A wastewater drying effect detection system and method

Abstract

The present invention provides a wastewater drying effect detection system and method. The wastewater drying effect detection system of the present invention includes a drying tower, an atomizer is provided at the top of the drying tower, the atomizer is communicated with a wastewater pipeline, a wastewater regulating valve is provided on the wastewater pipeline, an inlet flue and an outlet flue are respectively provided in the upper and lower parts of the drying tower, a flue gas regulating valve is provided on the inlet flue, detection devices are respectively and parallelly provided on the inlet flue and the outlet flue, the detection device includes a smoke inlet pipe, a smoke transmission pipe and an ash transmission pipe, a valve and a filter are successively provided on the smoke inlet pipe, the smoke outlet and the ash outlet of the filter are respectively communicated with the smoke transmission pipe and the ash transmission pipe, a fan is provided on the smoke transmission pipe, an ash accumulator and a weight sensor are successively provided at the outlet end of the ash transmission pipe. The system and method of the present invention can quickly detect the moisture content of flue gas ash, accurately judge the evaporation and drying effect of wastewater, which is beneficial to reducing the system energy consumption and ensuring the stable operation of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular, to a wastewater drying effect detection system and method. Background Art

[0002] The high-temperature flue gas drying technology atomizes wastewater and sprays it into a drying tower, and at the same time sprays high-temperature flue gas from a thermal power plant into the drying tower. The wastewater is evaporated and dried by making full contact between the high-temperature flue gas and the wastewater droplets to achieve zero discharge of wastewater. It has advantages such as a simple process flow and low operation cost. However, the temperature of the high-temperature flue gas in a thermal power plant usually fluctuates to some extent. The temperature of the high-temperature flue gas entering the drying tower is unstable and not easy to control. When using this high-temperature flue gas to evaporate and dry wastewater, there are problems such as unstable evaporation effect, wet ash, blockage, corrosion and other failures caused by poor evaporation, which not only have a serious adverse impact on the normal operation of the system, but also may have problems such as excessive energy consumption waste.

[0003] CN 216997750 U discloses a zero-discharge system for high-salt wastewater high-temperature flue gas evaporation drying with anti-ash accumulation, including: a first dust collector; a deflector installed inside the first dust collector; a first ash hopper installed at the bottom of the first dust collector; a first bin pump installed at the bottom of the first ash hopper; a high-temperature flue gas evaporation drying tower connected to the top of the first dust collector; a high-salt wastewater atomization device arranged inside the first dust collector; a second bin pump installed at the bottom of the high-temperature flue gas evaporation drying tower; an ash conveying pipeline connecting the first bin pump and the second bin pump; a second dust collector communicating with the high-temperature flue gas evaporation drying tower. Although the above system improves the operation stability, it needs to add a first dust collector and a second dust collector, which not only has a complex structure and a large floor area, but also increases the system energy consumption; in addition, the above system cannot solve the adverse effects caused by the unstable temperature of the high-temperature flue gas, and thus cannot ensure the evaporation and drying effect of the wastewater.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a wastewater drying effect detection system and method, which can quickly detect the moisture content of flue gas ash, accurately judge the evaporation and drying effect of wastewater, and then timely adjust the operation parameters of the system, which is beneficial to reducing the system energy consumption and ensuring the stable operation of the system.

[0006] The present invention provides a wastewater drying effect detection system, which includes a drying tower. An atomizer is provided at the top of the drying tower. The atomizer is communicated with a wastewater pipeline. A wastewater regulating valve is provided on the wastewater pipeline. An inlet flue and an outlet flue are respectively provided in the upper and lower parts of the drying tower. A flue gas regulating valve is provided on the inlet flue. Detection devices are respectively connected in parallel on the inlet flue and the outlet flue. The detection device includes a smoke inlet pipe, a smoke transmission pipe and an ash transmission pipe. A valve and a filter are successively provided on the smoke inlet pipe. The flue gas outlet and the ash outlet of the filter are respectively communicated with the smoke transmission pipe and the ash transmission pipe. A fan is provided on the smoke transmission pipe. An ash accumulator is provided at the outlet end of the ash transmission pipe. A weight sensor for detecting the ash mass in the ash accumulator is provided at the bottom of the ash accumulator. A dust discharge pipeline is provided at the bottom of the drying tower.

[0007] The wastewater drying effect detection system of the present invention further includes a controller. The controller is provided with a calculation module. The controller is respectively electrically connected to the wastewater regulating valve, the flue gas regulating valve, the valve and the fan. The calculation module is electrically connected to the weight sensor. The calculation module calculates the ash moisture content X through the following formula:

[0008] X = (m B - m A ) / m B

[0009] Where: m B is the detection result of the ash mass of the weight sensor on the outlet flue; m A is the detection result of the ash mass of the weight sensor on the inlet flue. m A , m B are the detection results of the ash mass at the same time.

[0010] Further, the controller adjusts the gas-liquid ratio of the drying tower according to the ash moisture content X fed back by the calculation module; it can be understood that the following adjustments to the gas-liquid ratio of the drying tower are all adjusted based on the preset gas-liquid ratio:

[0011] If X ≤ 1.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to reduce the gas-liquid ratio by 5 - 10%;

[0012] If 1.0% < X ≤ 2.0%, the controller does not adjust the flue gas regulating valve and the wastewater regulating valve to maintain the preset gas-liquid ratio;

[0013] If 2.0% < X ≤ 3.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 5 - 15%;

[0014] If 3.0% < X ≤ 5.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 20 - 30%;

[0015] If X > 5.0%, the controller closes the flue gas regulating valve and the waste water regulating valve to stop the operation of the drying tower.

[0016] Furthermore, the atomizer can be a centrifugal atomizer, a multi-fluid atomizer, etc.; the atomizer can atomize the waste water into droplets with an average particle size of 40 - 80 μm.

[0017] Furthermore, the aperture of the filter is 10 - 20 μm.

[0018] Furthermore, the inlet of the flue gas pipe is installed in the direction of the flue gas coming, and the outlet of the flue gas pipe is installed in the direction of the flue gas going, and the distance between the two is more than 0.5 m. A reducer is provided between the flue gas pipe and the ash conveying pipe, and the reducer and the ash conveying pipe are arranged vertically downward; the diameter of the ash conveying pipe is 1 / 5 to 1 / 3 of the diameter of the flue gas pipe.

[0019] Furthermore, the ash accumulator has a rated volume, and the rated volume is 0.5 - 1.0 L; the weight sensor detects the mass of the ash in the ash accumulator when the ash in the ash accumulator reaches the rated volume. More specifically, an ash inlet and an ash outlet are respectively provided at the top and bottom of the ash accumulator. In the ash accumulation state, the ash inlet is open and the ash outlet is closed; when the ash in the ash accumulator reaches the rated volume, the ash inlet is closed and the ash outlet is open, and all the ash in the ash accumulator falls onto the weight sensor below it for weighing.

[0020] The present invention also provides a method for detecting the drying effect of waste water, which uses the above-mentioned waste water drying effect detection system to evaporate and dry the waste water with high-temperature flue gas.

[0021] Specifically, the temperature of the high-temperature flue gas (i.e., the flue gas in the inlet flue) should be 300 - 400 °C; the drying tower first operates at a preset gas-liquid ratio, and the preset gas-liquid ratio of the drying tower is set as follows according to the temperature T of the high-temperature flue gas:

[0022] If 300 °C ≤ T ≤ 320 °C, set the preset gas-liquid ratio to 15000 - 16000 Nm 3 / m 3 ;

[0023] If 320 °C < T ≤ 340 °C, set the preset gas-liquid ratio to 13000 - 14000 Nm 3 / m 3 ;

[0024] If 340 °C < T ≤ 360 °C, set the preset gas-liquid ratio to 11500 - 12500 Nm 3 / m 3 ;

[0025] If 360 °C < T ≤ 380 °C, set the preset gas-liquid ratio to 10500 - 11000 Nm 3 / m3 ;

[0026] If 380°C < T ≤ 400°C, set the preset gas-liquid ratio to 9500 - 10000 Nm 3 / m 3 .

[0027] During operation, the controller adjusts the gas-liquid ratio of the drying tower according to the ash moisture content X fed back by the calculation module as follows:

[0028] If X ≤ 1.0%, reduce the gas-liquid ratio by 5 - 10% relative to the preset gas-liquid ratio; if 1.0% < X ≤ 2.0%, maintain the preset gas-liquid ratio unchanged; if 2.0% < X ≤ 3.0%, increase the gas-liquid ratio by 5 - 15% relative to the preset gas-liquid ratio; if 3.0% < X ≤ 5.0%, increase the gas-liquid ratio by 20 - 30% relative to the preset gas-liquid ratio; if X > 5.0%, stop the operation of the drying tower.

[0029] The implementation of the present invention has at least the following advantages:

[0030] 1. By respectively arranging specific detection devices on the inlet flue and the outlet flue, the present invention can quickly detect the ash moisture content of the outlet flue gas during the operation of the system, thus eliminating the need for the conventional sampling and detection method of drying for several hours after sampling. The rapid detection of the wastewater evaporation effect can be achieved within a few minutes, greatly shortening the detection time.

[0031] 2. By directly detecting the ash moisture content of the flue gas at the outlet of the system, the present invention can accurately reflect the wastewater evaporation and drying effect of the system, avoiding the uncertainty caused by indirectly reflecting the wastewater evaporation effect through the flue gas temperature in the conventional method, improving the accuracy of the detection results, and reducing the operation risk of the system.

[0032] 3. The present invention can directly and accurately detect the wastewater evaporation and drying effect of the system, and then timely and accurately adjust the operation parameters of the system. It can well overcome the adverse effects brought by the temperature fluctuation of the high-temperature flue gas, which is beneficial to reducing the system energy consumption, preventing problems such as wet ash and blockage, and ensuring the continuous and stable operation of the system.

[0033] 4. The present invention can ensure the evaporation and drying effect of the wastewater, effectively preventing problems such as agglomeration or caking caused by high ash moisture at the outlet of the drying tower, which seriously affects the resource utilization of fly ash (i.e., ash) and the normal operation of the downstream flue gas dust removal system, and at the same time minimizing the system energy consumption.

[0034] 5. The present invention can stably maintain the ash moisture content of the system within 2%, effectively avoiding the adverse problem of corrosion of flue ducts, valves, etc. caused by excessive moisture in the ash absorbing and dissolving SO2, SO3, HCl, etc. in the flue gas, and improving the operating stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of a waste water drying effect detection system according to an embodiment;

[0037] Figure 2 It is a schematic structural diagram of a detection device according to an embodiment.

[0038] Description of the reference numerals in the drawings:

[0039] 1: Drying tower; 2: Atomizer; 3: Waste water pipeline; 31: Waste water regulating valve; 4: Inlet flue duct; 41: Flue gas regulating valve; 5: Outlet flue duct; 6: First detection device; 7: Second detection device; 8: Ash discharge pipeline; 9: Smoke inlet pipe; 10: Valve; 11: Filter; 12: Smoke transmission pipe; 13: Ash transmission pipe; 14: Fan; 15: Ash accumulator; 16: Weight sensor; 17: Reducing pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0041] It should be noted that the terms used herein are only for describing the specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless otherwise clearly specified in the context, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] Embodiment 1

[0044] As Figure 1 shown, the wastewater drying effect detection system of this embodiment includes a drying tower 1. An atomizer 2 is provided at the top of the drying tower 1. The atomizer 2 is communicated with a wastewater pipeline 3. A wastewater regulating valve 31 is provided on the wastewater pipeline 3. An inlet flue 4 and an outlet flue 5 for high-temperature flue gas to enter and exit are respectively provided in the upper and lower parts of the drying tower 1. A flue gas regulating valve 41 is provided on the inlet flue 4. A first detection device 6 and a second detection device 7 are respectively provided in parallel on the inlet flue 4 and the outlet flue 5. An ash discharge pipeline 8 is provided at the bottom of the drying tower 1.

[0045] The structures of the first detection device 6 and the second detection device 7 are the same (collectively referred to as the detection device); as Figure 2 shown, the detection device includes a smoke inlet pipe 9. A valve 10 is provided at the inlet end of the smoke inlet pipe 9. A filter 11 is provided at the outlet end of the smoke inlet pipe 9. The smoke outlet and the ash outlet of the filter 11 are respectively communicated with a smoke transmission pipe 12 and an ash transmission pipe 13. A fan 14 is provided on the smoke transmission pipe 12. An ash accumulator 15 is provided at the outlet end of the ash transmission pipe 13. A weight sensor 16 for detecting the ash mass in the ash accumulator 15 is provided at the bottom of the ash accumulator 15.

[0046] The drying tower 1 is mainly used to evaporate and dry the wastewater by using the heat of the high-temperature flue gas; there is no strict limit on the size of the drying tower 1, and it can be reasonably set according to actual needs. In this embodiment, the height-diameter ratio of the drying tower 1 can be 1 / 10 to 1 / 2, the diameter of the drying tower 1 can be 1.5 - 10 m, and the height of the drying tower 1 can be 12 - 25 m.

[0047] An atomizer 2 is provided at the top of the drying tower 1. The atomizer 2 is mainly used to atomize the wastewater into droplets with an average particle size of 40 - 80 μm. There is no strict limit on the type of the atomizer 2. For example, a centrifugal atomizer, a multi-fluid atomizer, etc. can be used. The atomizer 2 is communicated with the wastewater pipeline 3. A wastewater regulating valve 31 is provided on the wastewater pipeline 3. The wastewater regulating valve 31 is used to adjust the wastewater flow rate.

[0048] A flue gas regulating valve 41 is provided on the inlet flue 4, and the flue gas regulating valve 41 is used to regulate the flue gas flow rate. A first detection device 6 is arranged in parallel on the inlet flue 4, and a second detection device 7 is arranged in parallel on the outlet flue 5. The first detection device 6 and the second detection device 7 are respectively used for sampling and weighing the ash in the flue gas in the inlet flue 4 and the outlet flue 5. The high-temperature flue gas from the thermal power plant enters the drying tower 1 from the inlet flue 4, and the temperature of the high-temperature flue gas is preferably 300 - 400 °C; at the same time, the waste water is atomized into droplets by the atomizer 2, and the high-temperature flue gas and the droplets formed by the atomization of the waste water are in full contact and heat exchange inside the drying tower 1. The heat of the high-temperature flue gas evaporates and dries the waste water droplets, and the waste water droplets are dried into solid particles (i.e., ash / fly ash), and a part of the ash mixed in the flue gas is discharged through the outlet flue 5, and the rest of the ash is discharged through the ash discharge pipe 8.

[0049] The detection device includes a smoke inlet pipe 9, and a valve 10 is provided on the smoke inlet pipe 9. The valve 10 is mainly used to control whether the high-temperature flue gas enters the smoke inlet pipe 9 and regulate the flow rate of the high-temperature flue gas entering the smoke inlet pipe 9. A filter 11 is provided at the outlet end of the smoke inlet pipe 9. The filter 11 is mainly used to intercept the ash in the high-temperature flue gas, and the aperture of the filter 11 can be 10 - 20 μm.

[0050] The flue gas outlet and the ash outlet of the filter 11 are respectively communicated with the smoke transmission pipe 12 and the ash transmission pipe 13. The flue gas filtered by the filter 11 returns to the inlet flue 4 through the smoke transmission pipe 12. A fan 14 is provided in the smoke transmission pipe 12. The fan 14 is mainly used to provide the conveying power for the high-temperature flue gas, so that the high-temperature flue gas flows from the smoke inlet pipe 9 through the filter 11 to the smoke transmission pipe 12. In addition, the fan 14 can also regulate the flow rate of the flue gas in the smoke transmission pipe 12.

[0051] The ash intercepted by the filter 11 enters the ash transmission pipe 13. A reducing pipe 17 is provided between the smoke inlet pipe 9 and the ash transmission pipe 13. The reducing pipe 17 and the ash transmission pipe 13 are arranged vertically downward, and the reducing pipe 17 gradually reduces in diameter from the smoke inlet pipe 9 to the ash transmission pipe 13. The reducing pipe 17 can make the ash more compact. The diameter of the ash transmission pipe 13 can be 1 / 5 to 1 / 3 of the diameter of the smoke inlet pipe 9. The diameter of the smoke inlet pipe 9 can be 0.1 - 0.2 m. The outlet end of the ash transmission pipe 13 is connected to the upper end of the ash accumulator 15. Heat insulation materials can be provided on the outside of the smoke inlet pipe 9, the reducing pipe 17, and the ash accumulator 15 to prevent the condensation of high-temperature flue gas and the dampness of ash.

[0052] Open the valve 10 and the fan 14 of the first detection device 6, and a part of the high-temperature flue gas in the inlet flue 4 enters the smoke inlet pipe 9 of the first detection device 6; after being filtered by the filter 11, the flue gas returns to the inlet flue 4 through the smoke transmission pipe 12, and the ash intercepted by the filter 11 vertically enters the reducing pipe 17 and enters the ash accumulator 15 after being compacted by the reducing pipe 17.

[0053] Open the valve 10 and the fan 14 of the second detection device 7. Part of the flue gas in the outlet flue 5 enters the smoke inlet pipe 9 of the second detection device 7. After being filtered by the filter 11, the flue gas returns to the outlet flue 5 through the smoke transmission pipe 12. The ash intercepted by the filter 11 vertically descends into the reducer pipe 17 and enters the ash accumulator 15 after being compacted by the reducer pipe 17.

[0054] The ash accumulators 15 in the first detection device 6 and the second detection device 7 are mainly used to collect the ash in the flue gas. The ash accumulator 15 has a rated volume, for example, 0.5 - 1.0 L. The top and bottom of the ash accumulator 15 are respectively provided with an ash inlet and an ash outlet; in the ash accumulation state, the ash inlet is open and the ash outlet is closed; when the ash in the ash accumulator 15 reaches the rated volume, the ash inlet is closed and the ash outlet is opened. At this time, all the ash in the ash accumulator 15 falls onto the weight sensor 16 below it for weighing.

[0055] It can be understood that in the initial state, the ash inlet of the ash accumulator 15 is open and the ash outlet is closed at the same time. As the ash in the ash conveying pipe 13 continuously falls into the ash accumulator 15, when the ash volume in the ash accumulator 15 reaches the rated volume, the ash inlet is closed and the ash no longer enters the ash accumulator 15; at the same time, a weight sensor 16 is provided below the ash accumulator 15. When the ash volume in the ash accumulator 15 reaches the rated volume, the ash outlet is opened and all the ash in the ash accumulator 15 falls onto the weight sensor 16 below it for weighing. After weighing, the ash outlet is closed, the ash inlet is opened and ash accumulation is carried out again; at the same time, the cleaning mechanism is used to clean the ash on the weight sensor 16 so as to wait for the next weighing. The cleaned ash is sent to the ash discharge pipe 8 through the collection pipe.

[0056] The wastewater drying effect detection system of this embodiment further includes a controller. The controller is provided with a calculation module. The controller is electrically connected to the wastewater regulating valve 31, the flue gas regulating valve 41, the valve 10 and the fan 14 to adjust the flow rates of the flue gas and the wastewater, and further control the gas-liquid ratio (i.e., the ratio of the flue gas volume to the wastewater volume); at the same time, the calculation module is electrically connected to the weight sensors 16 of the first detection device 6 and the second detection device 7. The weight sensor 16 transmits the ash mass detection result to the calculation module, and the calculation module calculates the ash moisture content X through the following formula:

[0057] X = (m B - m A ) / m B

[0058] Where: m B is the ash mass detection result of the weight sensor 16 on the outlet flue 5; m A is the ash mass detection result of the weight sensor 16 on the inlet flue 4.

[0059] Based on the flue gas temperature T in the inlet flue 4, the controller sets the preset gas-liquid ratio of the drying tower 1 in the following manner:

[0060] If 300°C ≤ T ≤ 320°C, set the preset gas-liquid ratio to 15000 - 16000 Nm 3 / m 3 , for example, 15500 Nm 3 / m 3 ;

[0061] If 320°C < T ≤ 340°C, set the preset gas-liquid ratio to 13000 - 14000 Nm 3 / m 3 , for example, 13500 Nm 3 / m 3 ;

[0062] If 340°C < T ≤ 360°C, set the preset gas-liquid ratio to 11500 - 12500 Nm 3 / m 3 , for example, 12000 Nm 3 / m 3 ;

[0063] If 360°C < T ≤ 380°C, set the preset gas-liquid ratio to 10500 - 11000 Nm 3 / m 3 , for example, 11000 Nm 3 / m 3 ;

[0064] If 380°C < T ≤ 400°C, set the preset gas-liquid ratio to 9500 - 10000 Nm 3 / m 3 , for example, 10000 Nm 3 / m 3 .

[0065] The drying tower first operates at the preset gas-liquid ratio; during operation, the controller adjusts the gas-liquid ratio of the drying tower according to the ash moisture content X fed back by the calculation module as follows:

[0066] If X ≤ 1.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to reduce the gas-liquid ratio by 5 - 10%; X ≤ 1.0% indicates that the wastewater evaporation effect of the system is good, but there is a problem of excessive heat consumption. By reducing the gas-liquid ratio of the system by 5 - 10%, the energy consumption of the system can be reduced by 5 - 10%.

[0067] If 1.0% < X ≤ 2.0%, the controller does not adjust the flue gas regulating valve and the wastewater regulating valve to maintain the preset gas-liquid ratio; 1.0% < X ≤ 2.0% indicates that the wastewater evaporation effect of the system is good. At this time, the ash moisture content meets the industry standard requirements, and there is no need to adjust the operating parameters of the system.

[0068] If 2.0% < X ≤ 3.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 5 - 15%; 2.0% < X ≤ 3.0% indicates that the wastewater evaporation effect of the system is poor. At this time, the ash moisture content is higher than the industry standard requirements, but the ash fluidity is still good. By increasing the gas-liquid ratio of the system by 5 - 15%, the drying capacity of the system can be improved.

[0069] If 3.0% < X ≤ 5.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 20 - 30%; 3.0% < X ≤ 5.0% indicates that the wastewater evaporation effect of the system is bad. At this time, the ash moisture content is higher than the industry standard requirements, but the ash fluidity is still acceptable. By increasing the gas-liquid ratio of the system by 20 - 30%, the drying capacity of the system can be improved.

[0070] If X > 5.0%, the controller closes the flue gas regulating valve and the wastewater regulating valve to stop the operation of the drying tower; X > 5.0% indicates that the wastewater evaporation effect of the system is extremely poor, and there are risks such as wet ash, blockage, and corrosion. At this time, it is recommended to stop the operation of the system.

[0071] During the operation of the system in this embodiment, the moisture content of the flue gas ash can be quickly detected, so there is no need for hours of drying treatment after sampling, greatly shortening the detection time. The single detection time is about 2 - 6 minutes, realizing the rapid detection of the wastewater evaporation effect. At the same time, by directly detecting the moisture content of the flue gas ash in the outlet flue, it can accurately reflect the wastewater evaporation and drying effect of the system, avoiding the uncertainty brought by indirectly judging the wastewater evaporation effect through the flue gas temperature, and reducing the operation risk of the system. By quickly and accurately detecting the moisture content of the flue gas ash, it can accurately judge the wastewater evaporation and drying effect of the system, and then timely and accurately adjust the operating parameters of the system, well overcoming the adverse effects brought by the temperature fluctuation of the high-temperature flue gas, reducing the system energy consumption while ensuring the wastewater evaporation and drying effect, and improving the operation stability of the system.

[0072] Embodiment 2

[0073] The method for detecting the wastewater drying effect in this embodiment is carried out by using the wastewater drying effect detection system of Embodiment 1, specifically as follows:

[0074] Step 1: Before the system runs, set the preset gas-liquid ratio of the drying tower 1 according to the flue gas temperature T in the inlet flue 4: If 300°C ≤ T ≤ 320°C, set the preset gas-liquid ratio to 15500 Nm 3 / m 3 ; if 320°C < T ≤ 340°C, set the preset gas-liquid ratio to 13500 Nm 3 / m 3 ; if 340°C < T ≤ 360°C, set the preset gas-liquid ratio to 12000 Nm 3 / m 3 ; if 360°C < T ≤ 380°C, set the preset gas-liquid ratio to 11000 Nm 3 / m 3 ; if 380°C < T ≤ 400°C, set the preset gas-liquid ratio to 10000 Nm 3 / m 3 .

[0075] Step 2: The high-temperature flue gas in the inlet flue 4 enters the drying tower 1. At the same time, the wastewater is sent to the atomizer 2 through the wastewater pipeline 3. The atomizer 2 atomizes the wastewater into droplets with an average particle size of 40 - 80 μm. The high-temperature flue gas and the droplets formed by the atomization of the wastewater come into full contact and exchange heat inside the drying tower 1. The heat of the high-temperature flue gas evaporates and dries the wastewater droplets. The wastewater droplets are dried into solid particulate matter (i.e., ash), and a part of the ash mixed in the flue gas is discharged through the outlet flue 5, and the rest of the ash is discharged through the ash discharge pipeline 8.

[0076] Step 3: When the system is running, start the valves 10 and the fan 14 of the first detection device 6 and the second detection device 7 at the same time; the fan 14 provides power for the high-temperature flue gas. The temperature of the high-temperature flue gas at the inlet of the first detection device 6 should be 300 - 400°C. The high-temperature flue gas enters the smoke inlet pipe 9 of the first detection device 6 through the inlet flue 4. The flue gas filtered by the filter 11 flows through the smoke transmission pipe 12 to the inlet flue 4. The ash intercepted by the filter 11 vertically enters the reducer pipe 17, and the ash passes through the reducer pipe 17 and the ash transmission pipe 13 into the ash accumulator 15. When the ash in the ash accumulator 15 accumulates to reach the rated volume, the ash inlet is closed and the ash outlet is opened. All the ash in the ash accumulator 15 falls to the weight sensor 16 below it for weighing. The detection result of the first detection device 6 is recorded as m A .

[0077] Step 4: Part of the flue gas in the outlet flue 5 enters the smoke inlet pipe 9 of the second detection device 7. The flue gas filtered by the filter 11 flows through the smoke transmission pipe 12 to the outlet flue 5. The ash intercepted by the filter 11 vertically descends into the reduced-diameter pipe 17, and the ash passes through the reduced-diameter pipe 17 and the ash transmission pipe 13 and enters the ash accumulator 15. When the ash in the ash accumulator 15 accumulates to reach the rated volume, the ash inlet is closed and the ash outlet is opened. All the ash in the ash accumulator 15 falls onto the weight sensor 16 below it for weighing, and the detection result of the second detection device 7 is recorded as m B 。

[0078] Step 5: The first detection device 6 and the second detection device 7 transmit the detection results to the calculation module of the controller. The calculation module calculates the ash moisture content X through the following formula:

[0079] X = (m B - m A ) / m B

[0080] where: m B is the detection result of the ash accumulation mass of the weight sensor 16 on the outlet flue 5; m A is the detection result of the ash accumulation mass of the weight sensor 16 on the inlet flue 4.

[0081] Step 6: During the operation of the system, the controller adjusts the gas-liquid ratio of the drying tower 1 according to the ash moisture content X fed back by the calculation module as follows:

[0082] If X ≤ 1.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to reduce the gas-liquid ratio by 5 - 10%;

[0083] If 1.0% < X ≤ 2.0%, the controller does not adjust the flue gas regulating valve and the wastewater regulating valve to maintain the preset gas-liquid ratio;

[0084] If 2.0% < X ≤ 3.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 5 - 15%;

[0085] If 3.0% < X ≤ 5.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 20 - 30%;

[0086] If X > 5.0%, the controller closes the flue gas regulating valve and the wastewater regulating valve to stop the operation of the drying tower.

[0087] In the wastewater drying effect detection method of this embodiment, the single detection time of the first detection device 6 and the second detection device 7 is about 2 - 6 min.

[0088] Embodiment 3

[0089] The wastewater drying effect detection method of this embodiment is carried out by the method of Embodiment 2; among them, the diameter of the drying tower 1 is 8 m and the height is 16 m; the atomizer 2 adopts a centrifugal atomizer, and the average particle size of the droplets formed by atomizing the wastewater is about 60 μm; the aperture of the filter 11 is 10 μm, the volume of the dust accumulator 15 is 1 L, the diameter of the flue gas inlet pipe 9 is 0.18 m, and the diameter of the ash conveying pipe 13 is 1 / 4 of the diameter of the flue gas inlet pipe 9; the temperature of the flue gas in the inlet flue 4 is 300 °C, and the controller pre-sets the preset gas-liquid ratio of the drying tower 1 to be 15500 Nm 3 / m 3 。

[0090] After the drying tower 1 starts to operate, the controller adjusts the gas-liquid ratio of the drying tower 1 according to the ash moisture content X fed back by the calculation module as follows: if X ≤ 1.0%, reduce the gas-liquid ratio by 5%; if 1.0% < X ≤ 2.0%, maintain the preset gas-liquid ratio unchanged; if 2.0% < X ≤ 3.0%, increase the gas-liquid ratio by 5%; if 3.0% < X ≤ 5.0%, increase the gas-liquid ratio by 20%; if X > 5.0%, the drying tower 1 stops operating.

[0091] The ash moisture content X of the system every 10 days of operation, as well as the average energy consumption and operation effect during the system operation, are shown in Table 1; among them: the average energy consumption refers to the energy that needs to be additionally supplemented to the thermal power unit due to the evaporation and drying of the wastewater, which is the average value during the test period.

[0092] Embodiment 4

[0093] The wastewater drying effect detection method of this embodiment is basically the same as that of Embodiment 3 except that the flue gas temperature, the preset gas-liquid ratio, and the adjustment method of the gas-liquid ratio by the controller are different.

[0094] In this embodiment, the temperature of the flue gas in the inlet flue 4 is 350 °C, and the controller pre-sets the preset gas-liquid ratio of the drying tower 1 to be 12000 Nm 3 / m 3 ;After the drying tower 1 starts to operate, the controller adjusts the gas-liquid ratio of the drying tower 1 according to the ash moisture content X fed back by the calculation module as follows: if X ≤ 1.0%, reduce the gas-liquid ratio by 10%; if 1.0% < X ≤ 2.0%, maintain the preset gas-liquid ratio unchanged; if 2.0% < X ≤ 3.0%, increase the gas-liquid ratio by 15%; if 3.0% < X ≤ 5.0%, increase the gas-liquid ratio by 30%; if X > 5.0%, the drying tower 1 stops operating.

[0095] The ash moisture content X of the system every 10 days of operation, as well as the average energy consumption and operation effect during the system operation, are shown in Table 2.

[0096] Embodiment 5

[0097] The method for detecting the drying effect of the wastewater in this embodiment is basically the same as that of Embodiment 3, except that the flue gas temperature, the preset gas-liquid ratio, and the adjustment method of the gas-liquid ratio by the controller are different.

[0098] In this embodiment, the temperature of the flue gas in the inlet flue 4 is 400 °C, and the controller preset the preset gas-liquid ratio of the drying tower 1 to be 10,000 Nm 3 / m 3 ; after the drying tower 1 starts to operate, the controller adjusts the gas-liquid ratio of the drying tower 1 according to the ash moisture content X fed back by the calculation module as follows: if X ≤ 1.0%, reduce the gas-liquid ratio by 10%; if 1.0% < X ≤ 2.0%, keep the preset gas-liquid ratio unchanged; if 2.0% < X ≤ 3.0%, increase the gas-liquid ratio by 10%; if 3.0% < X ≤ 5.0%, increase the gas-liquid ratio by 25%; if X > 5.0%, stop the operation of the drying tower 1.

[0099] The ash moisture content X every 10 days of system operation, as well as the average energy consumption and operation effect during system operation, are shown in Table 3.

[0100] Control Example 1

[0101] Except for not setting the first detection device and the second detection device, and not using the controller to adjust the gas-liquid ratio of the drying tower, but fixedly setting the preset gas-liquid ratio of the drying tower to 15,500 Nm 3 / m 3 otherwise, it is basically the same as Embodiment 3.

[0102] Every 10 days of system operation, the sampling detection method is used to detect and calculate the ash moisture content X, and the results are shown in Table 1; at the same time, the average energy consumption and operation effect during system operation are shown in Table 1.

[0103] Table 1 Ash moisture content, average energy consumption and operation effect of Embodiment 3 and Control Example 1

[0104]

[0105] Control Example 2

[0106] Except for not using the controller to adjust the gas-liquid ratio of the drying tower, but fixedly setting the preset gas-liquid ratio of the drying tower to 12,000 Nm 3 / m 3 otherwise, it is basically the same as Embodiment 4.

[0107] The ash moisture content X every 10 days of system operation, as well as the average energy consumption and operation effect during system operation, are shown in Table 2.

[0108] Table 2 Ash moisture content, average energy consumption and operation effect of Embodiment 4 and Control Example 2

[0109]

[0110] Comparative Example 3

[0111] Except that the controller is not used to adjust the gas-liquid ratio of the drying tower, and the preset gas-liquid ratio of the drying tower is fixedly set to 10,000 Nm 3 / m 3 otherwise, it is basically the same as Example 5.

[0112] The ash moisture content X of the system every 10 days of operation, as well as the average energy consumption and operation effect during the system operation, are shown in Table 3.

[0113] Comparative Example 4

[0114] Except that the adjustment method of the controller for the gas-liquid ratio of the drying tower is different, otherwise, it is basically the same as Example 5.

[0115] The adjustment method of the controller for the gas-liquid ratio of the drying tower in this comparative example is as follows: after the drying tower starts to operate, the controller adjusts the gas-liquid ratio of the drying tower according to the ash moisture content X fed back by the calculation module as follows: if X ≤ 2.0%, the preset gas-liquid ratio remains unchanged; if 2.0% < X ≤ 3.0%, the gas-liquid ratio is increased by 3%; if 3.0% < X ≤ 5.0%, the gas-liquid ratio is increased by 15%; if X > 5.0%, the drying tower stops operating.

[0116] The ash moisture content X of the system every 10 days of operation, as well as the average energy consumption and operation effect during the system operation, are shown in Table 3.

[0117] Comparative Example 5

[0118] Except that the adjustment method of the controller for the gas-liquid ratio of the drying tower is different, otherwise, it is basically the same as Example 5.

[0119] The adjustment method of the controller for the gas-liquid ratio of the drying tower in this comparative example is as follows: after the drying tower starts to operate, the controller adjusts the gas-liquid ratio of the drying tower according to the ash moisture content X fed back by the calculation module as follows: if X ≤ 2.0%, the preset gas-liquid ratio remains unchanged; if 2.0% < X ≤ 3.0%, the gas-liquid ratio is increased by 20%; if 3.0% < X ≤ 5.0%, the gas-liquid ratio is increased by 35%; if X > 5.0%, the drying tower stops operating.

[0120] The ash moisture content X of the system every 10 days of operation, as well as the average energy consumption and operation effect during the system operation, are shown in Table 3.

[0121] Table 3 Ash moisture content, average energy consumption and operation effect of Example 5 and Comparative Examples 3 - 5

[0122]

[0123]

[0124] The above results show that:

[0125] 1. In Comparative Example 1, the artificial sampling and detection time is as high as 2 - 3 hours, which is time-consuming and laborious, and cannot quickly reflect the evaporation effect of wastewater. In particular, when the ash moisture content X ≤ 1.0%, the system fails to timely adjust the gas-liquid ratio of the drying tower, resulting in waste of thermal energy and a significant increase in system energy consumption; when the ash moisture content X > 2%, the system fails to timely adjust the gas-liquid ratio of the drying tower, leading to poor drying effect of the wastewater, thus causing problems such as wet ash and blockage, and affecting the quality of fly ash and its subsequent resource utilization.

[0126] 2. In Comparative Example 2 and Comparative Example 3, the gas-liquid ratio of the drying tower was not adjusted according to the ash moisture content X, resulting in extremely unstable drying effect of the wastewater and being unable to well cope with the adverse effects brought by the temperature fluctuation of high-temperature flue gas. In multiple detection results, when the ash moisture content X > 2.0%, it led to an increase in ash moisture, a decrease in fluidity, and problems such as wet ash, blockage, and corrosion, having a serious adverse impact on the normal operation of the system; in addition, some ash agglomerated and caked, resulting in a decline in the quality of fly ash, thus affecting its subsequent resource utilization.

[0127] 3. In Comparative Example 4, other methods were used to adjust the gas-liquid ratio of the drying tower, and the ash moisture content could not be stably controlled within 2%. In particular, when the ash moisture content X > 2.0% (especially X > 5.0%), it not only could not meet the requirements of industry standards, but also led to problems such as wet ash, blockage, and corrosion, which was not conducive to the stable operation of the wastewater drying system and the downstream flue gas dust removal system, and also seriously affected the quality of fly ash and its subsequent resource utilization.

[0128] 4. In Comparative Example 5, other methods were used to adjust the gas-liquid ratio of the drying tower. Although the ash moisture content X was controlled within 1.0%, it caused a great waste of thermal energy and a significant increase in the operating energy consumption of the system.

[0129] 5. The methods of Examples 3 - 5 can automatically sample, detect, and calculate, so as to quickly obtain the ash moisture content of the flue gas (the detection time is only 2 - 6 minutes), which is conducive to accurately judging the evaporation and drying effect of the wastewater; on this basis, by timely and quickly adjusting the operating parameters of the system in a specific way, the ash moisture content of the system can be stably maintained at 1 - 2%, which can not only meet the requirements of industry standards, but also reduce the system energy consumption, well overcome the adverse effects brought by the temperature fluctuation of high-temperature flue gas, ensure the drying effect of the wastewater and the quality of fly ash, and ensure the safe and stable operation of the wastewater drying system and the downstream flue gas dust removal system.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wastewater drying effect detection system, characterized in that It includes a drying tower and a controller. An atomizer is provided at the top of the drying tower. The atomizer is communicated with a wastewater pipeline. A wastewater regulating valve is provided on the wastewater pipeline. An inlet flue and an outlet flue are respectively provided at the upper and lower parts of the drying tower. A flue gas regulating valve is provided on the inlet flue. Detection devices are respectively connected in parallel on the inlet flue and the outlet flue. The detection devices on the inlet flue and the outlet flue have the same structure. The detection device includes a smoke inlet pipe, a smoke transmission pipe and an ash transmission pipe. A valve and a filter are successively provided on the smoke inlet pipe. The flue gas outlet and the ash outlet of the filter are respectively communicated with the smoke transmission pipe and the ash transmission pipe. A fan is provided on the smoke transmission pipe. An ash accumulator is provided at the outlet end of the ash transmission pipe. A weight sensor for detecting the mass of the ash accumulated in the ash accumulator is provided at the bottom of the ash accumulator. The ash accumulator has a rated volume. The weight sensor detects the mass of the ash accumulated in the ash accumulator when the ash accumulated in the ash accumulator reaches the rated volume. A dust discharge pipeline is provided at the bottom of the drying tower; The controller is provided with a calculation module. The controller is respectively electrically connected to the wastewater regulating valve, the flue gas regulating valve, the valve and the fan. The calculation module is electrically connected to the weight sensor. The calculation module calculates the ash moisture content X through the following formula: X = (m B - m A ) / m B Where: m B is the detection result of the ash accumulation mass of the weight sensor on the outlet flue; m A is the detection result of the ash accumulation mass of the weight sensor on the inlet flue; The controller adjusts the gas-liquid ratio of the drying tower according to the ash moisture content X fed back by the calculation module as follows: If X≤1.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to reduce the gas-liquid ratio by 5-10%; If 1.0%<X≤2.0%, the controller does not adjust the flue gas regulating valve and the wastewater regulating valve to maintain the preset gas-liquid ratio; If 2.0%<X≤3.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 5-15%; If 3.0%<X≤5.0%, the controller adjusts the flue gas regulating valve and / or the wastewater regulating valve to increase the gas-liquid ratio by 20-30%; If X>5.0%, the controller closes the flue gas regulating valve and the wastewater regulating valve to stop the operation of the drying tower.

2. The wastewater drying effect detection system according to claim 1, characterized in that The atomizer is a centrifugal atomizer or a multi-fluid atomizer.

3. The wastewater drying effect detection system according to claim 1, characterized in that The atomizer can atomize the wastewater into mist droplets with an average particle size of 40-80 μm.

4. The wastewater drying effect detection system according to claim 1, characterized in that, The aperture of the filter is 10-20μm.

5. The wastewater drying effect detection system according to claim 1, characterized in that, A reducer pipe is provided between the smoke inlet pipe and the ash transmission pipe. The reducer pipe and the ash transmission pipe are arranged vertically downward.

6. The wastewater drying effect detection system according to claim 1, wherein, The rated volume is 0.5-1.0L.

7. A method for detecting the drying effect of wastewater, characterized in that, Using the wastewater drying effect detection system according to any one of claims 1-6 to evaporate and dry the wastewater with high-temperature flue gas.

8. The wastewater drying effect detection method according to claim 7, characterized in that, The temperature of the high-temperature flue gas is 300-400 ℃; The drying tower first operates at a preset gas-liquid ratio. The preset gas-liquid ratio of the drying tower is set as follows according to the temperature T of the high-temperature flue gas: If 300 °C ≤ T ≤ 320 °C, set the preset gas-liquid ratio to 15000 - 16000 Nm 3 / m 3 ; If 320 °C < T ≤ 340 °C, set the preset gas-liquid ratio to 13000 - 14000 Nm 3 / m 3 ; If 340 °C < T ≤ 360 °C, set the preset gas-liquid ratio to 11500 - 12500 Nm 3 / m 3 ; If 360 °C < T ≤ 380 °C, set the preset gas-liquid ratio to 10500 - 11000 Nm 3 / m 3 ; If 380 °C < T ≤ 400 °C, set the preset gas-liquid ratio to 9500 - 10000 Nm 3 / m 3 .

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