A draining device and method for protecting chemical instruments during unit startup.

Abstract

This invention belongs to the field of online water quality analysis and pretreatment technology, and discloses a sewage discharge device and method for protecting chemical instruments during unit startup, including a sample inlet tube and a filtration system. The inlet end of the sample inlet tube is connected to the sampling point of the target water vapor system, and the outlet end of the sample inlet tube extends into the interior of the filtration system. The filtration system includes a main system cavity, a conical sludge collection cavity, a filter tube, and several inclined plates. The main system cavity and the conical sludge collection cavity are vertically connected, the outlet end of the sample inlet tube extends to the bottom end of the main system cavity, and the filter tube is horizontally set at the top end of the main system cavity. The outlet end of the filter tube extends to the outside of the main system cavity and is connected to the inlet of the chemical instruments. Several inclined plates are inclinedly set in the lower middle part of the main system cavity. Adjacent inclined plates are spaced apart. This invention, through the cooperation of the filter tube and the inclined plates, can achieve efficient interception and separation of water vapor corrosive particles such as iron oxides, ensuring the safe operation of downstream chemical instruments.

Description

Technical Field

[0001] This invention belongs to the field of online water quality analysis and pretreatment technology, and specifically relates to a sewage discharge device and method for protecting chemical instruments during unit startup. Background Technology

[0002] During long-term shutdowns of thermal power units or the initial commissioning phase of newly built units, water samples commonly exhibit excessive impurities, severely impacting the accuracy of online chemical instrument monitoring. During unit shutdowns, the boiler body and the metal inner walls of steam and water pipelines undergo oxidation with air and steam, continuously generating rust and other oxidation corrosion products. Newly built units often retain solid impurities such as welding slag, metal fragments, and dust during pipeline welding, equipment installation, and pipeline purging. When the unit enters cold or warm-state start-up conditions, the system's water circulation washes away and carries away various impurities accumulated in the pipelines, causing a sharp increase in the concentration of particulate impurities in the sampled water, resulting in a typical "black water" phenomenon. This interferes with normal water and steam quality monitoring and directly threatens the safety of unit start-up, shutdown, and long-term operation.

[0003] To address the issues of high impurity content and poor water quality in sampled water during the start-up phase of a generating unit, the industry currently generally adopts mechanical filtration structures for end-of-sampling pretreatment devices. These devices remove particulate impurities and oxides from the water sample through physical interception. Existing pretreatment devices are mainly divided into two types of filtration structures: cartridge filters and metal mesh filters. They can achieve basic water purification effects under normal operating conditions, but their adaptability and operational reliability decrease significantly in the high-impurity, high-pollution black water conditions during the initial start-up phase of the generating unit.

[0004] Specifically, traditional mechanical filtration structures have limited impurity capacity. During startup, a large amount of impurities quickly clogs the filter elements or metal mesh pores, causing filter element failure and obstructed water flow in the sampling pipeline. Furthermore, existing equipment lacks autonomous drainage capabilities, meaning accumulated impurities cannot be cleared automatically. Maintenance personnel must periodically disassemble, clean, or replace filter elements, increasing on-site maintenance workload and equipment operating costs, and causing frequent interruptions to the continuous operation of the sampling system. In addition, manual inspection and maintenance inherently have a lag; clogged filter elements are difficult to address promptly, leading to delayed water quality monitoring responses, data distortion, and interruptions, resulting in poor operational stability of the sampling system. In summary, existing sampling pretreatment devices cannot adapt to the complex high-impurity conditions during unit startup and shutdown, making it difficult to achieve continuous and stable water sample purification. This presents significant operational risks and fails to meet the water quality monitoring and assurance requirements for the safe operation of thermal power units. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the present invention provides a sewage discharge device and method for protecting chemical instruments during unit startup, in order to solve the technical problem that existing sampling pretreatment devices cannot adapt to the high impurity and complex operating conditions during unit startup and shutdown, and are difficult to achieve continuous and stable water sample purification.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a draining device for protecting chemical instruments during unit startup, comprising a sample inlet tube and a filtration system; the inlet end of the sample inlet tube is used to connect to the sampling point of the target water vapor system, and the outlet end of the sample inlet tube extends into the interior of the filtration system; The filtration system includes a main system chamber, a conical mud collection chamber, filter tubes, and several inclined plates; The main cavity of the system is vertically connected to the conical mud collection cavity. The outlet end of the sample inlet tube extends to the bottom end of the main cavity of the system, and the filter tube is horizontally arranged at the top end of the main cavity of the system. The outlet end of the filter tube extends to the outside of the main cavity of the system and is connected to the inlet of the chemical instrument. Several inclined plates are inclinedly arranged in the lower middle part of the main cavity of the system. Adjacent inclined plates are spaced apart.

[0007] Furthermore, the bottom of the outlet end of the sample inlet tube is provided with a plurality of sample water through holes; the plurality of sample water through holes are evenly distributed along the axis of the sample inlet tube, and the openings of the sample water through holes are arranged facing the side of the conical mud collection chamber.

[0008] Furthermore, the filter tube is a ceramic membrane filter tube or a stainless steel sintered filter tube.

[0009] Furthermore, the filtration accuracy of the filter tube is 5-50μm.

[0010] Furthermore, the angle between the inclined plate and the horizontal plane is 55°-65°.

[0011] Furthermore, an injection valve is provided at the inlet end of the injection tube; the injection valve is used to control the opening and closing of the injection tube and to adjust the flow rate of the sample water in the injection tube.

[0012] Furthermore, the filtration system also includes a drain valve; the drain valve is located at the lowest point of the conical sludge collection chamber and is used to discharge the deposited particulate impurities collected in the conical sludge collection chamber.

[0013] Furthermore, the filtration system also includes a turbidity measuring instrument; the turbidity measuring instrument is installed at the outlet end of the filter tube and is used to measure the turbidity data of the water effluent from the filter tube.

[0014] Furthermore, it also includes a control unit; the input terminal of the control unit is connected to the output terminal of the turbidity measuring instrument, and the output terminal of the control unit is connected to the control terminal of the drain valve; The control unit is used to control the opening and closing of the drain valve according to the turbidity data of the water effluent from the filter tube and a preset drain control strategy.

[0015] The present invention also provides a method for draining chemical instruments during unit startup to protect them, utilizing the aforementioned draining device for protecting chemical instruments during unit startup, the method comprising: The sample water in the target water vapor system is transported to the bottom of the filtration system using the sample inlet tube; after entering the filtration system, the sample water flows from bottom to top; when the sample water flows through the inclined plate and filter tube, the particulate impurities in the sample water are intercepted and separated, so that the clarified sample water enters the chemical instrument through the outlet of the filter tube. The trapped particulate impurities accumulate on the outer surface of the filter tube. When the accumulation thickness of the particulate impurities reaches the target value, they naturally slide down to the inclined plate under the action of gravity, and after shallow settling on the surface of the inclined plate, they continue to slide down and collect in the conical mud collection cavity.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a drainage device for protecting chemical instruments during unit startup. Through the combination of filter tubes and inclined plates, it can efficiently intercept and separate corrosive particles such as iron oxides, ensuring the safe operation of downstream chemical instruments. Specifically, water samples are directly transported to the bottom of the main system cavity via an inlet tube. Utilizing the upward flow path of the water sample, and with the help of several inclined plates arranged in the middle and lower sections forming a multi-stage baffle sedimentation structure, particulate impurities in the water sample are separated and settled step by step under the action of gravity and inertia. The settled particulate impurities collect in the lower conical sludge collection cavity, achieving efficient collection and isolation of particulate impurities. The water sample, decelerated by the inclined plates, flows upward to the top of the main system cavity, where it undergoes terminal filtration through horizontally arranged filter tubes. The filter ultimately provides purified, clear water samples for chemical instruments. In this invention, a two-stage synergistic purification mechanism of inclined plate sedimentation and filter tube interception filtration significantly improves the device's impurity holding capacity and avoids the problem of rapid clogging of a single filter element under high impurity conditions during the start-up phase. At the same time, the sludge collection structure of the conical sludge collection chamber and the interval arrangement of the inclined plates form a continuous autonomous sludge discharge space. After the impurities settle, they naturally collect in the bottom sludge collection chamber, eliminating the need for frequent disassembly, cleaning, or replacement of filter elements. This reduces the frequency of manual maintenance and the risk of system interruption, ensuring the continuous and stable operation of the sampling system during unit start-up and shutdown. Thus, it effectively solves the technical problem that existing pretreatment devices cannot adapt to complex high-impurity conditions and are difficult to achieve continuous and stable water sample purification.

[0017] Furthermore, the bottom of the outlet end of the sample tube is evenly distributed along the axis and opened towards the conical mud collection chamber. This allows the sample water to be evenly distributed through multiple holes, ensuring that the high-pressure, high-impurity sample water is evenly diffused and released. This prevents the settled particulate impurities from being rolled up and disturbed by the water flow and floating up again. At the same time, it can guide large particulate impurities in the sample water to settle directly towards the mud collection area, enhancing the pre-separation effect of impurities in the early stage.

[0018] Furthermore, the filter tubes are made of ceramic membrane or stainless steel sintered tubes, which have the characteristics of high structural strength, erosion resistance, corrosion resistance and uniform and stable pores, effectively extending the service life of filter elements, reducing equipment consumable replacement costs and maintenance frequency, and ensuring the long-term stable operation of the sampling filtration system.

[0019] Furthermore, by limiting the filtration accuracy of the filter tube to 5-50μm, it can adapt to the particle size distribution characteristics of water samples under the start-up conditions of thermal power units, achieving the optimal match between water sample filtration accuracy and water flow stability, while taking into account both purification effect and sampling continuity.

[0020] Furthermore, setting the inclination angle of the inclined plate to the horizontal plane to 55°-65° is the optimal angle range for impurity settling and sliding. This effectively ensures that large particles of impurities in the water sample quickly complete shallow settling on the surface of the inclined plate. At the same time, relying on gravity, the settled impurities slide smoothly down into the conical sludge collection chamber, leaving no impurities residue or accumulation. This maintains the settling and diversion performance of the inclined plate, stably achieves multi-stage impurity pre-separation, and continuously reduces the filtration load on the downstream filter tubes.

[0021] Furthermore, the sampling valve installed at the inlet end of the sampling tube can controllably switch the sampling pipeline on and off and precisely adjust the water sample flow rate, thus achieving adaptability for water sample filtration and sampling monitoring under different operating conditions.

[0022] Furthermore, the drain valve located at the lowest point of the conical mud collection chamber enables the equipment to automatically discharge sewage at designated points, eliminating the need for manual disassembly of the equipment and cleaning of the filter elements to remove impurities.

[0023] Furthermore, the control unit can adaptively adjust the opening degree and duration of the drain valve based on real-time turbidity data and preset drain strategies, thereby achieving precise draining on demand. This effectively improves the automation and intelligence of the equipment and adapts to the complex and ever-changing high-impurity operating conditions during the start-up and shutdown phases of the unit.

[0024] The method for draining chemicals during unit startup provided by this invention has all the advantages of the aforementioned draining device for protecting chemicals during unit startup. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the structure of the draining device for protecting chemical instruments during unit startup provided in Example 1; Figure 2 This is a flowchart of the control unit in Example 1.

[0027] The components include: 1. Inlet tube; 2. Filtration system; 3. Control unit; 11. Inlet valve; 12. Sample water through hole; 21. Main system chamber; 22. Conical mud collection chamber; 23. Filter tube; 24. Inclined plate; 25. Drain valve; 26. Turbidity measuring instrument. Detailed Implementation

[0028] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] Before describing the specific embodiments of this application, some of the technical terms involved in the embodiments of this application are explained as follows: A cartridge-type filtration structure refers to a structure that relies on the physical interception effect of a porous filter cartridge to block impurities such as iron oxides and solid particles in water.

[0030] Metal mesh filter structure refers to the use of high-precision metal woven mesh as the filter medium, which achieves impurity filtration through the sieving effect of the mesh openings.

[0031] To address the problems in the existing technology, the inventors discovered in practical work that during the cold or warm start-up phase of thermal power units, a large amount of oxidation and corrosion products are generated in the boiler body and steam-water pipelines during shutdown. In addition, impurities remaining during the construction of new units result in high concentrations of iron oxides and particulate impurities in the sampled water, often exhibiting a noticeable "black water" phenomenon. Existing pretreatment devices for the sampling end of online chemical instruments mostly adopt filter cartridge or metal mesh filtration structures, which generally suffer from severe clogging, frequent manual replacement, inability to automatically discharge pollutants, and delayed response. Especially in the initial stage of unit startup, the particulate matter content is high, and the filter elements are prone to rapid clogging, leading to unstable operation of the sampling system, which in turn affects the normal monitoring of chemical indicators and poses a hidden danger to the safe operation of the unit.

[0032] Based on this, the present invention provides a sewage discharge device for protecting chemical instruments during unit startup, comprising a sample inlet tube 1 and a filtration system 2; the inlet end of the sample inlet tube 1 is connected to the sampling point of the target water vapor system, and the outlet end of the sample inlet tube 1 extends into the interior of the filtration system 2; the filtration system 2 includes a main system cavity 21, a conical sludge collection cavity 22, a filter tube 23, and several inclined plates 24; the main system cavity 21 and the conical sludge collection cavity 22 are vertically connected, the outlet end of the sample inlet tube 1 extends to the bottom end of the main system cavity 21, and the filter tube 23 is horizontally arranged at the top end of the main system cavity 21; wherein, the outlet end of the filter tube 23 extends to the outside of the main system cavity 21 and is connected to the inlet of the chemical instruments; several inclined plates 24 are inclinedly arranged in the lower middle part of the main system cavity 21; wherein, adjacent inclined plates 21 are spaced apart.

[0033] In the above embodiment, by integrating the main system cavity 21 and the conical sludge collection cavity 22 connected vertically in the filtration system 2, and with the inclined plates 24 spaced at intervals in the lower part of the main system cavity 21 and the filter tubes 23 arranged horizontally at the top, a graded purification structure is formed, which is specifically adapted to the complex working conditions of high impurities and high pollution black water during the start-up phase of the unit. When the unit starts up, the water sample carrying a large amount of rust, welding slag and metal debris is introduced into the bottom of the main system cavity 21 through the sample inlet pipe 1. The large particles of impurities are initially intercepted and settled by the settling and diversion effect of the inclined plates 24. The settled impurities can be collected in the conical sludge collection cavity 22, which greatly reduces the situation where fine impurities directly impact the filter tubes 23. This effectively avoids the problems of limited impurity holding space and easy rapid clogging of filter pores in traditional filtration structures, ensuring that the filter tubes 23 are permeable for a long time and that the sampling pipeline flows smoothly.

[0034] Secondly, the water sample, after being decelerated by the inclined plate 24, flows upward to the top of the main cavity 21 of the system, and undergoes terminal filtration through the horizontally arranged filter tube 23, ultimately providing purified and clarified water sample for the chemical instruments. At the same time, this invention enables the autonomous settling and collection of impurities, eliminating the need for maintenance personnel to frequently disassemble, clean, or replace filter elements, significantly reducing on-site maintenance workload and equipment operating costs. It avoids the problem of sampling system operation interruption caused by manual maintenance, and eliminates problems such as delayed water quality monitoring response and data distortion caused by the lag in manual maintenance. It effectively improves the continuity and stability of water sample purification during the unit start-up and shutdown phases, reliably ensuring the accuracy of water quality monitoring by chemical instruments during the start-up, shutdown, and long-term operation of thermal power units, and meeting the water quality monitoring guarantee requirements for safe unit operation.

[0035] The following detailed explanation, using specific embodiments, further illustrates the draining device provided by the present invention for protecting chemical instruments during unit startup: Example 1 As attached Figure 1 As shown, this embodiment 1 provides a draining device for protecting chemical instruments during unit startup, including a sample inlet pipe 1 and a filtration system 2; the inlet end of the sample inlet pipe 1 is connected to the sampling point of the target water vapor system, the outlet end of the sample inlet pipe 1 extends into the interior of the filtration system 2, and the outlet end of the filtration system 2 is connected to the downstream chemical instrument inlet; wherein, the sample inlet pipe 1 is used to transport sample water from the target water vapor system to the filtration system 2; the filtration system 2 is used to intercept and separate particulate impurities in the sample water, forming clarified sample water, which is then transported to the downstream chemical instruments.

[0036] The inlet end of the sample inlet tube 1 is provided with a sample inlet valve 11, which is an electrically controlled switch valve or a manual ball valve. The sample inlet valve 11 is used to control the opening and closing of the sample inlet tube 1 so that the water inlet of the whole machine can be shut off during device maintenance, fault repair and other working conditions. Optionally, the sample inlet valve 11 can also adjust the sample water flow rate in the sample inlet tube 1. The outlet end of the sample inlet tube 1 extends to the bottom end of the main cavity 21 of the filtration system 2 so as to directly deliver the sample water to the bottom end of the main cavity 21 of the system, thereby making the sample water flow from bottom to top in the filtration system 2.

[0037] The bottom of the outlet end of the sample inlet tube 1 is provided with a plurality of sample water through holes 12, which are evenly distributed along the axis of the sample inlet tube 1. All sample water through holes 12 are located at the bottom of the main cavity 21 of the system, and the openings of the sample water through holes 12 are oriented towards the conical mud collection cavity 22. Specifically, each sample water through hole 12 is oriented downwards. Optionally, the sample water through holes 12 are circular through holes, and the number is 3-5. The diameter of each sample water through hole 12 is set according to the sample water flow rate requirement to avoid disturbing the sedimentation flow field in the conical mud collection cavity 22 of the filtration system 2.

[0038] The filtration system 2 includes a main system cavity 21, a conical sludge collection cavity 22, a filter tube 23, and several inclined plates 24. The main system cavity 21 and the conical sludge collection cavity 22 are vertically connected to form a hollow cavity structure. Specifically, the main system cavity 21 is a hollow shell structure with an open lower end, and the conical sludge collection cavity 22 is a filter bucket structure with an open upper end. The main system cavity 21 is located above the conical sludge collection cavity 22, and the lower end of the main system cavity 21 is connected to the upper end of the conical sludge collection cavity 22.

[0039] The filter tube 23 is horizontally disposed at the top of the main cavity 21 of the system, and the outlet end of the filter tube 23 extends to the outside of the main cavity 21 of the system and is connected to the inlet of the chemical instrument. Optionally, the filter tube 23 is a ceramic membrane filter tube or a stainless steel sintered filter tube, and the filtration accuracy is set according to the application requirements. Preferably, the filtration accuracy of the filter tube 23 is 5-50μm.

[0040] It should be noted that the axis of the filter tube 23 is set relatively horizontally. When the sample water flows through the filter tube 23, particulate impurities are trapped on the outer surface of the filter tube 23. The filtered clear sample water flows into the chemical instrument through the outlet of the filter tube 23. When the thickness of the particulate impurities accumulated on the outer surface of the filter tube 23 reaches the target value, they will naturally slide down to the area of ​​the inclined plate 24 below under the action of gravity, effectively avoiding the clogging problem of traditional dead-end filters.

[0041] Several inclined plates 24 are inclinedly disposed in the lower middle part of the main cavity 21 of the system; wherein, adjacent inclined plates 24 are spaced apart; preferably, the inclination angle between the inclined plate 24 and the horizontal plane is 55°-65°, and the length of the inclined plate 24 is 40-80mm; specifically, the inclined plate 24 includes an upper straight plate section, a middle inclined plate section and a lower straight plate section connected from top to bottom, the upper straight plate section is vertically disposed in the middle of the main cavity 21 of the system, and the lower straight plate section is vertically disposed at the lower end of the main cavity 21 of the system; the upper straight plate section and the lower straight plate section are located on different vertical planes, and the middle inclined plate section is inclinedly disposed between the upper straight plate section and the lower straight plate section.

[0042] It should also be noted that the inclined plate 24 is set in the lower middle part of the main cavity 21 of the system and above the outlet end of the sample inlet tube 1. When the unit is started, the water sample carrying a large amount of rust, welding slag and metal debris is introduced into the bottom end of the main cavity 21 of the system through the sample inlet tube 1. The large particles of impurities are initially intercepted and settled by the settling and diversion effect of the inclined plate 24. The settled impurities can be collected in the conical mud collection chamber 22, which greatly reduces the situation where fine impurities directly impact the filter tube 23. In addition, the particulate impurities falling from the surface of the filter tube 23 undergo shallow settling on the surface of the inclined plate 24 and slide down the inclined plate 24 to be collected in the conical mud collection chamber 22.

[0043] This embodiment 1 also provides another implementation method, specifically: the filtration system 2 further includes a drain valve 25; the drain valve 25 is located at the lowest point of the conical mud collection chamber 22, and is used to discharge the deposited particulate impurities collected in the conical mud collection chamber 22.

[0044] This embodiment 1 also provides another implementation method, specifically: the filtration system 2 further includes a turbidity measuring instrument 26; the turbidity measuring instrument 26 is set at the outlet end of the filter tube 23 and is used to measure the turbidity data of the water effluent from the filter tube 23.

[0045] This embodiment 1 also provides another implementation method, specifically: the device further includes a control unit; the input terminal of the control unit is connected to the output terminal of the turbidity measuring instrument 26, and the output terminal of the control unit is connected to the control terminal of the drain valve 25; the control unit is used to control the opening and closing of the drain valve 25 according to the turbidity data of the water effluent from the filter tube 23 and a preset drain control strategy.

[0046] Specifically, the control unit is connected to the drain valve 25 and the turbidity measuring instrument 26 via RS485 / Modbus-RTU protocol or industrial Ethernet protocol; optionally, when the injection valve 11 is an electrically controlled switching valve, the control unit is also connected to the injection valve 11 to realize the automatic opening and closing of the injection valve 11 and the flow rate regulation.

[0047] Explanatory, as attached Figure 2 As shown, the operation of the control unit is as follows: First, the turbidity data collected by the turbidity measuring instrument 26 is received according to a preset sampling period; then, the turbidity change slope is calculated; the calculation process of the turbidity change slope is as follows:

[0048] in, The slope of the turbidity change; This is turbidity data.

[0049] Subsequently, based on the turbidity data and turbidity change rate, and in conjunction with a preset sewage control strategy, the sewage valve 25 is controlled to open and close. Specifically, the turbidity data is compared with a preset turbidity threshold to obtain a turbidity comparison result; the turbidity change slope is compared with a preset slope threshold to obtain a slope comparison result; and based on the turbidity comparison result and the slope comparison result, a sewage control command is output to the sewage valve 25. The sewage control command is used to trigger the sewage valve 25 to adjust its opening, thereby controlling the opening and closing of the sewage valve 25.

[0050] It should be noted that the preset turbidity threshold includes the first turbidity threshold. Second turbidity threshold The preset slope thresholds include a first slope threshold. Second slope threshold Among them; the first turbidity threshold Less than the second turbidity threshold First slope threshold Less than the second slope threshold .

[0051] The preset pollution control strategy is a three-level judgment control, specifically including a first-level judgment control, a second-level judgment control, and a third-level judgment control, executed sequentially in the order of third-level judgment control, second-level judgment control, and first-level judgment control; the three-level judgment control is as follows: Level 1 Decision Control: When At that time, turbidity data Less than the first turbidity threshold And the absolute value of the slope of the turbidity change Less than the first slope threshold At this point, the system is determined to be in normal operating condition. The control unit generates and outputs a normal operating condition sewage discharge command, controlling the sewage discharge valve 25 at a fixed cycle. Sewage discharge is carried out, and the duration of a single discharge is [duration missing]. .

[0052] Second-level decision control: When At that time, turbidity data At the first turbidity threshold With the second turbidity threshold Between, or the absolute value of the slope of turbidity change At the first slope threshold With the second slope threshold During this period, it is determined to be a transitional operating condition. The control unit generates and outputs a transitional operating condition sewage discharge command, controlling the sewage discharge valve 25 to operate within the transition period. Sewage discharge is carried out, and the duration of a single discharge is [duration missing]. Among them, the transition period satisfy: and Duration of a single sewage discharge satisfy: .

[0053] Level 3 Decision Control: When At that time, turbidity data Not less than the second turbidity threshold or the absolute value of the slope of the turbidity change. Not less than the second slope threshold At this point, the system is determined to be in a high-pollution condition. The control unit generates and outputs a forced discharge command, controlling the drain valve 25 to perform a forced discharge cycle. Sewage discharge is carried out, and the duration of a single discharge is [duration missing]. Among them, the strong elimination cycle satisfy: and Duration of a single sewage discharge satisfy: .

[0054] Working principle: The draining device for protecting chemical instruments during unit startup, as described in Example 1, operates as follows: The sample water enters the sample inlet tube 1 through the sample inlet valve 11, and enters the bottom of the main cavity 21 of the system through the sample water throughlet 12 with the outlet end of the sample inlet tube 1 facing downward, and begins to flow from bottom to top.

[0055] Within the main cavity 21 of the system, the water sample flows from bottom to top, and with the help of several inclined plates 24, a multi-stage deflection and sedimentation structure is formed, so that the particulate impurities in the water sample settle and separate step by step under the action of gravity and inertia; the settled particulate impurities are collected in the conical mud collection cavity 22, realizing the efficient collection and isolation of particulate impurities.

[0056] After being decelerated by the inclined plate 24, the water sample flows upward to the top of the main cavity 21 of the system and is filtered through the horizontally set filter tube 23. When the water sample passes through the filter tube 23, particulate impurities in the sample water are trapped on the outer surface of the filter tube 23. When the particles accumulated on the outer surface reach a certain thickness, they naturally slide down to the inclined plate 24 below under the action of gravity, undergo shallow sedimentation on the surface of the inclined plate 24, and continue to slide down, collecting in the conical mud collection cavity 22. The clarified sample water flows out from the filtration system 2 and enters the external turbidity measuring instrument 26 for online detection. The measurement results are uploaded to the control unit in real time.

[0057] The control unit continuously calculates the turbidity change slope according to a preset sampling period, and performs a three-level judgment on the sewage discharge condition based on the collected turbidity data and the real-time value of the turbidity change slope; among them, when the water quality is good, a fixed period is used. Perform maintenance sludge discharge to prevent filter cartridge buildup; follow the transition cycle when water quality fluctuates. Adaptively shorten the sewage discharge cycle and extend the duration of each discharge; when water quality deteriorates rapidly, force discharge with the shortest fixed cycle. Continuous forced drainage rapidly reduces the load on the filtration system; smooth transitions between the three stages of judgment ensure that the drainage cycle meets requirements. This forms a complete closed-loop control system for water quality feedback.

[0058] The entire process requires no human intervention. The device drives the discharge action through turbidity data, and maintains the separation efficiency through the discharge action, thereby continuously ensuring the sample water quality of downstream online chemical instruments.

[0059] The wastewater discharge device for protecting chemical instruments during unit startup described in Embodiment 1 achieves a high proportion of interception of fine particles such as iron oxides in the sample water through the design of filter tube 23 and inclined plate 24. The device does not require manual intervention during unit startup. The control unit performs closed-loop adaptive wastewater discharge based on the feedback of water turbidity, which solves the problem of water quality contamination of online chemical instruments during startup. At the same time, it achieves wastewater discharge on demand, with significant water-saving effect and ensures the safe operation of key chemical equipment.

[0060] In this embodiment 1, the filter tube 23 is arranged horizontally. After the particles are trapped on the outer surface, they naturally slide off under the action of gravity, which fundamentally solves the problem of frequent clogging of traditional dead-end filters and realizes continuous online operation under unattended conditions. Secondly, the slope of turbidity change rather than the absolute value of turbidity is used as the core basis for sewage discharge decision-making. It can detect and respond in advance in the early stage of start-up when water quality changes drastically, and realize sewage discharge on demand. The entire start-up process of the unit is divided into three operating conditions, and a differentiated sewage discharge strategy is formulated for each level. The sewage discharge cycle and the duration of each discharge can be dynamically adjusted, which takes into account the high particle load handling capacity in the early stage of unit start-up and the water-saving performance in the normal operation stage.

[0061] Example 2 This embodiment 2 also provides a method for draining wastewater to protect chemical instruments during unit startup, which utilizes the draining method for protecting chemical instruments during unit startup described in embodiment 1 above, and includes the following steps: First, the sample water in the target water vapor system is transported to the bottom of the filtration system 2 using the sample inlet tube 1; after entering the filtration system 2, the sample water flows from bottom to top; when the sample water flows through the inclined plate 24 and the filter tube 23, the particulate impurities in the sample water are intercepted and separated, so that the clarified sample water enters the chemical instrument through the outlet of the filter tube 23. The trapped particulate impurities accumulate on the outer surface of the filter tube 23. When the accumulation thickness of the particulate impurities reaches the target value, they naturally slide down to the inclined plate 24 under the action of gravity, and after shallow settling on the surface of the inclined plate 24, they continue to slide down and collect in the conical mud collection cavity 22.

[0062] It should be noted that the principle of the draining method for protecting chemical instruments during unit startup described in Embodiment 2 is the same as the principle of the draining device for protecting chemical instruments during unit startup described in Embodiment 1 above, and will not be repeated here.

[0063] Engineering example illustration: The following examples illustrate the draining device and method for protecting chemical instruments during unit startup as described in the above embodiments, using specific engineering examples.

[0064] Engineering Example 1 In Example 1 of this project, the discharge process of condensate water sample during the first cold start of a 660MW supercritical coal-fired unit is taken as an example; the sample water flow rate is 500mL / min, the inlet turbidity is 120NTU, the iron content is 280μg / L, the temperature is 25℃, and the pressure is 0.4MPa.

[0065] The sample inlet tube has four downward-facing sample water through-holes at the bottom of its outlet; the filtration system uses six 5μm precision ceramic membrane filter tubes arranged horizontally; the inclined plate has an angle of 60° and a length of 60mm; in the control unit, the first turbidity threshold... Take 1 NTU, second turbidity threshold Take 10 NTU, first slope threshold Take 0.05 NTU / s as the second slope threshold. 0.19 NTU / s; fixed period Take 4 hours, duration of a single sewage discharge Take 5 seconds.

[0066] During the 0-30 minute startup period, the control unit monitored turbidity data. Not less than the second turbidity threshold The system is deemed to be in a high-pollution operating condition; at this time, the discharge cycle is adjusted according to... The calculation takes approximately 5 minutes; the drain valve operates at a forced discharge cycle. A short-cycle forced discharge is performed for 15 seconds after a single start-up; after 2 hours of startup, the turbidity at the device outlet stabilizes at 0.6-1.2 NTU, and the iron content is ≤18 μg / L.

[0067] Engineering Example 2 In Example 2 of this project, the process of discharging the feedwater sample from the deaerator outlet during the hot start-up of a 1000MW ultra-supercritical unit is taken as an example. The sample water flow rate is 800mL / min, the inlet turbidity is 4.5NTU, the iron content is 85μg / L, the temperature is 45℃, and the pressure is 0.6MPa.

[0068] The sample inlet tube has three downward-facing sample water through holes (φ2.5mm) at its outlet end; the filtration system uses four sintered stainless steel filter tubes with a precision of 10μm, arranged horizontally; the inclined plate has an angle of 55° and a length of 50mm; in the control unit, the first turbidity threshold... Take 0.5 NTU, second turbidity threshold Take 5 NTU, first slope threshold Take 0.02 NTU / s as the second slope threshold. Take 0.2 NTU / s; fixed period Take 8 hours, duration of a single sewage discharge Take 5 seconds.

[0069] During the 10-40 minute period of rapid load change, the control unit monitored turbidity data. At the first turbidity threshold With the second turbidity threshold Between these points, it is determined that the system has entered a transitional operating condition; at this time, the sewage discharge cycle is adjusted according to... Adaptive shortening, absolute value of the measured slope of turbidity change. ≈0.047 NTU / s, corresponding to a sewage discharge cycle of approximately 45 minutes; the sewage discharge valve operates on a transition cycle. The device is turned on for 10 seconds to discharge pollutants. After the operating conditions stabilize for 1 hour, the turbidity at the outlet of the device is stable at 0.2-0.4 NTU, and the iron content is ≤10 μg / L.

[0070] Engineering Example 3 In Example 3 of this project, the process of discharging the economizer inlet feedwater sample during the normal and stable operation of a 300MW subcritical unit is taken as an example. The sample water flow rate is 600mL / min, the inlet turbidity is 0.8NTU, the iron content is 15μg / L, the temperature is 35℃, and the pressure is 0.3MPa.

[0071] The bottom of the sample inlet tube has five φ1.5mm downward-facing sample water through holes; the filtration system uses five 20μm precision ceramic membrane filter tubes arranged horizontally; the inclined plate has an angle of 65° and a length of 80mm; in the control unit, the first turbidity threshold... Take 2 NTU, second turbidity threshold Take 15 NTU, first slope threshold Set the second slope threshold to 0.1 NTU / s. Take 0.8 NTU / s; fixed period Take 12 hours, duration of a single sewage discharge Take 5 seconds.

[0072] During continuous operation, the control unit monitored turbidity data. Less than the first turbidity threshold And the absolute value of the slope of the turbidity change Less than the first slope threshold At this point, it is determined that the system has entered normal operating condition, and the drain valve operates at a fixed cycle. Normal sewage discharge is performed within 5 seconds of a single start-up; the turbidity at the outlet of the device remains stable at 0.1-0.3 NTU and the iron content is ≤5 μg / L after 30 days of continuous operation.

[0073] Engineering Example 4 In Example 4 of this project, the process of discharging a water sample from a high-pressure boiler under sudden slight disturbance in a gas-steam combined cycle unit is taken as an example. The sample water flow rate is 400 mL / min, the inlet turbidity is 2.5 NTU, the iron content is 45 μg / L, the temperature is 40℃, and the pressure is 0.5 MPa.

[0074] The bottom of the sample inlet tube has four φ2mm downward-facing sample water through holes; the filtration system uses six sintered stainless steel filter tubes with a precision of 15μm, arranged horizontally; the inclined plate has an angle of 60° and a length of 70mm; in the control unit, the first turbidity threshold... Take 1 NTU, second turbidity threshold Take 8 NTU, first slope threshold Take 0.05 NTU / s as the second slope threshold. Take 0.4 NTU / s; fixed period Take 6 hours, duration of a single sewage discharge Take 5 seconds.

[0075] During the 0-20 minute period of a sudden water quality disturbance, the control unit monitors the absolute value of the slope of the turbidity change. At the first slope threshold With the second slope threshold Between these points, it is determined that the system has entered a transitional operating condition; at this time, the sewage discharge cycle is adjusted according to... Adaptive shortening, absolute value of the measured slope of turbidity change. ≈0.124 NTU / s, corresponding to a sewage discharge cycle of approximately 30 minutes; the sewage discharge valve operates on a transition cycle. The device is turned on for 8 seconds to discharge pollutants. After 1.5 hours of disturbance elimination, the turbidity at the outlet of the device recovers and stabilizes at 0.3-0.5 NTU, and the iron content is ≤12 μg / L.

[0076] Engineering Example 5 Example 5 of this project takes the discharge process of extremely high turbidity water sample from the mixed bed bypass of the condensate polishing of a 1000MW ultra-supercritical unit as an example; the sample water flow rate is 1000mL / min, the inlet turbidity is 350NTU, the iron content is 650μg / L, the temperature is 30℃, and the pressure is 0.8MPa.

[0077] The sample inlet tube has five downward-facing sample water through-holes at the bottom of its outlet; the filtration system uses eight 30μm precision ceramic membrane filter tubes arranged horizontally; the inclined plate has an angle of 65° and a length of 75mm; in the control unit, the first turbidity threshold... Take 2 NTU, second turbidity threshold Take 20 NTU, first slope threshold Set the second slope threshold to 0.1 NTU / s. 0.55 NTU / s; fixed period Take 8 hours, duration of a single sewage discharge Take 5 seconds.

[0078] During the 0-45 minute period of the sudden disturbance, the control unit monitored the absolute value of the slope of the turbidity change. Not less than the second slope threshold The system is deemed to be in a high-pollution operating condition; at this time, the discharge cycle is adjusted according to... The calculation takes approximately 2 minutes; the drain valve operates at a forced discharge cycle. A single start-up lasts 20 seconds for short-cycle forced discharge; after emergency discharge, the system recovers within 1 hour, with the turbidity at the device outlet controlled at 1.5-2.5 NTU and the iron content ≤25 μg / L.

[0079] The wastewater discharge device for protecting chemical instruments during unit startup, as described in this invention, can efficiently intercept and separate water vapor corrosion products such as iron oxides, and features low response lag, automatic wastewater discharge, on-demand adjustment, and maintenance-free online operation. The sample inlet outlet is located at the bottom of the main system cavity, allowing high-impurity water samples to enter at a low flow rate, where large particles initially settle under gravity. The inclined plates spaced apart in the middle and lower sections form multi-stage settling channels, effectively increasing the solid-liquid separation area and guiding suspended particles to slide down the plate surface to the lower conical sludge collection chamber for temporary storage, significantly reducing the impurity concentration of the upward-flowing water sample. After settling... The purified upper layer of clear liquid flows through the top filter tube for fine filtration before being supplied to the chemical instruments, fundamentally alleviating the risk of filter tube clogging under black water conditions. The conical sludge collection chamber facilitates the accumulation of impurities and allows for the periodic discharge of accumulated sludge through the bottom drain port. Impurity cleaning can be completed without disassembling core components, avoiding sampling interruptions and data distortion caused by clogging in traditional cartridge-type devices. It also significantly reduces the frequency of manual maintenance and the risk of delays, enabling the sampling pretreatment system to continuously output stable and clean water samples during the high-pollution phases of unit start-up and shutdown, effectively ensuring the reliability of chemical instrument monitoring and the safe operation of the unit.

[0080] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A draining device for protecting chemical instruments during unit startup, characterized in that, It includes a sample inlet tube (1) and a filtration system (2); the inlet end of the sample inlet tube (1) is used to connect to the sampling point of the target water vapor system, and the outlet end of the sample inlet tube (1) extends into the interior of the filtration system (2); The filtration system (2) includes a main system chamber (21), a conical mud collection chamber (22), a filter tube (23), and several inclined plates (24). The main cavity (21) of the system is connected vertically to the conical mud collection cavity (22). The outlet end of the sample inlet tube (1) extends to the bottom end of the main cavity (21). The filter tube (23) is horizontally arranged at the top end of the main cavity (21). The outlet end of the filter tube (23) extends to the outside of the main cavity (21) and is connected to the inlet of the chemical instrument. Several inclined plates (24) are inclinedly arranged in the lower middle part of the main cavity (21). The inclined plates (24) are spaced apart from each other.

2. A draining device for protecting chemical instruments during unit startup as described in claim 1, characterized in that, The bottom of the outlet end of the sample inlet tube (1) is provided with a plurality of sample water through holes (12); the plurality of sample water through holes (12) are evenly distributed along the axis of the sample inlet tube (1), and the opening of the sample water through holes (12) is provided facing the side of the conical mud collection chamber (22).

3. A draining device for protecting chemical instruments during unit startup as described in claim 1, characterized in that, The filter tube (23) is a ceramic membrane filter tube or a stainless steel sintered filter tube.

4. A draining device for protecting chemical instruments during unit startup as described in claim 1, characterized in that, The filtration accuracy of the filter tube (23) is 5-50μm.

5. A draining device for protecting chemical instruments during unit startup as described in claim 1, characterized in that, The angle between the inclined plate (24) and the horizontal plane is 55°-65°.

6. A draining device for protecting chemical instruments during unit startup as described in claim 1, characterized in that, The inlet end of the sample inlet tube (1) is also provided with a sample inlet valve (11); the sample inlet valve (11) is used to control the opening and closing of the sample inlet tube (1) and to adjust the sample water flow rate in the sample inlet tube (1).

7. A draining device for protecting chemical instruments during unit startup as described in claim 1, characterized in that, The filtration system (2) also includes a drain valve (25); the drain valve (25) is located at the lowest point of the conical mud collection chamber (22) and is used to discharge the sedimentary particulate impurities collected in the conical mud collection chamber (22).

8. A draining device for protecting chemical instruments during unit startup as described in claim 7, characterized in that, The filtration system (2) also includes a turbidity measuring instrument (26); the turbidity measuring instrument (26) is installed at the outlet end of the filter tube (23) and is used to measure the turbidity data of the water effluent from the filter tube (23).

9. A draining device for protecting chemical instruments during unit startup as described in claim 8, characterized in that, It also includes a control unit; the input terminal of the control unit is connected to the output terminal of the turbidity measuring instrument (26), and the output terminal of the control unit is connected to the control terminal of the drain valve (25); The control unit is used to control the opening and closing of the drain valve (25) according to the turbidity data of the water effluent from the filter tube (23) and a preset drain control strategy.

10. A method for draining wastewater to protect chemical instruments during unit startup, characterized in that, The method using the draining device for protecting chemical instruments during unit startup as described in any one of claims 1-9 includes: The sample water in the target water vapor system is transported to the bottom of the filtration system (2) using the sample inlet tube (1); after the sample water enters the filtration system (2), it flows from bottom to top; when the sample water flows through the inclined plate (24) and the filter tube (23), the particulate impurities in the sample water are intercepted and separated, so that the clarified sample water enters the chemical instrument through the outlet of the filter tube (23); Among them, the trapped particulate impurities accumulate on the outer surface of the filter tube (23); when the accumulation thickness of the particulate impurities reaches the target value, they naturally slide down to the inclined plate (24) under the action of gravity, and after shallow settling on the surface of the inclined plate (24), they continue to slide down and collect in the conical mud collection cavity (22).

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