operation panel, and the system will enter the sampling state. It starts at the set time (9 a.m.), turns on the electric pump to circulate and replace the sampling flow path, and after circulating for about 10 minutes, turns off the electric pump, and opens the electric-controlled pneumatic valve to collect samples. The sampling time (that is, the duration of the normal opening of the electric-controlled pneumatic valve) is the set time (for example, 5 seconds), and the electric-controlled pneumatic valve automatically closes after opening for 5 seconds, and the sampling ends. The sampling personnel go directly to the site to collect the sampling bottles that have collected the samples, reconnect the sampling bottles, and press the ready button, and the system enters the next sampling cycle.

[0060] Because the medium in the storage tank will precipitate and stratify, in order to ensure that the collected samples are representative, the current petrochemical storage tank sampling usually collects samples from 3 to 5 liquid levels in the storage tank at the same time according to the actual situation. Figure 1 The principle is explained by taking three collection points as an example. According to the actual needs of users, the collection points can be increased or decreased on the basis of the present invention.

[0061] like Figure 1 As shown, the intelligent storage tank sampling system described in the present invention includes a PLC controller, a sampling valve (the sampling valve adopted in the present invention is an electro-pneumatic valve, which is provided with two normally open limit switches, corresponding to the first and second limit switches; the electro-pneumatic valve is a straight-through ball valve, having two fluid interfaces, one of which is an injection port, and the other is a sampling port. A pneumatic actuator and an electromagnetic mechanism are provided on the valve body of the electro-pneumatic valve), an electric pump, a sampling bottle, a sampling flow path, and a sample recovery flow path.

[0062] In the electrically controlled pneumatic valve described in the present invention, the valve core is provided with two action positions, one is the open position and the other is the closed position; a pneumatic actuator and an electromagnetic mechanism are provided on the valve body, and the pneumatic actuator is connected to compressed gas; after the electromagnetic mechanism is powered on, the pneumatic actuator rotates the valve core under the action of the compressed gas, and the valve opens; when the electromagnetic mechanism is disconnected from the power supply, the pneumatic actuator returns to its original position and the valve closes; two limit switches are provided on the pneumatic valve, and when the valve core is completely in the open position, the corresponding limit switch is closed; when the valve core is completely in the closed position, the corresponding limit switch is closed; when the valve core is in an intermediate state between not fully open and not fully closed, the two limit switches are both in a disconnected state; the limit switches are provided so that the system can judge the current state of the valve core of the pneumatic valve.

[0063] One end of the sampling flow path is the injection end, and the other end is the sample outlet end; one end of the sample recovery flow path is the injection end, and the other end is the sample outlet end; the injection end of the sampling flow path is connected to a preset sampling point in the storage tank, and the sample outlet end of the sample recovery flow path is connected to the storage tank. The sample outlet end of the sampling flow path is connected to the injection end of the sample recovery flow path and is connected to the injection port of the electric-controlled pneumatic valve after merging. The sampling bottle is arranged below the sampling port of the electric-controlled pneumatic valve.

[0064] The intelligent tank sampling system described in the attached figure can collect samples from three different sampling points at the same time. Therefore, there are three sampling flow paths and three electro-pneumatic valves. One sampling flow path and one electro-pneumatic valve are respectively provided for each sampling point. That is, when there are five sampling points, five sampling flow paths and five electro-pneumatic valves are required. There is only one sample recovery flow path, but the sample recovery flow path is provided with three injection ends, which are connected to the injection port of the electro-pneumatic valve after converging with the sample outlet end of the corresponding sampling flow path. A sampling bottle is arranged under the sampling port of each electro-pneumatic valve.

[0065] An electric pump is installed on the sample recovery flow path, and a one-way valve is arranged between the electric pump and the injection end of the sample recovery flow path. The purpose of arranging the one-way valve is to ensure that the fluid in the sample recovery flow path can only flow in one direction.

[0066] There are two limit switches on the electric-controlled pneumatic valve, one of which is used to limit the open limit position of the valve core, recorded as the first limit switch; the other limit switch is used to limit the closed limit position of the valve core, recorded as the second limit switch. When the valve core of the electric-controlled pneumatic valve is completely in the open position, the first limit switch is closed; when the valve core is completely in the closed position, the second limit switch is closed; when the valve core is in the intermediate state between not fully open and not fully closed, both limit switches are in the disconnected state; the limit switches are set so that the system can determine the current state of the pneumatic valve core.

[0067] The electric-controlled pneumatic valve, the electric pump, and the limit switch are all electrically connected to the PLC controller through wires, and the first switch is connected in series on the wire between the PLC controller and the electric pump. At the same time, the electric-controlled pneumatic valve and the first switch are signal-connected to the PLC controller through a signal transmission line. Electricity is used as the driving power of the electric pump, and the PLC controller controls the operation / stop of the electric pump by controlling the opening and closing of the first switch. Specifically, when the first switch is closed under the control of the PLC controller, the electric pump is powered on and starts to run, and when the first switch is opened under the control of the PLC controller, the electric pump is powered off and stops running.

[0068] Under the control of the PLC controller, after the electromagnetic mechanism of the electric-controlled pneumatic valve is powered on, the pneumatic actuator rotates the valve core of the electric-controlled pneumatic valve under the action of compressed gas until the valve core triggers the first limit switch and causes the first limit switch to close, indicating that the valve core of the electric-controlled pneumatic valve is in a fully open position, and the sample at the preset sampling point in the storage tank flows into the sampling bottle through the sampling flow path and the electric-controlled pneumatic valve in turn;

[0069] Under the control of the PLC controller, the electromagnetic mechanism disconnects the power supply, and the pneumatic actuator drives the valve core to perform the reset operation until the valve core triggers the second limit switch and causes the second limit switch to close, indicating that the valve core of the electric-controlled pneumatic valve is in a fully closed position, cutting off the sample outlet of the sampling flow path;

[0070] The first switch, under the control of the PLC controller, cuts off the power supply to the electric pump and stops the electric pump;

[0071] Under the control of the PLC controller, the first switch turns on the power supply of the electric pump, the electric pump runs, and the samples at the preset sampling points in the storage tank are returned to the storage tank through the sampling flow path and the sample recovery flow path in sequence, thereby realizing the replacement and update of the samples in the sampling flow path.

[0072] Specifically, Figure 2-6 As shown, the PLC controller described in the present invention includes an electrical module and a PLC main control chip, and the PLC main control chip includes a control module, a control panel and an alarm component.

[0073] The electrical module includes an AC / DC power conversion module, which is used to convert an input AC power supply with a voltage of 220V and a frequency of 50Hz into a DC power supply with a voltage of 24V to power the first switch, the electric pump, the electric-controlled pneumatic valve, the travel switch, the touch screen, the PLC control chip, the warning component, the button group and the signal transmission module.

[0074] The warning component includes an indicator light group and a fault alarm buzzer, and the indicator light component includes a fault alarm indicator light (red), a ready indicator light (yellow), a sampling completion indicator light (green) and a sampling indicator light (yellow).

[0075] A button group is arranged on the control panel, and the button group includes a ready button, a reset button, a mute button and an emergency stop button.

[0076] The control module determines whether to control the electric-controlled pneumatic valve and electric pump to reset according to the state of the reset button. When the control module determines that the electric-controlled pneumatic valve has a fault, it triggers the fault alarm indicator and the fault alarm buzzer. The control module determines whether to control the fault alarm buzzer to stop sounding according to the state of the mute button. The control module determines whether to stop sampling, whether to control the electric-controlled pneumatic valve to perform a reset operation, and whether to extinguish the ready indicator according to the state of the emergency stop button. The control module triggers the sampling indicator when the electric-controlled pneumatic valve is fully opened and the sampling is officially started; the control module triggers the sampling completion indicator when the electric-controlled pneumatic valve is fully closed and the sampling is completed.

[0077] The control logic of the present invention is:

[0078] The intelligent tank sampling system has two modes: manual and automatic. The manual mode can control the electric pump and each electric-controlled pneumatic valve on the MIMIC diagram.

[0079] Before all functions start, the electric pneumatic valve is in the closed state.

[0080] Reset status of the intelligent tank sampling system: the electric-controlled pneumatic valve V1, the electric-controlled pneumatic valve V2, the electric-controlled pneumatic valve V3, and the electric pump P1 are closed. The status of each electric-controlled pneumatic valve can be monitored, and the electric pump needs to be observed with the naked eye.

[0081] For the ready button and the reset button, you need to set up soft buttons on the control panel at the same time as setting up the mechanical buttons.

[0082] When a fault occurs in the intelligent tank sampling system, the fault alarm indicator light will light up, the fault alarm buzzer will sound an alarm, and the fault name will be displayed on the control panel.

[0083] After pressing the emergency stop button, sampling stops and the electric-controlled pneumatic valve is reset.

[0084] After pressing the mute button, the fault alarm buzzer stops sounding.

[0085] After pressing the reset button, the electronically controlled pneumatic valve is reset.

[0086] The intelligent tank sampling system will enter the lock screen interface after 5 minutes of inactivity; you will need to enter a password to re-enter the interface. The initial password can be modified.

[0087] The intelligent tank sampling system can be remotely controlled wirelessly, and all status and controls of the intelligent tank sampling system can be displayed on the screen of the remote system.

[0088] Fixed sampling times can be set on the control panel.

[0089] Sampling process:

[0090] Step 1: Place the sampling bottle under the sampling port;

[0091] In this step, since there are N electrically controlled pneumatic valves, which are recorded as electrically controlled pneumatic valves V1 to electrically controlled pneumatic valves VN, a sampling bottle needs to be placed under the sampling port of each electrically controlled pneumatic valve;

[0092] Step 2. Click the Ready button, and the PLC main control chip determines whether the electric-controlled pneumatic valve is reset. When the judgment result shows that the electric-controlled pneumatic valve is not reset, the PLC main control chip controls the electric-controlled pneumatic valve and the electric pump to perform a reset operation until the electric-controlled pneumatic valve and the electric pump are reset (in the initial state, the electric-controlled pneumatic valve and the electric pump are both in a closed state, and reset means returning to the initial state); when the judgment result shows that the electric-controlled pneumatic valve is in a reset state, the PLC main control chip issues a first execution instruction;

[0093] Step 3: Under the control of the first execution instruction, the electric pump starts normally and stops after a period of time t1 (for example, it can be preset to 1 minute), triggering the ready indicator light, and entering step 3; on the contrary, under the control of the first execution instruction, the electric pump does not start normally, then press the emergency stop button (which can be manually operated) and enter step 7;

[0094] Step 4: The PLC main control chip issues a second execution instruction to control the electric pump to start working, and then stops the pump after a period of time t2 (which can be preset to 10 minutes) to complete the replacement of residual oil in the sampling flow path;

[0095] Step 5. After the electric pump stops for a period of time t3 (which can be set to 1s), the PLC main control chip issues a third execution instruction; under the control of the third execution instruction, the operation of opening the electric-controlled pneumatic valve is executed, and different operations are triggered according to whether the electric-controlled pneumatic valve fails: when the electric-controlled pneumatic valve is opened normally under the control of the third execution instruction, it indicates that the electric-controlled pneumatic valve performs sampling, turns off the ready indicator light, turns on the sampling indicator light, and starts timing until the duration t4 of the normal opening of the electric-controlled pneumatic valve reaches the preset time t01 (which can be set to 10s) and then automatically closes, and enters step 6; when the electric-controlled pneumatic valve is opened normally under the control of the third execution instruction, it indicates that the electric-controlled pneumatic valve performs sampling, turns off the ready indicator light, turns on the sampling indicator light, and starts timing until the electric-controlled pneumatic valve is opened normally and automatically closes after reaching the preset time t01 (which can be set to 10s), and enters step 6; when the electric-controlled pneumatic valve is opened normally, it turns off the ready indicator light, turns on the sampling indicator light, and starts timing. The pneumatic valve does not open normally under the control of the third execution instruction, and the duration of the non-normal opening state of the electric-controlled pneumatic valve exceeds the preset time t02 (which can be set to 5s), indicating that the electric-controlled pneumatic valve has a fault, triggering the reset button and the fault alarm buzzer, and turning on the fault alarm indicator light; when the electric-controlled pneumatic valve does not open normally under the control of the third execution instruction, and the duration t5 of the non-opening state is within the range of the preset time t02, the timing starts from the normal opening of the electric-controlled pneumatic valve, until the normal opening duration t4 of the electric-controlled pneumatic valve reaches the preset time t01 and then it automatically closes, and enters step six;

[0096] In this step, it is particularly important to note that, given that there are N electrically-controlled pneumatic valves, the ready indicator light is turned off and the sampling indicator light is turned on only after all electrically-controlled pneumatic valves are opened normally; step six is ​​entered only after the duration of normal opening of all electrically-controlled pneumatic valves reaches the preset time t01; that is, the duration of normal opening of each electrically-controlled pneumatic valve is equal.

[0097] Step 6. Turn off the sampling indicator light and turn on the sampling completed indicator light.

[0098] Step 7. After pressing the emergency stop button, the PLC main control chip issues the fourth execution instruction; under the control of the fourth execution instruction, the electric-controlled pneumatic valve performs a reset operation, turns off the ready indicator light, and sends this information through the remote monitoring system.

Claims

1. An intelligent tank sampling system, comprising a sampling valve, an electric pump, a sampling bottle, a sampling flow path and a sample recovery flow path, characterized in that: It also includes a PLC controller; the sampling valve is an electrically controlled pneumatic valve, and the electrically controlled pneumatic valve is provided with two normally open limit switches, corresponding to the first and second limit switches; wherein: The electric-controlled pneumatic valve is a straight-through ball valve having two fluid interfaces, one of which is an injection port and the other is a sampling port; a pneumatic actuator and an electromagnetic mechanism are arranged on the valve body of the electric-controlled pneumatic valve; One end of the sampling flow path is the injection end, and the other end is the sample outlet end; one end of the sample recovery flow path is the injection end, and the other end is the sample outlet end; The sampling end of the sampling flow path is connected to a preset sampling point in the storage tank, the sampling end of the sample recovery flow path is connected to the storage tank, the sampling end of the sampling flow path is connected to the sampling port of the electric-controlled pneumatic valve after the confluence of the sampling end of the sample recovery flow path, and the sampling bottle is arranged below the sampling port of the electric-controlled pneumatic valve; An electric pump is installed on the sample recovery flow path, and a one-way valve is arranged between the electric pump and the injection end of the sample recovery flow path; the electric-controlled pneumatic valve, the electric pump, and the limit switch are all electrically connected to the PLC controller through wires, and the first switch is connected in series on the wire between the PLC controller and the electric pump, and the electric-controlled pneumatic valve and the first switch are both connected to the PLC controller signal through a signal transmission line; Under the control of the PLC controller, after the electromagnetic mechanism of the electric-controlled pneumatic valve is powered on, the pneumatic actuator rotates the valve core of the electric-controlled pneumatic valve under the action of compressed gas until the valve core triggers the first limit switch and causes the first limit switch to close, indicating that the valve core of the electric-controlled pneumatic valve is in a fully open position, and the sample at the preset sampling point in the storage tank flows into the sampling bottle through the sampling flow path and the electric-controlled pneumatic valve in turn; Under the control of the PLC controller, the electromagnetic mechanism disconnects the power supply, and the pneumatic actuator drives the valve core to perform the reset operation until the valve core triggers the second limit switch and causes the second limit switch to close, indicating that the valve core of the electric-controlled pneumatic valve is in a fully closed position, cutting off the sample outlet of the sampling flow path; The first switch, under the control of the PLC controller, cuts off the power supply to the electric pump and stops the electric pump; Under the control of the PLC controller, the first switch turns on the power supply of the electric pump, the electric pump runs, and the samples at the preset sampling points in the storage tank are returned to the storage tank through the sampling flow path and the sample recovery flow path in sequence, thereby realizing the replacement and update of the samples in the sampling flow path.

2. The intelligent tank sampling system according to claim 1 is characterized in that: The PLC controller includes a PLC main control chip, and the PLC main control chip includes a control module, a control panel and an indicator light group; The control panel is provided with a button group, the button group includes a ready button; the indicator light group includes a ready indicator light; The control module controls the on / off of the ready indicator light according to the state of the ready button.

3. The intelligent tank sampling system according to claim 2 is characterized in that: The button group includes a reset button; The control module determines whether to control the electric-controlled pneumatic valve and the electric pump to reset according to the state of the reset button.

4. The intelligent tank sampling system according to claim 2 or 3, characterized in that: The PLC main control chip is provided with a fault warning device, and the fault warning device includes a fault alarm indicator light and a fault alarm buzzer; When the control module determines that the electric-controlled pneumatic valve has a fault, it triggers a fault alarm indicator light and a fault alarm buzzer.

5. The intelligent tank sampling system according to claim 4 is characterized in that: The button group includes a mute button; The mute button is connected to the control module; The control module determines whether to control the fault alarm buzzer to stop sounding according to the state of the mute button.

6. The intelligent tank sampling system according to claim 2, characterized in that: The button group includes an emergency stop button, The emergency stop button is connected to the control module; The control module determines whether to stop sampling, whether to control the electric-controlled pneumatic valve to perform a reset operation, and whether to extinguish the ready indicator light according to the state of the emergency stop button.

7. The intelligent tank sampling system according to claim 2, characterized in that: The indicator light group includes a sampling completion indicator light and a sampling indicator light; the sampling completion indicator light and the sampling indicator light are respectively connected to the control module; When the electric-controlled pneumatic valve is fully opened and the sampling is confirmed to have officially started, the control module triggers the sampling indicator light; When the electric-controlled pneumatic valve is completely closed and the sampling is determined to be finished, the control module triggers the sampling completion indicator light.

8. The intelligent tank sampling system according to claim 2, characterized in that: The PLC controller includes an electrical module; The electrical module includes an AC / DC power conversion module, which is used to convert an input AC power supply with a voltage of 220V and a frequency of 50Hz into a DC power supply with a voltage of 24V to power the first switch, the electric pump, the electric-controlled pneumatic valve, the normally closed limit switch, the control panel, the PLC control chip, the indicator light group, the button group and the signal transmission module.

9. An intelligent tank sampling method, implemented based on the intelligent tank sampling system according to claim 1, characterized in that: The steps include: Step 1: Place the sampling bottle below the sampling port of the electric-controlled pneumatic valve; Step 2: Click the Ready button, and the PLC main control chip determines whether the electric-controlled pneumatic valve is reset. When the judgment result shows that the electric-controlled pneumatic valve is not reset, the PLC main control chip controls the electric-controlled pneumatic valve to perform a reset operation until the electric-controlled pneumatic valve is reset; when the judgment result shows that the electric-controlled pneumatic valve is in a reset state, the PLC main control chip issues a first execution instruction; Step 3: Under the control of the first execution instruction, the electric pump starts normally and stops after a period of time t1, triggering the ready indicator light and entering step 3; conversely, under the control of the first execution instruction, the electric pump does not start normally, then press the emergency stop button and enter step 7; Step 4: The PLC main control chip issues a second execution instruction to control the electric pump to start working and stop the pump after a period of time t2 to complete the replacement of residual oil in the sampling flow path; Step 5. After the electric pump stops for a period of time t3, the PLC main control chip issues a third execution instruction; under the control of the third execution instruction, the operation of opening the electric-controlled pneumatic valve is executed, and different operations are triggered according to whether the electric-controlled pneumatic valve fails: when the electric-controlled pneumatic valve is normally opened under the control of the third execution instruction, it indicates that the electric-controlled pneumatic valve performs sampling, the ready indicator light is turned off, the sampling indicator light is turned on, and the timing is started until the duration t4 of the normal opening of the electric-controlled pneumatic valve reaches the preset time t01 and then it automatically closes, and enters step 6; when the electric-controlled pneumatic valve is in the third If the electric-controlled pneumatic valve does not open normally under the control of the execution instruction, and the duration of the electric-controlled pneumatic valve in the abnormal opening state exceeds the preset time t02, it indicates that the electric-controlled pneumatic valve has a fault, triggering the reset button and the fault alarm buzzer, and turning on the fault alarm indicator light; when the electric-controlled pneumatic valve does not open normally under the control of the third execution instruction, and the duration t5 of the non-opening state is within the range of the preset time t02, the timing starts from the normal opening of the electric-controlled pneumatic valve, until the electric-controlled pneumatic valve is automatically closed after the duration t4 of the normal opening reaches the preset time t01, and the process goes to step six; Step 6: Turn off the sampling indicator light and turn on the sampling completion indicator light; Step 7, the PLC main control chip issues a fourth execution instruction; under the control of the fourth execution instruction, the electric-controlled pneumatic valve performs a reset operation and turns off the ready indicator light.

10. The intelligent tank sampling method according to claim 9, characterized in that: The number of the electrically-controlled pneumatic valves is N, which are recorded as electrically-controlled pneumatic valve V1 to electrically-controlled pneumatic valve VN; In step 1, a sampling bottle is placed under the sampling port of each electric-controlled pneumatic valve; In step 5, when all the electric-controlled pneumatic valves are opened normally, the ready indicator light is turned off and the sampling indicator light is turned on; In step 5, when the duration of normal opening of all the electric-controlled pneumatic valves reaches the preset time t0, step 6 is entered; In step 5, the duration of normal opening of each electrically-controlled pneumatic valve is equal.

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