A high-concentration brine evaporation crystallization system and automatic control method thereof

Abstract

The invention discloses a high-concentration salt water evaporation and crystallization system, comprising a raw material box, a first-effect heater, a first-effect separator, a first-effect gas-liquid separator, a second-effect heater, a second-effect separator, a second-effect gas-liquid separator, a cyclone separator, a thickener, a centrifuge, a screw conveyor, a drying bed, a silo and a mother liquor barrel; the invention also discloses an automatic control method for the high-concentration salt water evaporation and crystallization system; the advantages are: the invention realizes automatic adjustment of the system load by automatically detecting various process parameters, balances the water and salt in the system, ensures the continuous and stable operation of the device at high load, and improves the automatic control of the high-concentration salt water evaporation and crystallization system; realizes automatic flushing of the system's easily blocked pipelines, solves the problem that the evaporation system pipeline equipment is frequently blocked and affects the continuous and stable operation of the device; reduces the frequency of blockage of the evaporation and crystallization pipeline, and also greatly reduces the labor intensity of the main control operator, ensuring the continuous and stable operation of the evaporation and crystallization system.

Description

Technical Field

[0001] The invention relates to the technical field of high-concentration salt wastewater treatment, and in particular to a high-concentration salt water evaporation and crystallization system and an automated control method thereof. Background Art

[0002] With the increasing shortage of water resources, zero discharge of industrial wastewater is the inevitable path for enterprises to achieve green and high-quality development, and the evaporation crystallization process is the key to achieving zero discharge of highly concentrated brine. The evaporation crystallization process can separate the salt (mainly sodium chloride and sodium sulfate) in highly concentrated brine in the form of crystalline salt, so as to achieve full circulation of water quality and zero discharge of wastewater.

[0003] At present, in the evaporation and crystallization process, in order to reduce the cost of wastewater treatment, make full use of thermal energy and reduce steam consumption, multi-effect evaporation consisting of multiple evaporation crystallizers is often used. However, during the operation of the existing multi-effect evaporation system, the water balance and salt balance are often destroyed, resulting in the system being unable to operate continuously and stably; in addition, the evaporation system will precipitate solid salts, which will clog pipes and equipment. At present, only the easily clogged equipment and pipes are manually flushed regularly, which will not only increase the labor intensity of personnel, but also increase the system load fluctuation range due to untimely cleaning, resulting in unstable system operation, reduced product quality, and even system shutdown. Summary of the invention

[0004] In order to improve the continuous and stable operation of the evaporation crystallization system, improve product quality, and reduce labor intensity, the first purpose of the present invention is to provide a high-concentration brine evaporation crystallization system, and the second purpose of the present invention is to provide an automated control method for the high-concentration brine evaporation crystallization system.

[0005] The first object of the present invention is implemented by the following technical solutions:

[0006] A high-concentration brine evaporation and crystallization system comprises a raw material box, a first-effect heater, a first-effect separator, a first-effect gas-liquid separator, a second-effect heater, a second-effect separator, a second-effect gas-liquid separator, a cyclone separator, a thickener, a centrifuge, a screw conveyor, a drying bed, a silo and a mother liquid barrel;

[0007] The liquid outlet of the high-concentration brine water pipeline is connected to the liquid inlet of the raw material box, the liquid outlet of the raw material box is connected to the liquid inlet of the feed pump, the liquid outlet of the feed pump is connected to the first-effect circulation pipeline through a pipeline, the liquid outlet of the first-effect circulation pipeline is connected to the liquid inlet of the first-effect circulation pump, the liquid outlet of the first-effect circulation pump is connected to the shell-side inlet of the first-effect heater through a pipeline, the shell-side outlet of the first-effect heater is connected to the inlet of the first-effect separator through a pipeline, the liquid outlet at the bottom of the first-effect separator is connected to the liquid inlet of the first-effect circulation pipeline through a pipeline, the steam outlet at the top of the first-effect separator is connected to the inlet of the first-effect gas-liquid separator through a pipeline, the steam outlet of the first-effect gas-liquid separator is connected to the tube-side inlet of the second-effect heater through a pipeline, and the tube-side outlet of the second-effect heater is connected to the inlet of the second-effect separator through a pipeline;

[0008] The first-effect circulation pipeline is also connected to the second-effect circulation pipeline through a pipeline, the liquid outlet of the second-effect circulation pipeline is connected to the liquid inlet of the second-effect circulation pump, the liquid outlet of the second-effect circulation pump is connected to the liquid inlet of the shell side of the second-effect heater through a pipeline, the liquid outlet of the shell side of the second-effect heater is connected to the inlet of the second-effect separator through a pipeline, and the liquid outlet in the middle of the second-effect separator is connected to the liquid inlet of the second-effect circulation pipeline through a pipeline; the discharge port at the bottom of the second-effect separator is connected to the inlet of the discharge pump through a pipeline, the outlet of the discharge pump is connected to the inlet of the cyclone separator through a discharge pipeline, the discharge port at the bottom of the cyclone separator is connected to the inlet of the thickener through a pipeline, the discharge port of the thickener is connected to the inlet of the centrifuge through a pipeline, the discharge port of the centrifuge is connected to the inlet of the screw conveyor, the outlet of the screw conveyor is connected to the inlet of the drying bed, and the outlet of the drying bed is connected to the inlet of the silo;

[0009] The steam outlet at the top of the second-effect separator is connected to the inlet of the second-effect gas-liquid separator through a pipeline, and the steam outlet of the second-effect gas-liquid separator is connected to the inlet of the secondary steam condensate tank through a pipeline;

[0010] The outlet of the secondary steam condensate tank is connected to the inlet of the condensate pump through a pipeline, and the outlet of the condensate pump is connected to the inlet of the recycling water tank through a pipeline;

[0011] The outlet of the low-pressure steam pipeline is connected to the tube-side inlet of the first-effect heater, and the tube-side outlet of the first-effect heater is connected to the inlet of the recycled water tank through a pipeline.

[0012] Furthermore, the liquid outlet of the cyclone separator, the liquid outlet of the thickener and the liquid outlet of the centrifuge are all connected to the inlet of the mother liquid barrel through a pipeline, the liquid outlet of the mother liquid barrel is connected to the inlet of the mother liquid pump through a pipeline, the outlet of the mother liquid pump is connected to the second-effect circulation pipeline through a pipeline, and a stirrer is provided in the mother liquid barrel.

[0013] Furthermore, a first-effect liquid phase temperature sensor is provided at the bottom of the first-effect separator; a steam flow meter is provided at the outlet of the low-pressure steam pipeline, a steam regulating valve is provided at the pipe inlet of the first-effect heater; and a water inlet flow meter is provided at the liquid outlet of the high-concentration brine water pipeline;

[0014] A first-effect liquid level sensor is provided in the first-effect separator; a feed flow meter and a feed regulating valve are provided along the liquid flow direction on the pipeline connecting the feed pump and the first-effect circulation pipeline;

[0015] A first-effect gas phase temperature sensor and a first-effect pressure sensor are respectively provided at the steam outlet of the first-effect separator; a second-effect liquid level sensor is provided in the second-effect separator; a mother liquid level sensor is provided in the mother liquid barrel; a material transfer regulating valve is provided on the pipeline connecting the first-effect circulation pipeline and the second-effect circulation pipeline; a mother liquid reflux regulating valve is provided on the pipeline connecting the mother liquid pump and the second-effect circulation pipeline;

[0016] A density sensor is provided at the outlet of the discharge pump, and a discharge regulating valve is provided on the discharge pipeline; the discharge pipeline upstream of the discharge regulating valve is also connected to the second-effect separator through a pipeline, and a return regulating valve is provided on the pipeline connecting the discharge pipeline and the second-effect separator;

[0017] A liquid level sensor is provided in the thickener, and a discharge regulating valve is provided on a pipeline connecting the thickener and the centrifuge;

[0018] A condensate level sensor is provided in the secondary steam condensate tank, and a condensate regulating valve is provided at the outlet of the condensate pump;

[0019] The signal output ends of the first-effect liquid phase temperature sensor, the steam flowmeter, the water inlet flowmeter, the first-effect liquid level sensor, the feed flowmeter, the first-effect gas phase temperature sensor, the first-effect pressure sensor, the second-effect liquid level sensor, the mother liquor level sensor, the density sensor, the feed liquid level sensor and the condensate level sensor are all signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the steam regulating valve, the feed regulating valve, the feed regulating valve, the mother liquor reflux regulating valve, the discharge regulating valve, the return material regulating valve, the discharge regulating valve and the condensate regulating valve, respectively.

[0020] Further, it also includes a flushing water tank, the water outlet of the flushing water tank is connected to the inlet of the flushing water pump through a pipeline, the outlet of the flushing water pump is divided into five routes, the first route is connected to the discharge port of the second-effect separator through a first flushing pipeline, the second route is connected to the discharge pipeline upstream of the discharge regulating valve through a second flushing pipeline, the third route is connected to the liquid outlet of the mother liquid barrel through a third flushing pipeline, the fourth route is connected to the discharge port of the thickener through a fourth flushing pipeline, and the fifth route is connected to the inlet of the centrifuge through a fifth flushing pipeline;

[0021] A first flushing valve is provided on the first flushing pipeline, a second flushing valve is provided on the second flushing pipeline, a third flushing valve is provided on the third flushing pipeline, a fourth flushing valve is provided on the fourth flushing pipeline, and a fifth flushing valve is provided on the fifth flushing pipeline.

[0022] The second object of the present invention is implemented by the following technical solutions:

[0023] An automated control method for a high-concentration brine evaporation and crystallization system uses a system load control method to control the high-concentration brine evaporation and crystallization system to ensure water-salt balance in the system; after the high-concentration brine evaporation and crystallization system has been running for a certain period of time, an automatic flushing control method is used to flush the high-concentration brine evaporation and crystallization system to ensure stable operation of the system.

[0024] Furthermore, the system load control method comprises the following steps:

[0025] S11, using a water inlet flow meter to monitor the water flow entering the raw material box, and calculating the average value of the water inlet flow into the raw material box;

[0026] S12, according to the average value of the water inlet flow rate of the raw material box calculated in step S11, using the heat calculation formula, calculate the initial value of the steam flow rate entering the tube side of the first-effect heater, and adjust the initial opening of the steam regulating valve according to the initial value of the steam flow rate;

[0027] S13, using a first-effect gas phase temperature sensor to monitor the liquid phase temperature in the first-effect separator, when the liquid phase temperature in the first-effect separator is less than 70°C, the steam regulating valve is opened wider; when the liquid phase temperature in the first-effect separator is greater than 75°C, the steam regulating valve is opened narrower; when the liquid phase temperature in the first-effect separator is greater than 85°C, the steam regulating valve is closed;

[0028] S14, using a first-effect liquid level sensor to monitor the liquid level in the first-effect separator, and adjusting the opening of the feed regulating valve according to the liquid level in the first-effect separator, so that the liquid level in the first-effect separator is maintained at 55%-60% of the preset liquid level upper limit value;

[0029] S15. Use the second-effect liquid level sensor to monitor the liquid level in the second-effect separator, and adjust the opening of the feed regulating valve and the mother liquid reflux regulating valve according to the liquid level in the second-effect separator. The method is as follows:

[0030] S151, using a mother liquid level sensor to monitor the liquid level in the mother liquid barrel, when the liquid level in the mother liquid barrel is greater than 65% of the maximum liquid level in the mother liquid barrel, start the mother liquid pump; when the liquid level in the mother liquid barrel is less than 40% of the maximum liquid level in the mother liquid barrel, stop the mother liquid pump;

[0031] S152. When the liquid level in the secondary effect separator is less than 60% of the maximum liquid level of the secondary effect separator, increase the opening of the feed regulating valve and the mother liquor reflux regulating valve;

[0032] When 60% of the maximum liquid level of the second-effect separator is ≤ the liquid level in the second-effect separator < 63% of the maximum liquid level of the second-effect separator, reduce the opening of the feed regulating valve;

[0033] When 63% of the maximum liquid level of the second-effect separator is ≤ the liquid level in the second-effect separator < 65% of the maximum liquid level of the second-effect separator, close the feed regulating valve and reduce the opening of the mother liquor reflux regulating valve;

[0034] When the liquid level in the secondary effect separator is ≥ 65% of the maximum liquid level of the secondary effect separator, close the feed regulating valve and the mother liquor reflux regulating valve;

[0035] S16. Use a density sensor to monitor the density of the liquid feed at the outlet of the discharge pump. When it is monitored that the density of the liquid feed at the outlet of the discharge pump reaches a preset density, open the discharge regulating valve and close the return regulating valve; when it is monitored that the density of the liquid feed at the outlet of the discharge pump is lower than the preset density, open the return regulating valve and close the discharge regulating valve.

[0036] Furthermore, the automatic flushing control method is as follows:

[0037] The discharge pump inlet and outlet pipeline anti-blocking method is used to flush the discharge pump feed pipeline and the discharge pump discharge pipeline; the mother liquor pump pipeline anti-blocking method is used to flush the mother liquor pump outlet; the centrifuge feed pipeline anti-blocking method is used to flush the centrifuge feed pipeline.

[0038] Furthermore, the method for preventing the inlet and outlet pipelines of the discharge pump from being blocked is as follows:

[0039] During the operation of the discharge pump, flush the discharge pump inlet pipeline every 3 hours: close the second flushing valve, the third flushing valve, the fourth flushing valve and the fifth flushing valve, start the flushing water pump, open the first flushing valve, start the discharge pump, flush for 1 minute, close the flushing water pump and the first flushing valve, and stop the discharge pump;

[0040] During the operation of the discharge pump, flush the discharge pump outlet pipeline every 2 hours: close the first flushing valve, the third flushing valve, the fourth flushing valve and the fifth flushing valve, start the flushing water pump, open the second flushing valve, start the discharge pump, flush for 1 minute, close the flushing water pump and the second flushing valve, and stop the discharge pump.

[0041] Furthermore, the method for preventing the mother liquid pump pipeline from being blocked is as follows:

[0042] During the operation of the mother liquid pump, flush the mother liquid pump outlet pipeline every 6 hours: close the first flushing valve, the second flushing valve, the fourth flushing valve and the fifth flushing valve, start the flushing water pump, open the third flushing valve, start the mother liquid pump, after flushing for 1 minute, close the flushing water pump and the third flushing valve, and stop the mother liquid pump.

[0043] Furthermore, the centrifuge feed pipeline anti-blocking method is:

[0044] Before the centrifuge is shut down, flush the centrifuge feed pipeline: close the first flushing valve, the second flushing valve, the third flushing valve and the fifth flushing valve, start the flushing water pump, open the fourth flushing valve and the discharge regulating valve, flush for 30 seconds, close the fourth flushing valve and the discharge regulating valve, open the fifth flushing valve, flush for 30 seconds, and close the flushing water pump and the fifth flushing valve.

[0045] Advantages of the present invention:

[0046] The present invention realizes automatic adjustment of system load by automatically detecting various process parameters, balances water and salt in the system, ensures continuous and stable operation of the device under high load, and improves the automatic control of the high-concentration brine crystallization system; realizes automatic flushing of easily blocked pipelines in the system, solves the problem that frequent blockage of pipeline equipment in the evaporation system affects the continuous and stable operation of the device; while ensuring the flushing effect, the flushing process is standardized, which greatly reduces the frequency of blockage of the evaporation crystallization pipeline, and also greatly reduces the labor intensity of the main control operator, eliminates factors such as inconsistent manual timing, inconsistent flushing standards, and interference from external events, and ensures the continuous and stable operation of the evaporation crystallization system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 This is a schematic diagram of system connection in Example 1;

[0049] Figure 2 This is the control principle diagram of Example 1.

[0050] In the figure: high-concentration brine water pipeline 1, raw material box 2, feed pump 3, first-effect circulation pipeline 4, first-effect circulation pump 5, first-effect heater 6, first-effect separator 7, first-effect gas-liquid separator 8, second-effect circulation pipeline 9, second-effect circulation pump 10, second-effect heater 11, second-effect separator 12, second-effect gas-liquid separator 13, discharge pump 14, cyclone separator 15, thickener 16, centrifuge 17, screw conveyor 18, drying bed 19, silo 20, mother liquid barrel 21, mother liquid pump 22, mixer 23, secondary steam condensate tank 24, condensate pump 25, reuse water tank 26, low-pressure steam pipeline 27, flushing water tank 28, flushing water pump 29, first-effect liquid phase temperature sensor 3 0, steam flowmeter 31, water inlet flowmeter 32, first effect liquid level sensor 33, feed flowmeter 34, first effect gas phase temperature sensor 35, first effect pressure sensor 36, second effect liquid level sensor 37, mother liquor level sensor 38, density sensor 39, feed liquid level sensor 40, condensate water level sensor 41, controller 42, steam regulating valve 43, feed regulating valve 44, feed regulating valve 45, mother liquor reflux regulating valve 46, discharge regulating valve 47, return regulating valve 48, discharge regulating valve 49, condensate water regulating valve 50, first flushing valve 51, second flushing valve 52, third flushing valve 53, fourth flushing valve 54, fifth flushing valve 55. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Embodiment 1:

[0053] like Figure 1 , 2 A high-concentration brine evaporation and crystallization system shown includes a raw material box 2, a first-effect heater 6, a first-effect separator 7, a first-effect gas-liquid separator 8, a second-effect heater 11, a second-effect separator 12, a second-effect gas-liquid separator 13, a cyclone separator 15, a thickener 16, a centrifuge 17, a screw conveyor 18, a drying bed 19, a silo 20 and a mother liquid barrel 21;

[0054] The liquid outlet of the high-concentration brine water pipeline 1 is communicated with the liquid inlet of the raw material box 2, the liquid outlet of the raw material box 2 is communicated with the liquid inlet of the feed pump 3, the liquid outlet of the feed pump 3 is communicated with the first-effect circulation pipeline 4 through a pipeline, the liquid outlet of the first-effect circulation pipeline 4 is communicated with the liquid inlet of the first-effect circulation pump 5, the liquid outlet of the first-effect circulation pump 5 is communicated with the shell side inlet of the first-effect heater 6 through a pipeline, the shell side outlet of the first-effect heater 6 is communicated with the inlet of the first-effect separator 7 through a pipeline, the liquid outlet at the bottom of the first-effect separator 7 is communicated with the liquid inlet of the first-effect circulation pipeline 4 through a pipeline, the steam outlet at the top of the first-effect separator 7 is communicated with the inlet of the first-effect gas-liquid separator 8 through a pipeline, the steam outlet of the first-effect gas-liquid separator 8 is communicated with the tube side inlet of the second-effect heater 11 through a pipeline, and the tube side outlet of the second-effect heater 11 is communicated with the inlet of the second-effect separator 12 through a pipeline;

[0055] The first-effect circulation pipeline 4 is also connected to the second-effect circulation pipeline 9 through a pipeline, the liquid outlet of the second-effect circulation pipeline 9 is connected to the liquid inlet of the second-effect circulation pump 10, the liquid outlet of the second-effect circulation pump 10 is connected to the liquid inlet of the shell side of the second-effect heater 11 through a pipeline, the liquid outlet of the shell side of the second-effect heater 11 is connected to the inlet of the second-effect separator 12 through a pipeline, and the liquid outlet in the middle of the second-effect separator 12 is connected to the liquid inlet of the second-effect circulation pipeline 9 through a pipeline; the discharge port at the bottom of the second-effect separator 12 is connected to the liquid inlet of the second-effect circulation pipeline 9 through a pipeline; The pipeline is connected to the inlet of the discharge pump 14, the outlet of the discharge pump 14 is connected to the inlet of the cyclone separator 15 through the discharge pipeline, the discharge port at the bottom of the cyclone separator 15 is connected to the inlet of the thickener 16 through the pipeline, the discharge port of the thickener 16 is connected to the inlet of the centrifuge 17 through the pipeline, the discharge port of the centrifuge 17 is connected to the inlet of the screw conveyor 18, the outlet of the screw conveyor 18 is connected to the inlet of the drying bed 19, and the outlet of the drying bed 19 is connected to the inlet of the silo 20;

[0056] The steam outlet at the top of the second-effect separator 12 is connected to the inlet of the second-effect gas-liquid separator 13 through a pipeline, and the steam outlet of the second-effect gas-liquid separator 13 is connected to the inlet of the secondary steam condensate tank 24 through a pipeline;

[0057] The outlet of the secondary steam condensate tank 24 is connected to the inlet of the condensate pump 25 through a pipeline, and the outlet of the condensate pump 25 is connected to the inlet of the recycling water tank 26 through a pipeline;

[0058] The outlet of the low-pressure steam pipeline 27 is communicated with the tube-side inlet of the first-effect heater 6 , and the tube-side outlet of the first-effect heater 6 is communicated with the inlet of the recycled water tank 26 through a pipeline.

[0059] Furthermore, the liquid outlet of the cyclone separator 15, the liquid outlet of the thickener 16 and the liquid outlet of the centrifuge 17 are all connected to the inlet of the mother liquid barrel 21 through a pipeline, the liquid outlet of the mother liquid barrel 21 is connected to the inlet of the mother liquid pump 22 through a pipeline, the outlet of the mother liquid pump 22 is connected to the second-effect circulation pipeline 9 through a pipeline, and a mixer 23 is provided in the mother liquid barrel 21.

[0060] Furthermore, a first-effect liquid phase temperature sensor 30 is provided at the bottom of the first-effect separator 7; a steam flow meter 31 is provided at the outlet of the low-pressure steam pipeline 27, and a steam regulating valve 43 is provided at the pipe inlet of the first-effect heater 6; and a water inlet flow meter 32 is provided at the liquid outlet of the high-concentration brine water pipeline 1;

[0061] A first-effect liquid level sensor 33 is provided in the first-effect separator 7; a feed flow meter 34 and a feed regulating valve 44 are provided along the liquid flow direction on the pipeline connecting the feed pump 3 and the first-effect circulation pipeline 4;

[0062] A first-effect gas phase temperature sensor 35 and a first-effect pressure sensor 36 are respectively provided at the steam outlet of the first-effect separator 7; a second-effect liquid level sensor 37 is provided in the second-effect separator 12; a mother liquid level sensor 38 is provided in the mother liquid barrel 21; a material transfer regulating valve 45 is provided on the pipeline connecting the first-effect circulation pipeline 4 and the second-effect circulation pipeline 9; a mother liquid reflux regulating valve 46 is provided on the pipeline connecting the mother liquid pump 22 and the second-effect circulation pipeline 9;

[0063] A density sensor 39 is provided at the outlet of the discharge pump 14, and a discharge regulating valve 47 is provided on the discharge pipeline; the discharge pipeline upstream of the discharge regulating valve 47 is also connected to the secondary effect separator 12 through a pipeline, and a return regulating valve 48 is provided on the pipeline connecting the discharge pipeline and the secondary effect separator 12;

[0064] A liquid level sensor 40 is provided in the thickener 16, and a discharge regulating valve 49 is provided on the pipeline connecting the thickener 16 and the centrifuge 17;

[0065] A condensate level sensor 41 is provided in the secondary steam condensate tank 24, and a condensate regulating valve 50 is provided at the outlet of the condensate pump 25;

[0066] The signal output ends of the first-effect liquid phase temperature sensor 30, the steam flowmeter 31, the water inlet flowmeter 32, the first-effect liquid level sensor 33, the feed flowmeter 34, the first-effect gas phase temperature sensor 35, the first-effect pressure sensor 36, the second-effect liquid level sensor 37, the mother liquor level sensor 38, the density sensor 39, the feed liquid level sensor 40 and the condensate level sensor 41 are all signal-connected to the signal input end of the controller 42, and the signal output end of the controller 42 is signal-connected to the signal input end of the steam regulating valve 43, the feed regulating valve 44, the feed regulating valve 45, the mother liquor reflux regulating valve 46, the discharge regulating valve 47, the return material regulating valve 48, the discharge regulating valve 49 and the condensate regulating valve 50 respectively.

[0067] The present embodiment further includes a flushing water tank 28, the outlet of the flushing water tank 28 is connected to the inlet of a flushing water pump 29 through a pipeline, and the outlet of the flushing water pump 29 is divided into five routes, the first route is connected to the discharge port of the second-effect separator 12 through a first flushing pipeline, the second route is connected to the discharge pipeline upstream of the discharge regulating valve 47 through a second flushing pipeline, the third route is connected to the liquid outlet of the mother liquid barrel 21 through a third flushing pipeline, the fourth route is connected to the discharge port of the thickener 16 through a fourth flushing pipeline, and the fifth route is connected to the inlet of the centrifuge 17 through a fifth flushing pipeline;

[0068] A first flushing valve 51 is provided on the first flushing line, a second flushing valve 52 is provided on the second flushing line, a third flushing valve 53 is provided on the third flushing line, a fourth flushing valve 54 is provided on the fourth flushing line, and a fifth flushing valve 55 is provided on the fifth flushing line.

[0069] Job Description:

[0070] 1) Materials: The highly concentrated brine in the raw material box 2 is pressurized by the feed pump 3 and transported to the first-effect circulation pipeline 4, and then heated by the first-effect heater 6 and enters the first-effect separator 7 for evaporation. The evaporated raw water is then transported to the first-effect heater 6 by the first-effect circulation pump 5 for heating, and evaporated in the first-effect separator 7. After repeated heating and evaporation, the raw material liquid is passed from the first-effect circulation pipeline 4 to the second-effect circulation pipeline 9 for evaporation again. The evaporated liquid is transported to the second-effect heater 11 by the second-effect circulation pump 10 for heating. The heated liquid is evaporated again in the second-effect separator 12, and the cycle is repeated. When the liquid reaches supersaturation, crystals will precipitate. The precipitated crystals are transported to the cyclone separator 15 by the discharge pump 14 for preliminary separation of solid and liquid. The separated solid phase enters the thickener 16 and is discharged to the centrifuge 17 for secondary separation of solid and liquid. The separated salt is transported to the drying bed 19 by the screw conveyor 18 for drying, and the dried product is packaged by a packaging machine. The mother liquid separated by the centrifuge 17 enters the mother liquid barrel 21 and is transported back to the second-effect circulation pipeline 9 through the mother liquid pump 22 .

[0071] 2) Steam and condensed water: The condensed water in this system is divided into primary steam condensed water and secondary steam condensed water. The primary steam condensed water is the condensed water generated by raw steam. After the raw steam passes through the single-effect heater 6 for heat exchange, the steam condenses into water on the tubes and flows into the reuse water tank 26 by gravity from the outlet pipe of the single-effect heater 6.

[0072] The secondary steam generated in the first-effect separator 7 is used as the heat source of the second-effect heater 11. The secondary steam generated in the second-effect separator 12 flows into the secondary steam condensate tank 24 by gravity after condensation, and then is transported to the recycling water tank 26 through the condensate pump 25. The condensed water generated by the second-effect heater 11 enters the second-effect separator 12.

[0073] 3) Non-condensable gas: There will be non-condensable gas inside the system and in the raw water. If this part of gas is in the first-effect heater 6 and the second-effect heater 11, the heating efficiency of the heater will be reduced, which will cause the evaporation effect of the system to fail to meet the design requirements. Therefore, this part of non-condensable gas needs to be discharged from the system. The non-condensable gas in the first-effect heater 6 and the second-effect heater 11 can be connected to the secondary steam condensate tank 24 and pumped out of the system by a vacuum pump. Figure 1 Not indicated.

[0074] Embodiment 2:

[0075] An automated control method for treating high-concentration brine by using a high-concentration brine evaporation and crystallization system provided in Example 1 is used, and a system load control method is used to control the high-concentration brine evaporation and crystallization system to ensure the water-salt balance in the system; after the high-concentration brine evaporation and crystallization system has been running for a certain period of time, an automatic flushing control method is used to flush the high-concentration brine evaporation and crystallization system to ensure stable operation of the system.

[0076] In this embodiment, the system load control method includes the following steps:

[0077] S11, using the water inlet flow meter 32 to monitor the water flow entering the raw material box 2, and calculating the average value of the water inlet flow of the raw material box 2;

[0078] S12, according to the average value of the water inlet flow rate of the raw material box 2 calculated in step S11, the initial value of the steam flow rate entering the tube side of the first-effect heater 6 is calculated by using the heat calculation formula, and the initial opening of the steam regulating valve 43 is adjusted according to the initial value of the steam flow rate;

[0079] S13, using the first-effect gas phase temperature sensor 35 to monitor the liquid phase temperature in the first-effect separator 7, when the liquid phase temperature in the first-effect separator 7 is less than 70°C, the opening of the steam regulating valve 43 is increased; when the liquid phase temperature in the first-effect separator 7 is greater than 75°C, the opening of the steam regulating valve 43 is reduced; when the liquid phase temperature in the first-effect separator 7 is greater than 85°C, the steam regulating valve 43 is closed;

[0080] S14, using the first-effect liquid level sensor 33 to monitor the liquid level in the first-effect separator 7, and adjusting the opening of the feed regulating valve 44 according to the liquid level in the first-effect separator 7, so that the liquid level in the first-effect separator 7 is maintained at 55%-60% of the preset liquid level upper limit;

[0081] S15, using the second effect liquid level sensor 37 to monitor the liquid level in the second effect separator 12, and adjusting the openings of the feed regulating valve 45 and the mother liquid reflux regulating valve 46 according to the liquid level in the second effect separator 12, the method is as follows:

[0082] S151, using the mother liquid level sensor 38 to monitor the liquid level in the mother liquid barrel 21, when it is monitored that the liquid level in the mother liquid barrel 21 is greater than 65% of the maximum liquid level of the mother liquid barrel 21, the mother liquid pump 22 is started; when it is monitored that the liquid level in the mother liquid barrel 21 is less than 40% of the maximum liquid level of the mother liquid barrel 21, the mother liquid pump 22 is stopped;

[0083] S152, when the liquid level in the secondary effect separator 12 is less than 60% of the maximum liquid level of the secondary effect separator 12, the openings of the feed regulating valve 45 and the mother liquid reflux regulating valve 46 are both increased;

[0084] When 60% of the maximum liquid level of the second-effect separator 12 ≤ the liquid level in the second-effect separator 12 < 63% of the maximum liquid level of the second-effect separator 12, the opening of the feed regulating valve 45 is reduced;

[0085] When 63% of the maximum liquid level of the secondary effect separator 12 ≤ the liquid level in the secondary effect separator 12 < 65% of the maximum liquid level of the secondary effect separator 12, close the material flow regulating valve 45 and reduce the opening of the mother liquid reflux regulating valve 46;

[0086] When the liquid level in the secondary effect separator 12 is ≥ 65% of the maximum liquid level of the secondary effect separator 12, the feed regulating valve 45 and the mother liquid reflux regulating valve 46 are closed;

[0087] S16. Use the density sensor 39 to monitor the density of the liquid feed at the outlet of the discharge pump 14. When it is monitored that the density of the liquid feed at the outlet of the discharge pump 14 reaches the preset density, open the discharge regulating valve 47 and close the return regulating valve 48; when it is monitored that the density of the liquid feed at the outlet of the discharge pump 14 is lower than the preset density, open the return regulating valve 48 and close the discharge regulating valve 47.

[0088] In this embodiment, the automatic flushing control method is as follows:

[0089] The feed pipeline and the discharge pipeline of the discharge pump 14 are flushed by using the anti-blocking method for the inlet and outlet pipelines of the discharge pump 14; the outlet of the mother liquor pump 22 is flushed by using the anti-blocking method for the mother liquor pump 22 pipeline; the feed pipeline of the centrifuge 17 is flushed by using the anti-blocking method for the feed pipeline of the centrifuge 17.

[0090] Among them, the anti-blocking method of the inlet and outlet pipelines of the discharge pump 14 is:

[0091] During the operation of the discharge pump 14, the inlet pipeline of the discharge pump 14 is flushed every 3 hours: the second flushing valve 52, the third flushing valve 53, the fourth flushing valve 54 and the fifth flushing valve 55 are closed, the flushing water pump 29 is started, the first flushing valve 51 is opened, the discharge pump 14 is started, and after flushing for 1 minute, the flushing water pump 29 and the first flushing valve 51 are closed, and the discharge pump 14 is stopped;

[0092] During the operation of the discharge pump 14, the outlet pipeline of the discharge pump 14 is flushed every 2 hours: the first flushing valve 51, the third flushing valve 53, the fourth flushing valve 54 and the fifth flushing valve 55 are closed, the flushing water pump 29 is started, the second flushing valve 52 is opened, the discharge pump 14 is started, and after flushing for 1 minute, the flushing water pump 29 and the second flushing valve 52 are closed, and the discharge pump 14 is stopped.

[0093] The method to prevent the mother liquid pump 22 pipeline from blocking is:

[0094] During the operation of the mother liquid pump 22, the outlet pipeline of the mother liquid pump 22 is flushed every 6 hours: the first flushing valve 51, the second flushing valve 52, the fourth flushing valve 54 and the fifth flushing valve 55 are closed, the flushing water pump 29 is started, the third flushing valve 53 is opened, the mother liquid pump 22 is started, and after flushing for 1 minute, the flushing water pump 29 and the third flushing valve 53 are closed, and the mother liquid pump 22 is stopped.

[0095] The method to prevent the centrifuge 17 feed pipeline from blocking is:

[0096] Before the centrifuge 17 is shut down, the feed pipeline of the centrifuge 17 is flushed: the first flushing valve 51, the second flushing valve 52, the third flushing valve 53 and the fifth flushing valve 55 are closed, the flushing water pump 29 is started, the fourth flushing valve 54 and the discharge regulating valve 49 are opened, and after flushing for 30 seconds, the fourth flushing valve 54 and the discharge regulating valve 49 are closed, the fifth flushing valve 55 is opened, and after flushing for 30 seconds, the flushing water pump 29 and the fifth flushing valve 55 are closed.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An automated control method for a high-concentration brine evaporation crystallization system, characterized in that: The high-concentration brine evaporation and crystallization system is controlled by the system load control method to ensure the water-salt balance in the system; after the high-concentration brine evaporation and crystallization system has been running for a certain period of time, the high-concentration brine evaporation and crystallization system is flushed by the automatic flushing control method to ensure the stable operation of the system; The system load control method comprises the following steps: S11, using a water inlet flow meter to monitor the water flow entering the raw material box, and calculating the average value of the water inlet flow into the raw material box; S12, according to the average value of the water inlet flow rate of the raw material box calculated in step S11, using the heat calculation formula, calculate the initial value of the steam flow rate entering the tube side of the first-effect heater, and adjust the initial opening of the steam regulating valve according to the initial value of the steam flow rate; S13, using a first-effect gas phase temperature sensor to monitor the liquid phase temperature in the first-effect separator, when the liquid phase temperature in the first-effect separator is less than 70°C, the steam regulating valve is opened wider; when the liquid phase temperature in the first-effect separator is greater than 75°C, the steam regulating valve is opened narrower; when the liquid phase temperature in the first-effect separator is greater than 85°C, the steam regulating valve is closed; S14, using a first-effect liquid level sensor to monitor the liquid level in the first-effect separator, and adjusting the opening of the feed regulating valve according to the liquid level in the first-effect separator, so that the liquid level in the first-effect separator is maintained at 55%-60% of the preset liquid level upper limit value; S15. Use the second-effect liquid level sensor to monitor the liquid level in the second-effect separator, and adjust the opening of the feed regulating valve and the mother liquid reflux regulating valve according to the liquid level in the second-effect separator. The method is as follows: S151, using a mother liquid level sensor to monitor the liquid level in the mother liquid barrel, when the liquid level in the mother liquid barrel is greater than 65% of the maximum liquid level in the mother liquid barrel, start the mother liquid pump; when the liquid level in the mother liquid barrel is less than 40% of the maximum liquid level in the mother liquid barrel, stop the mother liquid pump; S152. When the liquid level in the secondary effect separator is less than 60% of the maximum liquid level of the secondary effect separator, increase the opening of the feed regulating valve and the mother liquor reflux regulating valve; When 60% of the maximum liquid level of the second-effect separator is ≤ the liquid level in the second-effect separator < 63% of the maximum liquid level of the second-effect separator, reduce the opening of the feed regulating valve; When 63% of the maximum liquid level of the second-effect separator is ≤ the liquid level in the second-effect separator < 65% of the maximum liquid level of the second-effect separator, close the feed regulating valve and reduce the opening of the mother liquor reflux regulating valve; When the liquid level in the secondary effect separator is ≥ 65% of the maximum liquid level of the secondary effect separator, close the feed regulating valve and the mother liquor reflux regulating valve; S16, using a density sensor to monitor the density of the liquid at the outlet of the discharge pump, when it is monitored that the density of the liquid at the outlet of the discharge pump reaches a preset density, the discharge regulating valve is opened and the return regulating valve is closed; when it is monitored that the density of the liquid at the outlet of the discharge pump is lower than the preset density, the return regulating valve is opened and the discharge regulating valve is closed; The automatic flushing control method is as follows: Use the anti-blocking method for the inlet and outlet pipelines of the discharge pump to flush the feed pipeline of the discharge pump and the discharge pipeline of the discharge pump; use the anti-blocking method for the mother liquid pump pipeline to flush the outlet of the mother liquid pump; use the anti-blocking method for the centrifuge feed pipeline to flush the centrifuge feed pipeline; The method for preventing the inlet and outlet pipelines of the discharge pump from being blocked is as follows: During the operation of the discharge pump, flush the discharge pump inlet pipeline every 3 hours: close the second flushing valve, the third flushing valve, the fourth flushing valve and the fifth flushing valve, start the flushing water pump, open the first flushing valve, start the discharge pump, flush for 1 minute, close the flushing water pump and the first flushing valve, and stop the discharge pump; During the operation of the discharge pump, flush the discharge pump outlet pipeline every 2 hours: close the first flushing valve, the third flushing valve, the fourth flushing valve and the fifth flushing valve, start the flushing water pump, open the second flushing valve, start the discharge pump, flush for 1 minute, close the flushing water pump and the second flushing valve, and stop the discharge pump; The method for preventing the mother liquid pump pipeline from blocking is as follows: During the operation of the mother liquid pump, flush the outlet pipeline of the mother liquid pump every 6 hours: close the first flushing valve, the second flushing valve, the fourth flushing valve and the fifth flushing valve, start the flushing water pump, open the third flushing valve, start the mother liquid pump, flush for 1 minute, close the flushing water pump and the third flushing valve, and stop the mother liquid pump; The centrifuge feed pipeline anti-blocking method is: Before the centrifuge is shut down, flush the centrifuge feed pipeline: close the first flushing valve, the second flushing valve, the third flushing valve and the fifth flushing valve, start the flushing water pump, open the fourth flushing valve and the discharge regulating valve, flush for 30 seconds, close the fourth flushing valve and the discharge regulating valve, open the fifth flushing valve, flush for 30 seconds, and close the flushing water pump and the fifth flushing valve.

2. A system for realizing the automated control method of a high-concentration brine evaporation and crystallization system as claimed in claim 1, characterized in that: It includes a raw material box, a first-effect heater, a first-effect separator, a first-effect gas-liquid separator, a second-effect heater, a second-effect separator, a second-effect gas-liquid separator, a cyclone separator, a thickener, a centrifuge, a screw conveyor, a drying bed, a silo and a mother liquid barrel; The liquid outlet of the high-concentration brine water pipeline is connected to the liquid inlet of the raw material box, the liquid outlet of the raw material box is connected to the liquid inlet of the feed pump, the liquid outlet of the feed pump is connected to the first-effect circulation pipeline through a pipeline, the liquid outlet of the first-effect circulation pipeline is connected to the liquid inlet of the first-effect circulation pump, the liquid outlet of the first-effect circulation pump is connected to the shell-side inlet of the first-effect heater through a pipeline, the shell-side outlet of the first-effect heater is connected to the inlet of the first-effect separator through a pipeline, the liquid outlet at the bottom of the first-effect separator is connected to the liquid inlet of the first-effect circulation pipeline through a pipeline, the steam outlet at the top of the first-effect separator is connected to the inlet of the first-effect gas-liquid separator through a pipeline, the steam outlet of the first-effect gas-liquid separator is connected to the tube-side inlet of the second-effect heater through a pipeline, and the tube-side outlet of the second-effect heater is connected to the inlet of the second-effect separator through a pipeline; The first-effect circulation pipeline is also connected to the second-effect circulation pipeline through a pipeline, the liquid outlet of the second-effect circulation pipeline is connected to the liquid inlet of the second-effect circulation pump, the liquid outlet of the second-effect circulation pump is connected to the liquid inlet of the shell side of the second-effect heater through a pipeline, the liquid outlet of the shell side of the second-effect heater is connected to the inlet of the second-effect separator through a pipeline, and the liquid outlet in the middle of the second-effect separator is connected to the liquid inlet of the second-effect circulation pipeline through a pipeline; the discharge port at the bottom of the second-effect separator is connected to the inlet of the discharge pump through a pipeline, the outlet of the discharge pump is connected to the inlet of the cyclone separator through a discharge pipeline, the discharge port at the bottom of the cyclone separator is connected to the inlet of the thickener through a pipeline, the discharge port of the thickener is connected to the inlet of the centrifuge through a pipeline, the discharge port of the centrifuge is connected to the inlet of the screw conveyor, the outlet of the screw conveyor is connected to the inlet of the drying bed, and the outlet of the drying bed is connected to the inlet of the silo; The steam outlet at the top of the second-effect separator is connected to the inlet of the second-effect gas-liquid separator through a pipeline, and the steam outlet of the second-effect gas-liquid separator is connected to the inlet of the secondary steam condensate tank through a pipeline; The outlet of the secondary steam condensate tank is connected to the inlet of the condensate pump through a pipeline, and the outlet of the condensate pump is connected to the inlet of the recycling water tank through a pipeline; The outlet of the low-pressure steam pipeline is connected to the tube-side inlet of the first-effect heater, and the tube-side outlet of the first-effect heater is connected to the inlet of the recycled water tank through a pipeline; The liquid outlet of the cyclone separator, the liquid outlet of the thickener and the liquid outlet of the centrifuge are all connected to the inlet of the mother liquid barrel through a pipeline, the liquid outlet of the mother liquid barrel is connected to the inlet of the mother liquid pump through a pipeline, the outlet of the mother liquid pump is connected to the second-effect circulation pipeline through a pipeline, and a stirrer is provided in the mother liquid barrel; A first-effect liquid phase temperature sensor is provided at the bottom of the first-effect separator; a steam flow meter is provided at the outlet of the low-pressure steam pipeline, a steam regulating valve is provided at the pipe inlet of the first-effect heater; and a water inlet flow meter is provided at the liquid outlet of the high-concentration brine water pipeline; A first-effect liquid level sensor is provided in the first-effect separator; a feed flow meter and a feed regulating valve are provided in sequence along the liquid flow direction on the pipeline connecting the feed pump and the first-effect circulation pipeline; A first-effect gas phase temperature sensor and a first-effect pressure sensor are respectively provided at the steam outlet of the first-effect separator; a second-effect liquid level sensor is provided in the second-effect separator; a mother liquid level sensor is provided in the mother liquid barrel; a material transfer regulating valve is provided on the pipeline connecting the first-effect circulation pipeline and the second-effect circulation pipeline; a mother liquid reflux regulating valve is provided on the pipeline connecting the mother liquid pump and the second-effect circulation pipeline; A density sensor is provided at the outlet of the discharge pump, and a discharge regulating valve is provided on the discharge pipeline; the discharge pipeline upstream of the discharge regulating valve is also connected to the second-effect separator through a pipeline, and a return regulating valve is provided on the pipeline connecting the discharge pipeline and the second-effect separator; A liquid level sensor is provided in the thickener, and a discharge regulating valve is provided on a pipeline connecting the thickener and the centrifuge; A condensate level sensor is provided in the secondary steam condensate tank, and a condensate regulating valve is provided at the outlet of the condensate pump; The signal output ends of the first-effect liquid phase temperature sensor, the steam flowmeter, the water inlet flowmeter, the first-effect liquid level sensor, the feed flowmeter, the first-effect gas phase temperature sensor, the first-effect pressure sensor, the second-effect liquid level sensor, the mother liquid level sensor, the density sensor, the feed liquid level sensor, and the condensed water level sensor are all signal-connected to the signal input end of the controller, and the signal output end of the controller is signal-connected to the signal input end of the steam regulating valve, the feed regulating valve, the feed regulating valve, the mother liquid reflux regulating valve, the discharge regulating valve, the return regulating valve, the discharge regulating valve, and the condensed water regulating valve respectively; It also includes a flushing water tank, the water outlet of the flushing water tank is connected to the inlet of the flushing water pump through a pipeline, the outlet of the flushing water pump is divided into five routes, the first route is connected to the discharge port of the second-effect separator through a first flushing pipeline, the second route is connected to the discharge pipeline upstream of the discharge regulating valve through a second flushing pipeline, the third route is connected to the liquid outlet of the mother liquid barrel through a third flushing pipeline, the fourth route is connected to the discharge port of the thickener through a fourth flushing pipeline, and the fifth route is connected to the inlet of the centrifuge through a fifth flushing pipeline; A first flushing valve is provided on the first flushing pipeline, a second flushing valve is provided on the second flushing pipeline, a third flushing valve is provided on the third flushing pipeline, a fourth flushing valve is provided on the fourth flushing pipeline, and a fifth flushing valve is provided on the fifth flushing pipeline.

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