Coal gasification black grey water monitoring system and method

Abstract

The invention discloses a coal gasification black and grey water monitoring system and method, and the system comprises a black water system provided with a washing tower, a gasification furnace and a flash evaporation unit, and a grey water system provided with a sedimentation unit and a backflow unit. The scaling monitoring device comprises a scaling testing unit used for detecting the scaling rate of grey water and a water quality detecting unit used for detecting grey water quality data, and the agent adding device comprises at least one flocculating agent adding unit and at least two dispersing agent adding units. The general control unit is used for adjusting the agent adding amount of the flocculating agent adding unit and the dispersing agent adding unit according to the ash water scaling rate and the ash water quality data. The scaling test unit and the water quality detection unit are installed in the grey water system for detection, and the general control unit adjusts the agent adding amount of the flocculant adding unit and the dispersing agent adding unit according to the detection result, so that the water quality of grey water can be dynamically adjusted in time; and the grey water scaling condition is improved under the condition that the normal operation of the system is not influenced.

Description

Technical Field

[0001] The present application relates to coal gasification black ash water treatment technology, and in particular to a coal gasification black ash water monitoring system and method. Background Art

[0002] The entrained-bed coal gasification process mainly includes coal grinding, coal gasification, black water flash evaporation and sedimentation, ash water treatment, coarse and fine slag discharge, etc. Considering the inherent characteristics of the gasification process, there are a large number of scaling ions, mainly calcium and magnesium ions, in the black ash water system, which leads to scaling, blockage, under-scale corrosion, etc. in the pipelines, pumps, heat exchangers and other equipment of the black ash water system, and then there are problems such as flow rate reduction, insufficient pumping, reduced heat exchange efficiency of heat exchangers, and equipment leakage, which seriously affect the stable operation of the coal gasification system. Therefore, the long-term stable operation of the black ash water system is very important for the normal operation of the coal gasification system. How to alleviate the scaling of the coal gasification black ash water system has become an urgent problem to be solved in the industry. Summary of the invention

[0003] The purpose of the present application is to overcome the deficiencies of the prior art and to provide a coal gasification black ash water monitoring system and method for improving the scaling condition by monitoring the scaling condition of the coal gasification black ash water and adjusting the dosage of the reagent.

[0004] The technical solution of the present application provides a coal gasification black ash water monitoring system, comprising:

[0005] The black water system comprises a washing tower, a gasifier and a flash unit which are connected in sequence, wherein the black water produced by the washing tower flows into the gasifier to participate in the reaction and then enters the flash unit for flash evaporation;

[0006] A grey water system, comprising a settling unit and a reflux unit connected in sequence to the black water system, wherein the black water is flashed in the flash unit, flows into the settling unit and settles into grey water, and then flows back to the washing tower through the reflux unit;

[0007] The scaling monitoring device comprises a scaling test unit for detecting the scaling rate of grey water and a water quality detection unit for detecting the water quality data of grey water, the settling unit and the return unit are each equipped with at least one scaling test unit, and the water quality detection unit is installed between the settling unit and the return unit;

[0008] The reagent adding device comprises at least one flocculant adding unit and at least two dispersant adding units, the grey water system is provided with at least one flocculant adding unit, and the black water system and the grey water system are each provided with at least one dispersant adding unit;

[0009] The main control unit is used to adjust the dosage of the flocculant addition unit and the dispersant addition unit according to the grey water scaling rate and the grey water quality data.

[0010] Further, the scaling test unit includes a water tank scaling test assembly and a pipeline scaling test assembly;

[0011] The sedimentation unit comprises a sedimentation tank and a multi-stage overflow tank which are sequentially connected to the flash unit, and the water tank scaling test assembly is detachably installed below the liquid level of the multi-stage overflow tank;

[0012] The reflux unit includes a low-pressure ash water pump, a deaerator and a high-pressure ash water pump which are sequentially connected to the multi-stage overflow tank. The pipeline between the multi-stage overflow tank and the low-pressure ash water pump and the pipeline between the deaerator and the high-pressure ash water pump are both installed with the pipeline scaling test assembly.

[0013] Further, the water tank scaling test assembly includes a fixing member and a first test piece connected to the fixing member through a connecting member, and the material of the first test piece is the same as that of the multi-stage overflow tank;

[0014] A mounting hole is provided on the top of each overflow trough in the multi-stage overflow trough, and a water tank scaling test assembly is installed in each mounting hole. The fixing part is detachably connected to the mounting hole, and the first test piece falls below the liquid surface of the multi-stage overflow trough.

[0015] Further, the pipeline scaling test assembly includes a test pipeline with connecting parts at both ends, a bracket installed in the test pipeline, and a second test piece installed on the bracket, and the material of the second test piece is the same as that of the tested pipeline;

[0016] The inner wall of the test pipe is provided with an installation groove along the circumferential direction. The bracket includes a support ring and a plurality of tie rods connected to one side of the support ring. The support ring is installed in the installation groove. One end of each of the tie rods is connected to the support ring, and the other end extends obliquely toward one axial side of the test pipe. The other ends of all the tie rods are connected as a support end. The second test piece is installed on the support end and each of the tie rods.

[0017] Further, the pipeline between the multi-stage overflow tank and the low-pressure gray water pump and the pipeline between the deaerator and the high-pressure gray water pump each include a first measured pipeline section and a second measured pipeline section, and the second measured pipeline section is connected in parallel to both ends of the first measured pipeline section;

[0018] The pipeline scaling test assembly is detachably installed in the first tested pipeline section and the second tested pipeline section. A first valve is installed at the water inlet end of the first tested pipeline section, and a second valve is installed at the water inlet end of the second tested pipeline section.

[0019] Furthermore, the sedimentation unit further comprises a sedimentation feed pump disposed between the flash unit and the sedimentation tank, and the flocculant adding unit is disposed between the sedimentation feed pump and the sedimentation tank.

[0020] Furthermore, a dispersant adding unit is respectively provided between the washing tower and the gasifier, between the multi-stage overflow tank and the low-pressure ash water pump, and between the deaerator and the high-pressure ash water pump.

[0021] Furthermore, a transparent observation pipe section is provided in the pipeline between the sedimentation tank and the multi-stage overflow tank.

[0022] The technical solution of the present application also provides a coal gasification black ash water monitoring method for the aforementioned coal gasification black ash water monitoring system, comprising:

[0023] Obtaining grey water quality data, and determining the grey water scaling tendency index based on the grey water quality data;

[0024] If the scaling tendency index is within a preset abnormal range, analyzing the scaling test unit to determine the grey water scaling rate;

[0025] The amount of reagent added by the flocculant adding unit or the dispersant adding unit is adjusted according to the scaling rate of the gray water.

[0026] Furthermore, the grey water quality data includes pH value, conductivity, total alkalinity, total hardness and maximum pipe surface temperature, and determining the grey water scaling tendency index according to the grey water quality data specifically includes:

[0027] The scaling tendency index is calculated according to the following formula:

[0028]

[0029] Among them, a, b, c are coefficients, T is the maximum surface temperature of the pipeline, J is the total alkalinity, H is the total hardness, and G is the conductivity.

[0030] Further, the scaling test unit is analyzed to determine the scaling rate of the grey water, specifically including:

[0031] Taking out the test piece in each fouling test unit for weight analysis to determine the mass increase of each test piece;

[0032] The mass increase is divided by the test piece area and the test days to obtain the scaling rate of each test piece;

[0033] The average scaling rate of all test pieces was calculated as the grey water scaling rate.

[0034] Further, each time after analyzing the scaling test unit to determine the scaling rate of the grey water, it also includes replacing the scaling test unit in the grey water system;

[0035] The step of adjusting the amount of the agent added by the flocculant adding unit or the dispersant adding unit according to the scaling rate of the ash water specifically includes:

[0036] If the scaling rate of the ash water is within the set scaling range, the amount of dispersant added is determined according to the scaling rate of the ash water, and the amount of reagent added by the dispersant adding unit is adjusted according to the amount of dispersant added;

[0037] After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate;

[0038] If the current scaling rate of the grey water is still within the set scaling range, the amount of flocculant added is determined according to the current scaling rate of the grey water, and the amount of agent added by the flocculant adding unit is adjusted according to the amount of flocculant added;

[0039] After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate;

[0040] If the current grey water scaling rate is still within the set scaling range, the reagent formula is adjusted.

[0041] Furthermore, the method of adjusting the amount of agent added by the flocculant adding unit or the dispersant adding unit according to the scaling rate of the grey water further includes:

[0042] If the scaling rate of the ash water is within the set corrosion range, the amount of dispersant reduction is determined according to the scaling rate of the ash water, and the amount of reagent added by the dispersant adding unit is adjusted according to the amount of dispersant reduction;

[0043] After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate;

[0044] If the current grey water scaling rate is still within the set corrosion range, the reagent formulation is adjusted.

[0045] After adopting the above technical solution, the following beneficial effects are achieved:

[0046] The present application installs a scaling test unit and a water quality detection unit in the grey water system for detection. The master control unit adjusts the dosage of the flocculant addition unit and the dispersant addition unit according to the detected grey water scaling rate and grey water quality data, thereby being able to dynamically adjust the grey water quality in a timely manner and improve the grey water scaling condition without affecting the normal operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The disclosure of this application will become easier to understand with reference to the accompanying drawings. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of this application. In the drawings:

[0048] Figure 1 It is a structural schematic diagram of a coal gasification black ash water monitoring system in one embodiment of the present application;

[0049] Figure 2 is a schematic diagram of the structure of a water tank scaling test assembly in one embodiment of the present application;

[0050] Figure 3 It is a structural schematic diagram of a pipeline scaling test assembly in one embodiment of the present application;

[0051] Figure 4 This is a schematic diagram of the structure of a transparent observation tube section in one embodiment of the present application;

[0052] Figure 5 This is a flow chart of a method for monitoring coal gasification black ash water in one embodiment of the present application;

[0053] Figure 6 It is a flow chart of a method for monitoring coal gasification black ash water in a preferred embodiment of the present application.

[0054] Reference table of reference numerals:

[0055] Scrubber 1, gasifier 2, water quality detection unit 3, flocculant addition unit 4, dispersant addition unit 5, high flash tank 6, low flash tank 7, true flash tank 8, water tank scaling test assembly 9, pipeline scaling test assembly 10, sedimentation tank 11, multi-stage overflow tank 12, low-pressure ash water pump 13, deaerator 14, high-pressure ash water pump 15, sedimentation feed pump 16, transparent observation pipe section 17;

[0056] The fixing member 091 , the connecting member 092 , the first test piece 093 , the test pipe 011 , the mounting groove 0111 , the connecting part 012 , the bracket 013 , the supporting ring 0131 , the tensioning rod 0132 , and the second test piece 014 . DETAILED DESCRIPTION

[0057] The specific implementation of the present application is further described below with reference to the accompanying drawings.

[0058] It is easy to understand that according to the technical solution of the present application, without changing the essential spirit of the present application, a variety of structural modes and implementation modes that can be replaced by those skilled in the art can be replaced with each other. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present application, and should not be regarded as the entirety of the present application or as a limitation or restriction on the technical solution of the application.

[0059] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to their different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0060] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above-mentioned in this application can be understood according to the specific circumstances.

[0061] Coal gasification black ash water monitoring system:

[0062] The coal gasification black ash water monitoring system in the embodiment of the present application is as follows: Figure 1 As shown, including:

[0063] The black water system comprises a washing tower 1, a gasifier 2 and a flash unit which are connected in sequence. The black water produced by the washing tower 1 flows into the gasifier 2 to participate in the reaction and then enters the flash unit for flash evaporation.

[0064] The grey water system comprises a settling unit and a reflux unit which are sequentially connected to the black water system. The black water is flashed in the flash unit, flows into the settling unit and settles into grey water, and then flows back to the washing tower 1 through the reflux unit.

[0065] The scaling monitoring device includes a scaling test unit for detecting the scaling rate of grey water and a water quality detection unit 3 for detecting the water quality data of grey water. The sedimentation unit and the return unit are each equipped with at least one scaling test unit, and the water quality detection unit 3 is installed between the sedimentation unit and the return unit.

[0066] The reagent adding device comprises at least one flocculant adding unit 4 and at least two dispersant adding units 5. The grey water system is provided with at least one flocculant adding unit 4, and the black water system and the grey water system are each provided with at least one dispersant adding unit 5.

[0067] The master control unit is used to adjust the dosage of the flocculant addition unit and the dispersant addition unit according to the scaling rate of the grey water and the grey water quality data.

[0068] Specifically, the washing tower 1 and the gasifier 2 are used to carry out coal gasification reaction to produce black water. The black water in the lower part of the washing tower 1 is pressurized by the quenching water pump and sent to the gasifier 2. The black water at the bottom of the quenching chamber of the gasifier 2 is discharged to the flash unit for flash evaporation. The flash unit includes a high flash tank 6, a low flash tank 7 and a true flash tank 8, wherein the true flash tank 8 is a two-stage true flash tank. The high flash tank 6, the low flash tank 7 and the true flash tank 8 perform primary flash evaporation, secondary flash evaporation, tertiary flash evaporation and quaternary flash evaporation on the black water discharged from the gasifier 2 in turn. The black water after the four-stage flash evaporation is discharged into the sedimentation unit of the gray water system. The sedimentation unit precipitates the black water to extract gray water, and then part of the gray water is refluxed to the washing tower 1 through the reflux unit to continue to participate in the reaction, so as to realize the recycling of gray water. In addition, part of the gray water is provided to the gasification unit and the coal slurry preparation unit, and the excess gray water is discharged from the system as wastewater.

[0069] In the embodiment of the present application, a scaling test unit and a water quality detection unit 3 are provided in the grey water system. The scaling test unit is used to detect the scaling rate of the grey water. A test piece of the same material as the test point can be installed at the test point, and the scaling rate of the grey water can be determined by detecting the scaling condition of the test piece. Since the scaling conditions in different areas of the grey water system are different, scaling test units are provided in both the sedimentation unit and the return unit for detection, thereby improving the accuracy of the detection of the scaling rate of the grey water. The water quality detection unit 3 is used to detect the water quality data of the grey water. A sensor corresponding to the water quality data can be installed at the test point for detection. Since the grey water is no longer processed after flowing into the return unit, the water quality detection unit 3 can be provided before the return unit for detection.

[0070] The system is provided with a flocculant adding unit 4 and a dispersant adding unit 5 to add flocculants and dispersants respectively. The dispersant is a conventional agent for improving scaling, so at least one dispersant adding unit 5 is provided in the black water system and the gray water system; the flocculant is a strong agent for improving scaling, so it can be provided only in the gray water system. The flocculant adding unit 4 and the dispersant adding unit 5 both include an agent storage tank and an agent inlet pipeline, and an agent regulating valve is installed on the agent inlet pipeline, and the agent addition rate is adjusted by adjusting the opening of the agent regulating valve.

[0071] The master control unit adjusts the opening of the agent regulating valve on the flocculant adding unit 4 and the dispersant adding unit 5 according to the preset program by obtaining the scaling rate and quality data of the gray water detected by the scaling monitoring device, so as to adjust the addition rate of the flocculant and the dispersant. The scaling rate and quality data of the gray water can be input by the staff after detection, or can be automatically obtained through the communication connection between the master control unit and the scaling monitoring device.

[0072] In the embodiment of the present application, a scaling test unit and a water quality detection unit are installed in the grey water system for detection. The main control unit adjusts the dosage of the flocculant addition unit 4 and the dispersant addition unit 5 according to the detected grey water scaling rate and grey water quality data, so as to dynamically adjust the grey water quality in a timely manner and improve the scaling of the grey water without affecting the normal operation of the system.

[0073] In one embodiment, the scaling test unit includes a water tank scaling test assembly 9 and a pipe scaling test assembly 10;

[0074] The sedimentation unit comprises a sedimentation tank 11 and a multi-stage overflow tank 12 which are sequentially connected to the flash unit, and the water tank scaling test assembly 9 is detachably installed below the liquid level of the multi-stage overflow tank 12;

[0075] The reflux unit includes a low-pressure ash water pump 13, a deaerator 14 and a high-pressure ash water pump 15 which are sequentially connected to the multi-stage overflow tank 12. The pipeline between the multi-stage overflow tank 12 and the low-pressure ash water pump 13 and the pipeline between the deaerator 14 and the high-pressure ash water pump 15 are both installed with a pipeline scaling test assembly 10.

[0076] Specifically, the black water after the four-stage flash evaporation first enters the sedimentation tank 11 for sedimentation, and the upper clarified water is input into the multi-stage overflow tank 12. The multi-stage overflow tank 12 is provided with 3-4 levels of overflow tanks. The upper clarified water of each overflow tank flows into the next overflow tank in turn for sedimentation, and the solid matter in the gray water settles to the bottom of the overflow tank and is sent to the filtration system through the sewage pipe. The upper clarified gray water of the multi-stage overflow tank 12 is pressurized by the low-pressure gray water pump and then transported to the deaerator 14. The gray water of the deaerator 14 is further pressurized by the high-pressure gray water pump and then sent to the gasifier quenching chamber for recycling.

[0077] The water tank scaling test assembly 9 is installed in the multi-stage overflow tank 12. Multiple water tank scaling test assemblies 9 can be set in the multi-stage overflow tank 12 to detect the scaling rate of gray water in different parts. The water tank scaling test assembly 9 is detachably installed, which is convenient for removal to detect the scaling situation and determine the scaling rate of gray water. The pipeline scaling test assembly 10 is installed in the pipeline and can be detachably connected to the pipeline for easy removal and detection.

[0078] In the embodiment of the present application, the pipeline scaling test assembly 10 is installed at two nodes before the low-pressure gray water pump 13 and the high-pressure gray water pump 15, respectively, and the water tank scaling test assembly 9 in the multi-stage overflow tank 12 is added to realize the detection of each important node in the gray water system.

[0079] In one embodiment, if Figure 2 As shown, the water tank scaling test assembly 9 includes a fixing member 091 and a first test piece 093 connected below the fixing member 091 through a connecting member 092. The material of the first test piece 093 is the same as that of the multi-stage overflow tank 12.

[0080] A mounting hole is provided at the top of each overflow tank in the multi-stage overflow tank 12. A water tank scaling test assembly 9 is installed in each mounting hole. The fixing piece 091 is detachably connected to the mounting hole. The first test piece 093 falls below the liquid surface of the multi-stage overflow tank.

[0081] Specifically, each overflow tank in the multi-stage overflow tank 12 is equipped with a water tank scaling test assembly 9, and a mounting hole is opened on the top of the multi-stage overflow tank 12, and each mounting hole is located above the first overflow tank. The fixing member 091 of the water tank scaling test assembly 9 is detachably installed in the mounting hole, and can be connected by flange connection, clamping connection or screw connection. A first test piece 093 is connected to the bottom of the fixing member 091 through a connecting member 092; the first test piece 093 can be set to a fixed size, for example, the length, width and height are set to 5cm, 2.5cm and 0.3cm respectively; the connecting member 092 can use a pull rope, etc., to lower the first test piece 093 below the liquid level of the overflow tank of this level, preferably extending to a position 20%-50% below the liquid level.

[0082] In one embodiment, if Figure 3 As shown, the pipeline scaling test assembly 10 includes a test pipeline 011 with connecting parts 012 at both ends, a bracket 013 installed in the test pipeline 011, and a second test piece 014 installed on the bracket 013. The material of the second test piece 014 is the same as that of the tested pipeline;

[0083] The inner wall of the test pipe 011 is provided with an installation groove 0111 along the circumferential direction. The bracket 013 includes a support ring 0131 and a plurality of tie rods 0132 connected to one side of the support ring 0131. The support ring 0131 is installed in the installation groove 0111. One end of each tie rod 0132 is connected to the support ring 0131, and the other end extends obliquely toward one axial side of the test pipe 011. The other ends of all the tie rods 0132 are connected as a support end. A second test piece 014 is installed on the support end and each tie rod 0132.

[0084] Specifically, the test pipe 011 is connected to the tested pipe through the connecting parts 012 at both ends. The connecting parts 012 can be set as connecting flanges, which can ensure the sealing performance and facilitate disassembly and assembly. The diameter of the test pipe 011 is the same as the diameter of the tested pipe. The installation groove 0111 is an annular groove 0111. The thickness of the support ring 0131 of the bracket 013 is the same as the depth of the installation groove 0111, so that the inner wall of the support ring 0131 is flush with the inner wall of the test pipe 011 after installation, so as not to affect the gray water flow rate and cause the gray water scaling rate in this area to be different from other areas in the tested pipe. The number of tie bars 0132 can be set according to actual conditions. The tie bars 0132 are evenly arranged around the support ring 0131. The end of the tie bars 0132 away from the support ring 0131 is connected as a support end. Preferably, the support end is located on the axis of the test pipe 011. The tie bars 0132 form a 30° inclination angle with the axis of the test pipe 011, so that the overall structure of the bracket 013 is more stable.

[0085] A second test piece 014 is installed on the support end and each tie rod 0132. A second test piece 014 can be installed on the tie rod 0132 at each set interval. The set interval distance and the size of the second test piece 014 can be adjusted as needed so that adjacent second test pieces 014 have no overlapping parts in the axial direction of the test pipe 011 to reduce the impact on the water flow.

[0086] The pipeline scaling test assembly 10 in the embodiment of the present application is detachably installed in the pipeline to be tested. During testing, the entire test pipeline 011 is removed and the second test piece 014 is taken out for testing.

[0087] In one embodiment, if Figure 1 As shown, the pipeline between the multi-stage overflow tank 12 and the low-pressure gray water pump 13 and the pipeline between the deaerator 14 and the high-pressure gray water pump 15 both include a first tested pipeline section and a second tested pipeline section, and the second tested pipeline section is connected in parallel at both ends of the first tested pipeline section;

[0088] The first tested pipeline section and the second tested pipeline section are both detachably installed with pipeline scaling test components 10, the water inlet end of the first tested pipeline section is installed with a first valve, and the water inlet end of the second tested pipeline section is installed with a second valve.

[0089] In the embodiment of the present application, a first tested pipeline section and a second tested pipeline section are arranged in parallel in the pipeline where the pipeline scaling test assembly 10 is installed, and a first valve and a second valve are installed at the water inlet end respectively. Each time the system is running, only the first valve or the second valve is opened, and only one of the tested pipeline sections is conducted. Specifically, after the first tested pipeline section has been put into operation for a period of time, the pipeline scaling test assembly 10 needs to be removed for inspection. Then, a new pipeline scaling test assembly 10 is first installed in the second tested pipeline section, and then the second valve is opened and the first valve is closed, and then the pipeline scaling test assembly 10 in the first tested pipeline section is removed, so that the structural test assembly 10 can be disassembled and assembled without affecting the operation of the system.

[0090] In one embodiment, the sedimentation unit further includes a sedimentation feed pump 16 disposed between the flash unit and the sedimentation tank 11 , and the flocculant addition unit 4 is disposed between the sedimentation feed pump 16 and the sedimentation tank 11 .

[0091] Specifically, the black water after four-stage flash evaporation in the true flash tank 8 is pumped into the sedimentation tank 11 through the sedimentation feed pump 16, and the flocculant adding unit 4 is arranged between the sedimentation tanks 11. After the flocculant is added to the black water, it enters the sedimentation tank 11 for sedimentation, and the sedimentation efficiency is higher.

[0092] In one embodiment, a dispersant adding unit 5 is provided between the scrubber 1 and the gasifier 2 , between the multi-stage overflow tank 12 and the low-pressure ash water pump 13 , and between the deaerator 14 and the high-pressure ash water pump 15 .

[0093] In the embodiment of the present application, three dispersant adding units 5 are provided, one is provided in the black water system and is located between the washing tower 1 and the gasifier 2, and two are provided in the gray water system, which are respectively located between the multi-stage overflow tank 12 and the low-pressure gray water pump 13, and between the deaerator 14 and the high-pressure gray water pump 15, wherein the dispersant adding unit 5 between the multi-stage overflow tank 12 and the low-pressure gray water pump 13 is located at the outlet of the multi-stage overflow tank 12, and the water quality detection unit 3 and the pipeline scaling test assembly 10 are located after the dispersant adding unit 5.

[0094] In one embodiment, if Figure 1 , 4 As shown, a transparent observation pipe section 17 is provided in the pipeline between the sedimentation tank 11 and the multi-stage overflow tank 12.

[0095] The transparent observation pipe section 17 is made of glass, transparent resin or other materials, and its two ends are connected to the pipeline through connecting flanges, so that the staff can observe the water quality of the gray water through the transparent observation pipe section 17 .

[0096] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0097] Coal gasification black ash water monitoring method:

[0098] The coal gasification black ash water monitoring method in the embodiment of the present application is used in the aforementioned coal gasification black ash water monitoring system, such as Figure 5 As shown in the figure, the coal gasification black ash water monitoring method includes:

[0099] Step S501: obtaining grey water quality data, and determining a grey water scaling tendency index according to the grey water quality data;

[0100] Step S502: if the scaling tendency index is within a preset abnormal range, the scaling test unit is analyzed to determine the scaling rate of the grey water;

[0101] Step S503: adjusting the dosage of the flocculant adding unit or the dispersant adding unit according to the scaling rate of the grey water.

[0102] Specifically, the scaling tendency index of grey water is first determined through the grey water quality data to evaluate the scaling tendency of the system. When the scaling tendency index is within the preset abnormal range, the scaling rate of grey water is further analyzed through the scaling test unit. The amount of reagent added by the flocculant addition unit or the dispersant addition unit is adjusted according to the grey water scaling rate, with only one reagent adjusted at a time.

[0103] In the embodiment of the present application, since the grey water quality data can be monitored in real time, while the detection of the grey water scaling rate requires a relatively long time, the grey water scaling tendency index is first detected. When the value is within a preset abnormal range, the scaling test unit is removed to analyze the grey water scaling rate. The amount of reagent added is adjusted according to the grey water scaling rate. This can not only timely adjust the scaling tendency of the grey water, but also simplify the test process to a certain extent.

[0104] In one embodiment, the grey water quality data includes pH value, conductivity, total alkalinity, total hardness and maximum pipe surface temperature, and the grey water scaling tendency index is determined according to the grey water quality data, specifically including:

[0105] The scaling tendency index is calculated according to the following formula:

[0106]

[0107] Among them, a, b, c are coefficients, T is the maximum surface temperature of the pipeline, J is the total alkalinity, H is the total hardness, and G is the conductivity.

[0108] The coefficients a, b, and c are determined based on the previous experimental data. For reference, the coefficient a is 12.07-12.57, the coefficient b is 0.016-0.018, and the coefficient c is 0.70-0.80. The maximum surface temperature of the pipeline is the maximum temperature of the pipeline surface detected at the detection point.

[0109] The embodiment of the present application combines the pH value, conductivity, total alkalinity, total hardness and maximum surface temperature of the pipeline of the grey water to comprehensively calculate the grey water scaling tendency index, which can comprehensively analyze the scaling tendency.

[0110] Based on the calculation method of the scaling tendency index in the embodiment of the present application, the aforementioned preset abnormal range can be set to 6.0-6.5 and 7.5-8.0. When the scaling tendency index is 6.0-6.5, it indicates that it is in a scaling state at this time, and the smaller the value, the more serious the scaling tendency; when the scaling tendency index is 7.5-8.0, it indicates that it is in a weak acid corrosion state at this time, and the larger the value, the more serious the corrosion tendency; when the scaling tendency index is between 6.5-7.0, it is a weak alkaline stable state, and the system is in a scaling dynamic equilibrium state; when the scaling tendency index is between 7.0-7.5, it is a weak acid stable state, and the system is in a corrosion dynamic equilibrium state.

[0111] In one embodiment, analyzing the scaling test unit to determine the scaling rate of the grey water includes:

[0112] Taking out the test piece in each fouling test unit for weight analysis to determine the mass increase of each test piece;

[0113] The mass increase was divided by the test piece area and the number of test days to obtain the fouling rate of each test piece;

[0114] The average scaling rate of all test pieces was calculated as the grey water scaling rate.

[0115] Specifically, the scaling test unit places a test piece with the same material as the test point in the system. After a certain period of time, the test piece and the pipe in the system will scale synchronously. Therefore, when determining the scaling rate of gray water, it is necessary to take out the test piece in the system, subtract the initial mass of the test piece from the current mass of the test piece to get the mass increase of the test piece, and divide the mass increase by the area of ​​the test piece and the number of test days to get the scaling rate of each test piece. Then, the average scaling rate of all test pieces is calculated as the gray water scaling rate of the system, so that the value of the gray water scaling rate can more accurately reflect the scaling rate of the system.

[0116] It should be noted that the mass increase of the test piece can be a positive value or a negative value. When the mass increase is a positive number, it indicates that the grey water is in a scaling state. When the mass increase is a negative value, it indicates that the grey water is in a corrosive state.

[0117] In one embodiment, each time after analyzing the scaling test unit to determine the scaling rate of the grey water, the method further includes replacing the scaling test unit in the grey water system;

[0118] Adjust the dosage of the flocculant addition unit or dispersant addition unit according to the scaling rate of the gray water, including:

[0119] If the scaling rate of the ash water is within the set scaling range, the amount of dispersant added is determined according to the scaling rate of the ash water, and the amount of reagent added in the dispersant adding unit is adjusted according to the amount of dispersant added;

[0120] After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate;

[0121] If the current scaling rate of the grey water is still within the set scaling range, the amount of flocculant added is determined according to the current scaling rate of the grey water, and the amount of agent added in the flocculant adding unit is adjusted according to the amount of flocculant added;

[0122] After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate;

[0123] If the current grey water scaling rate is still within the set scaling range, adjust the reagent formula.

[0124] The present application example analyzes the case where the scaling rate of gray water is positive, and sets the scaling range to 50-200 mg / (m 2 *d). When the scaling rate of ash water is less than 50mg / (m 2 *d), the scaling rate of the ash water is in a normal state, and the ash water is in a dynamic balance, so there is no need to adjust the amount of reagent added. The scaling range is divided into multiple intervals, and different dispersant addition amounts are set for different intervals. Specifically: when the scaling rate of the ash water is 50-100mg / (m 2 *d), the amount of dispersant added is 10% of the original dispersant dosage; when the scaling rate of ash water is 100-200mg / (m 2 *d), the amount of dispersant added is 30%-50% of the original amount of dispersant. After the amount of dispersant added is determined, the amount of agent added in the dispersant adding unit is adjusted according to the amount of dispersant added.

[0125] At this point, the first stage of reagent adjustment is completed. After waiting for the set adjustment time, take out the replaced scaling test unit for analysis to determine the current gray water scaling rate. The set adjustment time can be adjusted according to the observed gray water quality, or it can be set to a fixed value, which is determined according to actual production needs. If the current gray water scaling rate is still within the set scaling range, it means that the effect of the dispersant adjustment is not good. At this time, the amount of flocculant increase is determined according to the current gray water scaling rate, and the amount of reagent added in the flocculant addition unit is adjusted. The amount of flocculant added can be set to a fixed value or set according to different retaining wall gray water scaling rates.

[0126] At this point, the second stage of reagent adjustment is completed. After waiting for the set time, take out the replaced scaling test unit for analysis to determine the current gray water scaling rate. If the current gray water scaling rate is still within the set scaling range, it means that the adjustment of the reagent dosage has not improved the scaling well. At this time, the reagent formula of the dispersant or flocculant needs to be adjusted, and an alarm signal can be issued to remind the staff.

[0127] The embodiment of the present application adjusts the dispersant addition amount, the flocculant addition amount and the agent formula in sequence according to the scaling rate of the ash water, and can adjust the agent according to the scaling situation to effectively improve the scaling problem.

[0128] In one embodiment, adjusting the amount of agent added by the flocculant adding unit or the dispersant adding unit according to the scaling rate of the gray water further includes:

[0129] If the scaling rate of the ash water is within the set corrosion range, the amount of dispersant reduction is determined according to the scaling rate of the ash water, and the amount of reagent added by the dispersant adding unit is adjusted according to the amount of dispersant reduction;

[0130] After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate;

[0131] If the current grey water scaling rate is still within the set corrosion range, adjust the reagent formula.

[0132] The present embodiment analyzes the case where the scaling rate of gray water is negative, and sets the scaling range to (-50)-(-5) mg / (m 2 *d). When the scaling rate of ash water is greater than -5mg / (m 2 *d), the gray water corrosion rate is in a normal state, the gray water is in dynamic balance, and there is no need to adjust the amount of reagent added. The corrosion range is divided into multiple intervals, and different dispersant reduction amounts are set for different intervals. Specifically: when the gray water scaling rate is (-50)-(-10) mg / (m 2 *d), the amount of dispersant reduced is 10%-30% of the original dispersant dosage; when the scaling rate of ash water is (-10)-(-5)mg / (m 2 *d), the amount of dispersant added is less than 10% of the original amount of dispersant. After the amount of dispersant added is determined, the amount of reagent added in the dispersant adding unit is adjusted according to the amount of dispersant added.

[0133] After that, continue to wait for the set time, take out the replaced scaling test unit for analysis to determine the current scaling rate of the ash water. If the current scaling rate of the ash water is still within the set corrosion range, it means that the adjustment of the dosage does not improve the corrosion well. At this time, the dosage formula of the dispersant or flocculant needs to be adjusted, and an alarm signal can be issued to remind the staff.

[0134] Figure 6 The flowchart of the coal gasification black ash water monitoring method in a preferred embodiment of the present application is shown, which specifically includes:

[0135] Step S601: Obtain grey water quality data, and determine the grey water scaling tendency index according to the grey water quality data, specifically:

[0136] The scaling tendency index is calculated according to the following formula:

[0137]

[0138] Among them, a, b, c are coefficients, T is the maximum surface temperature of the pipeline, J is the total alkalinity, H is the total hardness, and G is the conductivity.

[0139] Step S602: If the scaling tendency index is within the preset abnormal range, the test piece in each scaling test unit is taken out for weight analysis to determine the mass increase of each test piece.

[0140] Step S603: Divide the mass increase by the test piece area and the test days to obtain the scaling rate of each test piece.

[0141] Step S604: Calculate the average scaling rate of all test pieces as the grey water scaling rate.

[0142] Step S605: If the scaling rate of the grey water is within the set scaling range, execute step S606; if the scaling rate of the grey water is within the set corrosion range, execute step S611.

[0143] Step S606: determining the amount of dispersant added according to the scaling rate of the grey water, and adjusting the amount of agent added by the dispersant adding unit according to the amount of dispersant added.

[0144] Step S607: After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate.

[0145] Step S608: If the current grey water scaling rate is still within the set scaling range, the amount of flocculant added is determined according to the current grey water scaling rate, and the amount of agent added by the flocculant adding unit is adjusted according to the amount of flocculant added.

[0146] Step S609: After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate.

[0147] Step S610: If the current grey water scaling rate is still within the set scaling range, adjust the reagent formula.

[0148] Step S611: determining the amount of dispersant reduction according to the scaling rate of the grey water, and adjusting the amount of agent added by the dispersant adding unit according to the amount of dispersant reduction.

[0149] Step S612: After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate.

[0150] Step S613: If the current grey water scaling rate is still within the set corrosion range, adjust the reagent formula.

[0151] The above description is only the principle and preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this field, the implementation methods obtained by appropriately combining the technical solutions disclosed in different embodiments are also included in the technical scope of the present invention. On the basis of the principle of the present application, several other variations can be made, which should also be regarded as the protection scope of the present application.

Claims

1. A coal gasification black ash water monitoring system, characterized in that: include: The black water system comprises a washing tower, a gasifier and a flash unit which are connected in sequence, wherein the black water produced by the washing tower flows into the gasifier to participate in the reaction and then enters the flash unit for flash evaporation; A grey water system, comprising a settling unit and a reflux unit connected in sequence to the black water system, wherein the black water is flashed in the flash unit, flows into the settling unit and settles into grey water, and then flows back to the washing tower through the reflux unit; The scaling monitoring device comprises a scaling test unit for detecting the scaling rate of grey water and a water quality detection unit for detecting the water quality data of grey water, the settling unit and the return unit are each equipped with at least one scaling test unit, and the water quality detection unit is installed between the settling unit and the return unit; The reagent adding device comprises at least one flocculant adding unit and at least two dispersant adding units, the grey water system is provided with at least one flocculant adding unit, and the black water system and the grey water system are each provided with at least one dispersant adding unit; The main control unit is used to adjust the dosage of the flocculant addition unit and the dispersant addition unit according to the scaling rate of the grey water and the grey water quality data.

2. The coal gasification black ash water monitoring system according to claim 1 is characterized in that: The scaling test unit includes a water tank scaling test assembly and a pipeline scaling test assembly; The sedimentation unit comprises a sedimentation tank and a multi-stage overflow tank which are sequentially connected to the flash unit, and the water tank scaling test assembly is detachably installed below the liquid level of the multi-stage overflow tank; The reflux unit includes a low-pressure ash water pump, a deaerator and a high-pressure ash water pump which are sequentially connected to the multi-stage overflow tank. The pipeline between the multi-stage overflow tank and the low-pressure ash water pump and the pipeline between the deaerator and the high-pressure ash water pump are both installed with the pipeline scaling test assembly.

3. The coal gasification black ash water monitoring system according to claim 2 is characterized in that: The water tank scaling test assembly includes a fixing member and a first test piece connected to the fixing member through a connecting member, wherein the material of the first test piece is the same as that of the multi-stage overflow tank; A mounting hole is provided on the top of each overflow trough in the multi-stage overflow trough, and a water tank scaling test assembly is installed in each mounting hole. The fixing part is detachably connected to the mounting hole, and the first test piece falls below the liquid surface of the multi-stage overflow trough.

4. The coal gasification black ash water monitoring system according to claim 2, characterized in that: The pipeline scaling test assembly includes a test pipeline with connecting parts at both ends, a bracket installed in the test pipeline, and a second test piece installed on the bracket, wherein the material of the second test piece is the same as that of the tested pipeline; The inner wall of the test pipe is provided with an installation groove along the circumferential direction. The bracket includes a support ring and a plurality of tie rods connected to one side of the support ring. The support ring is installed in the installation groove. One end of each of the tie rods is connected to the support ring, and the other end extends obliquely toward one axial side of the test pipe. The other ends of all the tie rods are connected as a support end. The second test piece is installed on the support end and each of the tie rods.

5. The coal gasification black ash water monitoring system according to claim 4, characterized in that: The pipeline between the multi-stage overflow tank and the low-pressure gray water pump and the pipeline between the deaerator and the high-pressure gray water pump both include a first tested pipeline section and a second tested pipeline section, and the second tested pipeline section is connected in parallel to both ends of the first tested pipeline section; The pipeline scaling test assembly is detachably installed in the first tested pipeline section and the second tested pipeline section. A first valve is installed at the water inlet end of the first tested pipeline section, and a second valve is installed at the water inlet end of the second tested pipeline section.

6. The coal gasification black ash water monitoring system according to claim 2, characterized in that: The sedimentation unit further includes a sedimentation feed pump disposed between the flash unit and the sedimentation tank, and the flocculant adding unit is disposed between the sedimentation feed pump and the sedimentation tank.

7. The coal gasification black ash water monitoring system according to claim 2, characterized in that: A dispersant adding unit is respectively provided between the washing tower and the gasifier, between the multi-stage overflow tank and the low-pressure ash water pump, and between the deaerator and the high-pressure ash water pump.

8. The coal gasification black ash water monitoring system according to any one of claims 2 to 7, characterized in that: A transparent observation pipe section is provided in the pipeline between the sedimentation tank and the multi-stage overflow tank.

9. A method for monitoring coal gasification black ash water used in the coal gasification black ash water monitoring system according to any one of claims 1 to 8, characterized in that: include: Obtaining grey water quality data, and determining the grey water scaling tendency index based on the grey water quality data; If the scaling tendency index is within a preset abnormal range, analyzing the scaling test unit to determine the grey water scaling rate; The amount of reagent added by the flocculant adding unit or the dispersant adding unit is adjusted according to the scaling rate of the gray water.

10. The method for monitoring coal gasification black ash water according to claim 9, characterized in that: The grey water quality data include pH value, conductivity, total alkalinity, total hardness and maximum pipe surface temperature. The grey water scaling tendency index is determined based on the grey water quality data, specifically including: The scaling tendency index is calculated according to the following formula: Among them, a, b, c are coefficients, T is the maximum surface temperature of the pipeline, J is the total alkalinity, H is the total hardness, and G is the conductivity.

11. The method for monitoring coal gasification black ash water according to claim 9, characterized in that: The analyzing the scaling test unit to determine the scaling rate of the grey water specifically includes: Taking out the test piece in each fouling test unit for weight analysis to determine the mass increase of each test piece; The mass increase is divided by the test piece area and the test days to obtain the scaling rate of each test piece; The average scaling rate of all test pieces was calculated as the grey water scaling rate.

12. The method for monitoring coal gasification black ash water according to claim 9, characterized in that: After each analysis of the scaling test unit to determine the scaling rate of the grey water, it also includes replacing the scaling test unit in the grey water system; The step of adjusting the amount of the agent added by the flocculant adding unit or the dispersant adding unit according to the scaling rate of the ash water specifically includes: If the scaling rate of the ash water is within the set scaling range, the amount of dispersant added is determined according to the scaling rate of the ash water, and the amount of reagent added by the dispersant adding unit is adjusted according to the amount of dispersant added; After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate; If the current scaling rate of the grey water is still within the set scaling range, the amount of flocculant added is determined according to the current scaling rate of the grey water, and the amount of agent added by the flocculant adding unit is adjusted according to the amount of flocculant added; After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate; If the current grey water scaling rate is still within the set scaling range, the reagent formula is adjusted.

13. The method for monitoring coal gasification black ash water according to claim 12, characterized in that: The step of adjusting the amount of the agent added by the flocculant adding unit or the dispersant adding unit according to the scaling rate of the ash water further includes: If the scaling rate of the ash water is within the set corrosion range, the amount of dispersant reduction is determined according to the scaling rate of the ash water, and the amount of reagent added by the dispersant adding unit is adjusted according to the amount of dispersant reduction; After the set adjustment time, the replaced scaling test unit is analyzed to determine the current grey water scaling rate; If the current grey water scaling rate is still within the set corrosion range, the reagent formulation is adjusted.

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