Steam and water analyser pre-treatment conditioning device

Abstract

The utility model relates to a sample gas pretreatment technical field, is a kind of steam-water analyzer pretreatment control device, it includes sample gas pipe, primary fast pressure reduction pipeline, heat exchanger, temperature control valve and secondary accurate pressure reduction pipeline.The utility model is reasonable and compact in structure, convenient to use, its through primary fast pressure reduction pipeline, secondary accurate pressure reduction pipeline, flowmeter and the pressure detection device in steam-water analyzer instrument can form two-stage linkage's flow pressure composite regulating system, improve flow pressure regulating response speed, to fast, accurate regulation sampling steam pressure, make the pressure of sampling steam can satisfy set pressure requirement, avoid the component distortion caused by pressure fluctuation;Through temperature control valve, spiral pipe heat exchanger and two-stage linkage's flow pressure composite regulating system, establish the collaborative control mechanism of cooling, pressure reduction discharge and flow limiting protection, avoid steam-water analyzer instrument damage caused by sampling steam overtemperature overpressure.

Description

Technical Field

[0001] This utility model relates to the field of steam pretreatment technology and is a pretreatment control device for a steam-water analyzer. Background Technology

[0002] Steam-water analyzers are specialized instruments used in the power industry to detect steam and water quality, primarily applied in the steam-water circulation systems of thermal power plants. These devices utilize online monitoring technology to continuously analyze key parameters in water samples, such as conductivity, pH, dissolved oxygen, and sodium ions, ensuring that the water chemistry of thermal equipment meets standard requirements. The operational data provides crucial information for preventing equipment corrosion and scaling, and improving unit operating efficiency. The steam-water analyzer consists of three parts: a sampling unit, a pretreatment device, and an analysis module. The sampling unit maintains a constant water sample temperature through a constant-temperature cooling device. The pretreatment device includes a pressure-reducing and flow-stabilizing valve and a membrane filter. The analysis module integrates automatic cleaning, temperature compensation, and signal conversion functions. Currently, most steam-water analyzers employ single pressure stabilization or passive cooling methods, which are insufficient to meet the stringent requirements of modern industry, such as <0.01MPa micro-pressure difference control and ±1℃ level constant-temperature control.

[0003] Therefore, existing gas and water analyzers have the following shortcomings in practical use: Analysis lag caused by insufficient flow regulation accuracy: The ball valve-needle valve combined flow control system has a 5 to 10-second regulation delay, failing to match the 5-second rapid response required by the process operation, resulting in insufficient system dynamic response; Component distortion caused by temperature / pressure fluctuations during sample transfer: Flash vaporization is prone to occur during high-temperature depressurization, leading to multiphase flow interference and causing flow meter measurement deviations exceeding ±3%; Inflexible flow path switching and lack of safety redundancy under complex operating conditions: Existing systems generally lack a coordinated control mechanism for depressurization discharge and flow limiting protection, posing a risk of damage to the analyzer under extreme conditions of 500℃ / 10 MPa due to over-temperature and over-pressure. Summary of the Invention

[0004] This utility model provides a pretreatment control device for a steam and water analyzer, which overcomes the shortcomings of the prior art. It can effectively solve the problems of analysis lag caused by insufficient flow regulation accuracy in existing steam and water analyzers; component distortion caused by temperature / pressure fluctuations during sample transmission; and inflexible flow path switching under complex working conditions.

[0005] The technical solution of this utility model is achieved through the following measures: a pretreatment control device for a steam-water analyzer, comprising a sample gas tube, a primary rapid pressure reducing pipeline, a heat exchanger, a temperature control valve, and a secondary precise pressure reducing pipeline. The outlet of the sample gas tube is connected to the inlet of the primary rapid pressure reducing pipeline, the outlet of the primary rapid pressure reducing pipeline is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the inlet of the temperature control valve through a first pipeline, the outlet of the temperature control valve is connected to the inlet of the secondary precise pressure reducing pipeline through a second pipeline, and the outlet of the secondary precise pressure reducing pipeline is connected to a sampling tube that can be connected to the sampling port of the steam-water analyzer.

[0006] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution:

[0007] The aforementioned secondary precision pressure reducing pipeline may include a flow restrictor orifice plate and a needle valve. The inlet of the flow restrictor orifice plate is connected to the inlet of the temperature control valve through a pipeline, the outlet of the flow restrictor orifice plate is connected to the inlet of the needle valve through a pipeline, and the outlet of the needle valve is connected to the sampling tube.

[0008] The aforementioned first-level rapid pressure reducing pipeline may include a ball valve and a plug valve. The inlet of the ball valve is connected to the outlet of the sample gas pipe, the outlet of the ball valve is connected to the inlet of the plug valve through a pipeline, and the outlet of the plug valve is connected to the inlet of the heat exchanger through a pipeline.

[0009] A flow stabilizing valve may be installed on the first pipeline mentioned above.

[0010] A flow-stopping check valve may be installed on the aforementioned second pipeline.

[0011] A flow meter can be installed on the sampling tube mentioned above.

[0012] The heat exchanger mentioned above can be a spiral tube heat exchanger.

[0013] This utility model features a reasonable and compact structure, and is easy to use. It forms a two-stage linked flow and pressure composite regulation system through a primary rapid pressure reducing pipeline, a secondary precise pressure reducing pipeline, a flow meter, and a pressure detection device within the steam-water analyzer. This improves the response speed of flow and pressure regulation, enabling rapid and precise adjustment of the sampling steam pressure to meet the set pressure requirements and avoid component distortion due to pressure fluctuations. Through a temperature control valve, a spiral tube heat exchanger, and the two-stage linked flow and pressure composite regulation system, a coordinated control mechanism of cooling, pressure reduction, and flow limiting protection is established to prevent damage to the steam-water analyzer due to excessive temperature or pressure of the sampling steam. The flow-limiting orifice plate reduces both the steam flow rate and pressure, while also minimizing flash vaporization. The flow stabilizing valve, in conjunction with the two-stage linked flow and pressure composite regulation system, ensures that the steam flow into the temperature control valve is controlled within the set flow range, preventing system instability caused by steam flow fluctuations and thus improving the reliability and efficiency of the device. The flow-cutting check valve prevents water vapor in the steam-water analyzer from flowing back due to pressure changes, addressing the issue of 0.01... Under MPa-level pressure differential change conditions, the system ensures accurate sampling and prevents damage to the steam and water analyzer due to sampling failure caused by over-temperature and over-pressure. This enables precise control of the three parameters of the sampled steam: temperature (30±0.5℃), pressure (0.1±0.003 MPa), and flow rate (1.5±0.03 L / min), with the lag time reduced to less than 5 seconds, meeting the real-time requirements of online analyzers. Attached Figure Description

[0014] Appendix Figure 1 These are schematic diagrams of embodiments 1-7 of this utility model.

[0015] The codes in the attached diagram are as follows: 1 is the sample gas tube, 2 is the heat exchanger, 3 is the temperature control valve, 4 is the first pipe, 5 is the second pipe, 6 is the sampling tube, 7 is the flow limiting orifice plate, 8 is the needle valve, 9 is the ball valve, 10 is the plug valve, 11 is the flow stabilizing valve, 12 is the flow cut-off check valve, 13 is the flow meter, and 14 is the steam-water analysis instrument. Detailed Implementation

[0016] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0017] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0018] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0019] Example 1: As shown in the attached document Figure 1 As shown, the pretreatment control device of the gas analyzer includes a sample gas tube 1, a primary rapid pressure reducing pipeline, a heat exchanger 2, a temperature control valve 3, and a secondary precision pressure reducing pipeline. The outlet of the sample gas tube 1 is connected to the inlet of the primary rapid pressure reducing pipeline, and the outlet of the primary rapid pressure reducing pipeline is connected to the inlet of the heat exchanger 2. The outlet of the heat exchanger 2 is connected to the inlet of the temperature control valve 3 through a first pipe 4. The outlet of the temperature control valve 3 is connected to the inlet of the secondary precision pressure reducing pipeline through a second pipe 5. The outlet of the secondary precision pressure reducing pipeline is connected to a sampling tube 6 that can be connected to the sampling port of the gas analyzer 14.

[0020] In the above technical solution, the first-stage rapid pressure reducing pipeline can quickly reduce the pressure of high-temperature steam by rapidly adjusting the flow rate of high-temperature steam in the pipeline, thereby completing the coarse adjustment of the sampling steam pressure and avoiding damage to the steam-water analyzer 14 due to excessive sampling steam pressure. The first-stage rapid pressure reducing pipeline can be implemented based on existing technologies in this field, such as flow regulating valves, flow limiting orifice plates, V-type ball valves, gate valves, plug valves, needle valves, etc., or multiple flow regulating valve groups with different adjustment speeds and accuracies connected in series can be used to shorten the lag time of steam flow regulation to less than 5 seconds.

[0021] Heat exchanger 2 is mainly used to cool high-temperature steam so that the temperature of the sampled steam meets the set requirements and the sampled steam can meet the temperature requirements of the steam-water analyzer 14 for the sampled medium.

[0022] Temperature control valve 3 is used to detect whether the temperature of the sampled steam after heat exchange and cooling meets the temperature requirements of the steam-water analyzer 14 for the sampled medium (i.e., the set temperature requirement), so as to avoid the sampled steam from overheating and damaging the steam-water analyzer 14.

[0023] The secondary precision pressure reducing pipeline is mainly used to further precisely adjust the pressure of the sampling steam so that the pressure of the sampling steam can meet the pressure requirements of the steam-water analyzer 14 for the sampling medium (i.e., the set pressure requirement), and avoid damage to the steam-water analyzer 14 due to overpressure of the sampling steam. The secondary precision pressure reducing pipeline can use multi-stage pressure reducing regulating valves or multi-stage throttling regulating valves to divide the pressure drop of the regulating valves into several stages to reduce the phenomenon of flash vaporization. For example, multiple needle valves with different regulating accuracies can be connected in series. An expansion pipe can also be set at the outlet of the secondary precision pressure reducing pipeline to reduce the occurrence of flash vaporization of the sampling medium.

[0024] The primary rapid pressure reduction pipeline and the secondary precise pressure reduction pipeline, together with the pressure detection device inside the steam-water analyzer 14, can form a two-stage linkage flow and pressure composite regulation system. This system can precisely regulate the pressure of the sampled steam, ensuring that the pressure of the sampled steam meets the set pressure requirements and preventing component distortion due to pressure fluctuations.

[0025] The sampling tube 6 is used to connect the secondary precision pressure reducing pipeline and the steam-water analyzer 14, so that the required sampling steam can flow into the sampling port of the steam-water analyzer 14.

[0026] During operation, the sampled high-temperature steam flows into the primary rapid pressure reduction pipeline through the sample gas pipe 1. After passing through the primary rapid pressure reduction pipeline, the high-temperature steam undergoes initial pressure reduction. The initially depressurized high-temperature steam then passes through the heat exchanger 2 to obtain low-temperature initially depressurized steam. The temperature control valve 3 can detect whether the temperature of the low-temperature initially depressurized steam meets the set temperature requirement. If it does not, the temperature control valve 3 is closed, and the flow rate of the high-temperature steam can be further adjusted (reduced) through the primary rapid pressure reduction pipeline. If conditions permit, the temperature of the cold medium in the heat exchanger 2 can also be reduced to further reduce the temperature of the sampled steam until the temperature of the low-temperature initially depressurized steam meets the set temperature requirement. At this point, the temperature control valve 3 automatically opens, allowing the low-temperature initially depressurized steam to flow into the secondary precision pressure reduction pipeline. The secondary precision pressure reduction pipeline further precisely adjusts the pressure of the low-temperature initially depressurized steam to obtain sampled steam with pressure and temperature that meet the set pressure and set temperature, respectively. The sampled steam flows into the sampling port of the steam-water analyzer 14 through the sampling pipe 6, thereby completing the water vapor quality detection of the sampled steam. If the pressure of the sampled steam detected by the steam-water analyzer 14 does not meet the set pressure requirement, the pressure of the sampled steam can be adjusted through the secondary precision pressure reducing pipeline until the pressure of the sampled steam meets the set pressure requirement.

[0027] This utility model has a reasonable and compact structure and is easy to use. It forms a two-stage linkage flow and pressure composite regulation system through a primary rapid pressure reduction pipeline, a secondary precise pressure reduction pipeline, and a pressure detection device inside the steam and water analyzer 14. This improves the flow and pressure regulation response speed, enabling rapid and precise adjustment of the sampling steam pressure to meet the set pressure requirements and avoid component distortion due to pressure fluctuations. Through the temperature control valve 3 and the two-stage linkage flow and pressure composite regulation system, a coordinated control mechanism of cooling, pressure reduction discharge, and flow limiting protection is established to prevent damage to the steam and water analyzer 14 due to excessive temperature or pressure of the sampling steam.

[0028] The pretreatment control device of the above-mentioned steam and water analyzer can be further optimized and / or improved according to actual needs:

[0029] Example 2: As an optimization of the above examples, as shown in the appendix Figure 1 As shown, the secondary precision pressure reducing pipeline includes a flow limiting orifice plate 7 and a needle valve 8. The inlet of the flow limiting orifice plate 7 is connected to the inlet of the temperature control valve 3 through a pipeline, the outlet of the flow limiting orifice plate 7 is connected to the inlet of the needle valve 8 through a pipeline, and the outlet of the needle valve 8 is connected to the sampling tube 6.

[0030] During operation, as the low-temperature, initially depressurized steam flows through the flow-limiting plate 7, the flow-limiting orifice plate 7 increases the flow rate of the low-temperature, initially depressurized steam through throttling, further reducing the pressure of the low-temperature steam to within the set range. At this time, the needle valve 8 can further precisely adjust the pressure of the low-temperature steam, ensuring that the pressure of the sampling steam is controlled within the set pressure requirement range, thus completing the fine adjustment of the sampling steam pressure and preventing damage to the steam-water analyzer 14 due to overpressure of the sampling steam. In this embodiment, the set pressure requirement can be 0.1 ± 0.003 MPa.

[0031] In addition, the flow-limiting orifice plate 7 can also prevent overload. By limiting the steam flow rate and reducing the steam pressure, it can also reduce the occurrence of flash vaporization.

[0032] Example 3: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, the first-stage rapid pressure reducing pipeline includes a ball valve 9 and a plug valve 10. The inlet of the ball valve 9 is connected to the outlet of the sample gas pipe 1, the outlet of the ball valve 9 is connected to the inlet of the plug valve 10 through a pipeline, and the outlet of the plug valve 10 is connected to the inlet of the heat exchanger 2 through a pipeline.

[0033] During use, ball valve 9 exhibits relatively low fluid resistance in both fully open and fully closed states, making it more suitable for high-temperature and high-pressure environments and enabling rapid control of fluid flow. Meanwhile, plug valve 10, with its unique valve core design, allows for more precise adjustment of the fluid passage diameter, achieving accurate flow regulation. Although the flow regulation accuracy of plug valve 10 is not as high as that of needle valve 8, its flow regulation speed is much faster, reducing the lag time for steam flow regulation to less than 5 seconds, making it ideal for coarse adjustment of high-temperature steam flow.

[0034] In the above technical solution, the plug valve 10 can finely adjust the flow rate of high-temperature steam in the pipeline, reduce the pressure of high-temperature steam in the pipeline, achieve initial pressure reduction of high-temperature steam, greatly reduce the pressure of high-temperature steam sample, and complete the coarse adjustment of high-temperature steam pressure.

[0035] Example 4: As an optimization of the above embodiments, as shown in the appendix. Figure 1 As shown, a flow stabilizing valve 11 is installed on the first pipe 4.

[0036] In the above technical solution, the flow stabilizing valve 11 can stabilize the flow rate of the sampled steam in the first pipeline 4, ensuring that the steam in the first pipeline 4 flows at a constant rate, reducing disturbances, and controlling the steam flow rate into the temperature control valve 3 within the set flow rate range. This avoids system instability caused by steam flow rate fluctuations, thereby improving the reliability and efficiency of the device. In this embodiment, the set flow rate can be 1.5 ± 0.03 L / min.

[0037] During use, the flow regulation response time can be shortened to 2.8 seconds through the dynamic cooperation between the plug valve 10 (which controls three states: fully open, throttling, and fully closed) and the flow regulator 11.

[0038] Example 5: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, the second pipeline 5 is equipped with a flow-stopping check valve 12.

[0039] With this configuration, the flow-stop check valve 12 can not only control the flow of fluid in the second pipeline 5, but also prevent water vapor in the steam-water analyzer 14 from flowing back due to pressure changes. This is to cope with sudden pressure changes of 0.01 MPa, ensure correct sampling, and prevent damage to the steam-water analyzer 14 due to sampling failure caused by overheating and overpressure.

[0040] Example 6: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, a flow meter 13 is installed on the sampling tube 6.

[0041] This setup allows for more intuitive observation of the real-time flow rate of water vapor in sampling tube 6. Since there is a direct proportional relationship between pressure and flow rate in the pipeline, the flow meter 13 can quickly determine whether the pressure of the sampled steam flowing into the sampling port of the steam-water analyzer 14 meets the set pressure requirement. In this embodiment, the set pressure requirement can be 0.1 ± 0.003 MPa.

[0042] Depending on the requirements, the flow meter 13 may be a smart flow meter 13 from the prior art.

[0043] By using the pressure detection device in the temperature control valve 3, flow meter 13, and steam-water analyzer 14, a coordinated control mechanism for pressure reduction and flow restriction protection can be established, effectively reducing the risk of damage to the analyzer due to overheating and overpressure of the sampled steam under extreme conditions of 500℃ / 10 MPa.

[0044] Example 7: As an optimization of the above embodiments, as shown in the appendix Figure 1 As shown, heat exchanger 2 is a spiral tube heat exchanger 2.

[0045] The spiral tube heat exchanger 2 in the above technical solution is a conventional spiral tube heat exchanger 2, which is made of one or more sets of spirally wound tubes placed in a shell. The high-temperature steam in this device is mainly used for steam quality detection, with a relatively small flow rate. The spiral structure of the spiral tube heat exchanger 2 increases the heat exchange contact area and optimizes fluid dynamics, resulting in higher heat exchange efficiency, lower energy consumption, a greater hysteresis heat transfer coefficient than the straight tube heat exchanger 2, a more compact structure, easier installation and maintenance, no thermal stress-induced leakage, self-cleaning function, and low scaling tendency. Therefore, the spiral tube heat exchanger 2 has better heat exchange effect, achieving precise temperature reduction from 500℃ to 25℃ (gradient ≤ 5℃ / s), thus controlling the steam temperature exiting the spiral tube heat exchanger 2 within the set temperature range and avoiding component distortion due to temperature fluctuations. In this embodiment, the set temperature requirement can be 30±0.5℃.

[0046] The above technical features constitute various embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A pretreatment control device for a steam-water analyzer, characterized in that... It includes a sample gas pipe, a primary rapid pressure reducing pipeline, a heat exchanger, a temperature control valve, and a secondary precise pressure reducing pipeline. The outlet of the sample gas pipe is connected to the inlet of the primary rapid pressure reducing pipeline, the outlet of the primary rapid pressure reducing pipeline is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the inlet of the temperature control valve through a first pipeline, the outlet of the temperature control valve is connected to the inlet of the secondary precise pressure reducing pipeline through a second pipeline, and the outlet of the secondary precise pressure reducing pipeline is connected to a sampling pipe that can be connected to the sampling port of a gas-water analysis instrument.

2. The pretreatment control device for a steam-water analyzer according to claim 1, characterized in that, The secondary precision pressure reducing pipeline includes a flow restrictor orifice plate and a needle valve. The inlet of the flow restrictor orifice plate is connected to the inlet of the temperature control valve through a pipeline, the outlet of the flow restrictor orifice plate is connected to the inlet of the needle valve through a pipeline, and the outlet of the needle valve is connected to the sampling tube.

3. The pretreatment control device for a steam-water analyzer according to claim 1 or 2, characterized in that, The primary rapid pressure reducing pipeline includes a ball valve and a plug valve. The inlet of the ball valve is connected to the outlet of the sample gas pipe, the outlet of the ball valve is connected to the inlet of the plug valve through a pipeline, and the outlet of the plug valve is connected to the inlet of the heat exchanger through a pipeline.

4. The pretreatment control device for a steam-water analyzer according to claim 1 or 2, characterized in that, A flow control valve is installed on the first pipeline; Or / and, a flow-stopping check valve is installed on the second pipeline.

5. The pretreatment control device for a steam-water analyzer according to claim 3, characterized in that, A flow control valve is installed on the first pipeline; Or / and, a flow-stopping check valve is installed on the second pipeline.

6. The pretreatment control device for a steam-water analyzer according to claim 1, 2, or 5, characterized in that, A flow meter is installed on the sampling tube.

7. The pretreatment control device for a steam-water analyzer according to claim 3, characterized in that, A flow meter is installed on the sampling tube.

8. The pretreatment control device for a steam-water analyzer according to claim 4, characterized in that, A flow meter is installed on the sampling tube.

9. The pretreatment control device for a steam-water analyzer according to claim 1, 2, 5, 7, or 8, characterized in that, The heat exchanger is a spiral tube heat exchanger.

10. The pretreatment control device for a steam-water analyzer according to claim 6, characterized in that, The heat exchanger is a spiral tube heat exchanger.

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