Intelligent sampling system and method for soda sampling rack

Abstract

The invention discloses an intelligent sampling system and method for a soda sampling rack. A water sample input pipeline is divided into two paths after passing through a constant temperature and constant pressure device, wherein one path is connected to an online chemical instrument, and the other path is connected to a first opening of a first three-way solenoid valve in a corresponding sampling unit, the second opening of the first three-way solenoid valve is connected to an inlet of an injection valve, the third opening of the first three-way solenoid valve is connected to a water inlet of a manual sampling rack, the outlet of the injection valve is connected to a first opening of a second three-way solenoid valve, the second opening of the second three-way solenoid valve is connected to a water flow monitoring device, the third opening of the second three-way solenoid valve is connected to an inlet of a sampling bottle, the outlet of the sampling bottle is connected to an inlet of a drain valve, and the outlet of the drain valve is connected to a water flow monitoring device. The system and method can avoid various problems caused by a manual sampling method.

Description

Technical Field

[0001] The invention belongs to the field of centralized sampling of steam-water sampling racks in power plants, and relates to an intelligent sampling system and method for steam-water sampling racks. Background Art

[0002] Accurate monitoring of water vapor quality is one of the necessary means to ensure safe and economical operation of power generation units. Correctly collecting representative samples and processing them into water samples at normal temperature and pressure are the prerequisites for accurate monitoring of water vapor quality. For this purpose, thermal power units are generally equipped with centralized steam-water sampling and analysis devices, which mainly consist of high-temperature and high-pressure racks, constant-temperature instrument racks and cooling systems. In order to ensure the accuracy of sampling and testing, each water sample is generally designed to be discharged continuously.

[0003] During the operation of the unit, the water vapor quality is monitored by online chemical instruments and laboratory sampling manual analysis. Laboratory sampling manual analysis is the daily work of power plant personnel. The laboratory personnel will regularly go to the steam sampling rack to manually sample on site, and then take it back to the laboratory for testing and analysis. There are the following problems:

[0004] 1) On-site manual sampling is troublesome. The steam and water sampling points generally include the condensate pump outlet, deaerator inlet, deaerator outlet, economizer inlet, drum boiler water, saturated steam, superheated steam, reheated steam, high-pressure water heater drain, low-pressure water heater drain, closed cooling water, polishing outlet, etc. There are many water samples, and sampling needs to be carried out in sequence, which is labor-intensive and time-consuming;

[0005] 2) The real-time performance of on-site manual sampling is poor. When the water quality fluctuates abnormally, there is a certain lag in sampling on site, and sometimes it is impossible to obtain a typical water sample;

[0006] 2) On-site manual sampling will bring new errors. During the sampling process, water samples will inevitably come into contact with air. The air contains carbon dioxide, which will dissolve and cause deviations in indicators such as pH and conductivity. The longer the exposure to air, the greater the impact. Ultimately, there will be a certain error between the laboratory analysis results and the true value, which will affect the accurate judgment of power plant personnel and have an adverse impact on chemical supervision and control.

[0007] In summary, the current manual sampling method of the soda sampling rack has great limitations, and there is currently no intelligent sampling system and method for the soda sampling rack that is suitable for on-site use, has high accuracy and reliability, and does not require manual intervention. This problem needs to be solved urgently. Summary of the invention

[0008] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a soda sampling rack intelligent sampling system and method, which can avoid various problems caused by manual sampling.

[0009] To achieve the above-mentioned object, the intelligent sampling system of the soda sampling rack of the present invention comprises a constant temperature and constant pressure device, a manual sampling rack, a control system, a DCS system, a plurality of water sample input pipes and a plurality of pairs of sampling units, wherein one water sample input pipe corresponds to a pair of sampling units, wherein the two sampling units in each pair of sampling units each comprise a first three-way solenoid valve, a sampling valve, a second three-way solenoid valve, a sampling bottle, a drain valve and a water flow monitoring device;

[0010] The water sample input pipeline is divided into two paths after passing through the constant temperature and constant pressure device, wherein one path is connected to the online chemical instrument, and the other path is connected to the first opening of the first three-way solenoid valve in the corresponding sampling unit, the second opening of the first three-way solenoid valve is connected to the inlet of the injection valve, the third opening of the first three-way solenoid valve is connected to the water inlet of the manual sampling rack, the outlet of the injection valve is connected to the first opening of the second three-way solenoid valve, the second opening of the second three-way solenoid valve is connected to the water flow monitoring device, the third opening of the second three-way solenoid valve is connected to the inlet of the sampling bottle, the outlet of the sampling bottle is connected to the inlet of the drain valve, and the outlet of the drain valve is connected to the water flow monitoring device;

[0011] The DCS system and the water flow monitoring device are connected to the input end of the control system, and the output end of the control system is connected to the control ends of the first three-way solenoid valve, the second three-way solenoid valve, the injection valve and the drain valve.

[0012] The sampling bottle adopts a bottom-in-top-out flow method.

[0013] The device also comprises a sampling port, which is arranged at the top opening of the sampling bottle.

[0014] The sampling port is provided with a magnetic or threaded groove, and the sampling bottle is connected to the sampling port through the magnetic or threaded groove.

[0015] The two sampling units in each pair of sampling units adopt a one-for-standby and one-for-use working mode.

[0016] The method for intelligent sampling of the soda sampling rack of the present invention comprises the following steps:

[0017] The control system controls the connection between the first opening and the second opening of the first three-way solenoid valve, and disconnects the connection between the first opening and the third opening of the first three-way solenoid valve. The water sample enters the manual sampling rack through the first three-way solenoid valve. The control system opens the injection valve of the bottle to be sampled, controls the connection between the first opening and the second opening of the second three-way solenoid valve, and disconnects the connection between the first opening and the third opening. The water sample passes through the second three-way solenoid valve and is discharged after passing through the water flow monitoring device.

[0018] After the pipeline is flushed clean, the control system controls the connection between the first opening and the third opening of the second three-way solenoid valve, and disconnects the connection between the first opening and the second opening of the second three-way solenoid valve, opens the drain valve, and the water sample enters from the bottom of the sampling bottle. When the sampling bottle is full, the excess water sample enters the water flow monitoring device from the top of the sampling bottle through the drain valve and is discharged. When the water flow monitoring device detects a stable water sample, the control system controls the disconnection between the first opening and the third opening of the second three-way solenoid valve, closes the drain valve, and the sampling is completed.

[0019] The present invention has the following beneficial effects:

[0020] During specific operation, the intelligent sampling system and method of the soda sampling rack described in the present invention utilizes the first three-way solenoid valve to realize the switching of the water sample to the sampling unit and the manual sampling rack, and utilizes the switching of the second three-way solenoid valve to realize the pipeline flushing and sampling process, effectively avoiding direct contact between the water sample and the air, and solving the problems and disadvantages of existing manual sampling. Each water sample has two sets of sampling units, and one is used and the other is reserved under normal circumstances, so as to realize efficient and accurate sampling of each water sampling point in daily life and under abnormal water quality conditions. It is more suitable for on-site use, does not require manual intervention, has the advantages of automation and intelligence, can greatly reduce the workload of power plant personnel, and improve work efficiency, and provides a new method and new idea for the construction of the intelligent sampling system of the soda sampling rack in smart power stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the present invention.

[0022] Among them, 1 is a constant temperature and pressure device, 2 is a manual sampling rack, 3 is the first three-way solenoid valve, 4 is a control system, 5 is an injection valve, 6 is a second three-way solenoid valve, 7 is a sampling bottle, 8 is a sampling port, 9 is a drain valve, 10 is a water flow monitoring device, and 11 is a DCS system. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0024] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0025] refer to Figure 1 The intelligent sampling system and method of the soda sampling rack of the present invention comprises a plurality of water sample input pipes, a constant temperature and pressure device 1, a manual sampling rack 2, a control system 4, a DCS system 11 and a plurality of pairs of sampling units, wherein one water sample input pipe corresponds to a pair of sampling units, wherein the two sampling units in each pair of sampling units each comprise a first three-way solenoid valve 3, a sampling valve 5, a second three-way solenoid valve 6, a sampling bottle 7, a sampling port 8, a drain valve 9 and a water flow monitoring device 10;

[0026] The water sample input pipeline is divided into two paths after passing through the constant temperature and constant pressure device 1, wherein one path is connected to the online chemical instrument, and the other path is connected to the first opening of the first three-way solenoid valve 3 in the corresponding sampling unit, the second opening of the first three-way solenoid valve 3 is connected to the inlet of the injection valve 5, the third opening of the first three-way solenoid valve 3 is connected to the water inlet of the manual sampling rack 2, the outlet of the injection valve 5 is connected to the first opening of the second three-way solenoid valve 6, the second opening of the second three-way solenoid valve 6 is connected to the water flow monitoring device 10, the third opening of the second three-way solenoid valve 6 is connected to the inlet of the sampling bottle 7, the outlet of the sampling bottle 7 is connected to the inlet of the drain valve 9, the outlet of the drain valve 9 is connected to the water flow monitoring device 10, the sampling bottle 7 adopts a bottom-in-top-out flow mode, the sampling port 8 has a magnetic or threaded groove, and the sampling bottle 7 is connected to the sampling port 8 by magnetism or thread.

[0027] The DCS system 11 and the water flow monitoring device 10 are connected to the input end of the control system 4 , and the output end of the control system 4 is connected to the control ends of the first three-way solenoid valve 3 , the second three-way solenoid valve 6 , the injection valve 5 and the drain valve 9 .

[0028] In the non-sampling state, the control system 4 controls the first three-way solenoid valve 3 to be connected between the first opening and the third opening, and to be disconnected between the first opening and the second opening, and the water sample enters the manual sampling rack 2 after passing through the constant temperature and pressure device 1.

[0029] The working process of the present invention is divided into a pipeline cleaning stage and a sampling stage, and the specific process is as follows:

[0030] The control system 4 controls the first opening to the second opening of the first three-way solenoid valve 3 to be connected, and the first opening to the third opening to be disconnected. The water sample enters the manual sampling rack 2 through the first three-way solenoid valve 3. The control system 4 opens the injection valve 5 of the bottle to be sampled 7, controls the first opening to the second opening of the second three-way solenoid valve 6 to be connected, and the first opening to the third opening to be disconnected. The water sample passes through the second three-way solenoid valve 6 and is discharged after passing through the water flow monitoring device 10.

[0031] After the pipeline is flushed, the system enters the sampling stage. The control system 4 controls the connection between the first opening and the third opening of the second three-way solenoid valve 6, and disconnects the connection between the first opening and the second opening. The drain valve 9 is opened, and the water sample enters from the bottom of the sampling bottle 7. When the sampling bottle 7 is full, the excess water sample enters the water flow monitoring device 10 from the top of the sampling bottle 7 through the drain valve 9 and is then discharged. When the water flow monitoring device 10 detects that there is a stable water sample, the control system 4 controls the disconnection between the first opening and the third opening of the second three-way solenoid valve 6, closes the drain valve 9, and the sampling is completed.

[0032] Among them, each type of water sample has two sets of sampling units. Under normal circumstances, one is used and one is reserved, which can meet the automatic sampling needs of daily life and when the water quality fluctuates abnormally. The control system 4 is connected to the output end of the DCS system 11. When an abnormal water sample indicator is detected, the sampling system is activated for automatic sampling.

[0033] The water flow monitoring device 10 monitors the water flow conditions through optical or ultrasonic principles, and transmits the monitoring results to the control system 4 .

[0034] It should be noted that the present invention is more suitable for on-site use, does not require human intervention, has the advantages of automation and intelligence, can greatly reduce the workload of power plant personnel, improve work efficiency, and provides a new method and new idea for the construction of a smart sampling system for a steam-water sampling rack in a smart power station.

Claims

1. A soda sampling rack intelligent sampling system, It is characterized in that The invention comprises a constant temperature and constant pressure device (1), a manual sampling rack (2), a control system (4), a DCS system (11), a plurality of water sample input pipes and a plurality of pairs of sampling units, wherein one water sample input pipe corresponds to a pair of sampling units, wherein the two sampling units in each pair of sampling units each comprise a first three-way solenoid valve (3), a sampling valve (5), a second three-way solenoid valve (6), a sampling bottle (7), a drain valve (9) and a water flow monitoring device (10); The water sample input pipeline is divided into two paths after passing through the constant temperature and constant pressure device (1), wherein one path is connected to the online chemical instrument, and the other path is connected to the first opening of the first three-way electromagnetic valve (3) in the corresponding sampling unit, the second opening of the first three-way electromagnetic valve (3) is connected to the inlet of the injection valve (5), the third opening of the first three-way electromagnetic valve (3) is connected to the water inlet of the manual sampling rack (2), the outlet of the injection valve (5) is connected to the first opening of the second three-way electromagnetic valve (6), the second opening of the second three-way electromagnetic valve (6) is connected to the water flow monitoring device (10), the third opening of the second three-way electromagnetic valve (6) is connected to the inlet of the sampling bottle (7), the outlet of the sampling bottle (7) is connected to the inlet of the drain valve (9), and the outlet of the drain valve (9) is connected to the water flow monitoring device (10); The DCS system (11) and the water flow monitoring device (10) are connected to the input end of the control system (4), and the output end of the control system (4) is connected to the control ends of the first three-way solenoid valve (3), the second three-way solenoid valve (6), the injection valve (5) and the drainage valve (9).

2. The intelligent sampling system for the soda sampling rack according to claim 1, It is characterized in that The sampling bottle (7) adopts a bottom-in-top-out flow mode.

3. The intelligent sampling system for the soda sampling rack according to claim 1, It is characterized in that It also comprises a sampling port (8), which is arranged at the top opening of the sampling bottle (7).

4. The intelligent sampling system for the soda sampling rack according to claim 3, It is characterized in that The sampling port (8) has a magnetic or threaded groove, and the sampling bottle (7) is connected to the sampling port (8) via the magnetic or threaded groove.

5. The intelligent sampling system for the soda sampling rack according to claim 1, It is characterized in that The two sampling units in each pair of sampling units adopt a one-for-standby and one-for-use working mode.

6. A method for intelligent sampling of a soda sampling rack, based on the intelligent sampling system of the soda sampling rack according to claim 5, The following steps are involved: The control system (4) controls the connection between the first opening and the second opening of the first three-way solenoid valve (3), and disconnects the connection between the first opening and the third opening of the first three-way solenoid valve (3), and the water sample enters the manual sampling rack (2) through the first three-way solenoid valve (3). The control system (4) opens the injection valve (5) of the bottle to be sampled (7), controls the connection between the first opening and the second opening of the second three-way solenoid valve (6), and disconnects the connection between the first opening and the third opening, and the water sample passes through the second three-way solenoid valve (6) and is discharged after passing through the water flow monitoring device (10); After the pipeline is flushed, the control system (4) controls the connection between the first opening and the third opening of the second three-way solenoid valve (6), and disconnects the connection between the first opening and the second opening of the second three-way solenoid valve (6), opens the drain valve (9), and the water sample enters from the bottom of the sampling bottle (7). When the sampling bottle (7) is full, the excess water sample enters the water flow monitoring device (10) from the top of the sampling bottle (7) through the drain valve (9) and is then discharged. When the water flow monitoring device (10) detects that there is a stable water sample, the control system (4) controls the connection between the first opening and the third opening of the second three-way solenoid valve (6), and closes the drain valve (9), and the sampling is completed.

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