Automatic salt discharging device of shale gas produced water evaporative crystallization system

Abstract

The invention relates to the technical field of shale gas exploitation, and discloses an automatic salt discharging device of a shale gas produced water evaporation crystallization system, which comprises a falling film evaporator and an outlet pipeline, and also comprises a brine mixing pipeline used for introducing brine into the outlet pipeline and flushing the outlet pipeline, and the brine mixing pipeline is connected to the outlet pipeline; a brine supply device; the brine supply device is connected with the brine mixing pipeline; the brine mixing control valve is used for controlling brine to flow into and stop flowing into the outlet pipeline; the outlet control valve is used for controlling the outflow and stop of the crystalline salt in the outlet pipeline; and the control system is used for receiving signals of the outlet control valve and the brine mixing control valve and controlling opening and closing of the outlet control valve and the brine mixing control valve. The problem that an existing outlet pipeline is prone to being blocked can be solved, and the evaporative crystallization effect and the treatment efficiency of the system on wastewater are improved.

Description

Technical Field

[0001] The invention relates to the technical field of shale gas exploitation, and in particular to an automatic salt-discharging device for a shale gas produced water evaporation and crystallization system. Background Art

[0002] Shale gas is a gaseous fossil fuel. During the extraction of shale gas, some industrial wastewater will be generated, such as fracturing flowback fluid or drilling wastewater. These wastewaters usually contain high concentrations of pollutants such as salt, organic matter, heavy metals and suspended matter, so they need to be treated to prevent secondary pollution.

[0003] When treating water, a falling film evaporator is currently usually used for evaporation and crystallization. The principle is that by forming a thin film on the inner wall of the heating tube of the falling film evaporator and flowing down the tube wall, the heat energy can be efficiently used for evaporation, thereby improving the efficiency of wastewater treatment. Wastewater treated by the falling film evaporator can be further treated by crystallization, drying, etc. to obtain valuable salts or other compounds. These compounds can be reused as industrial raw materials, realizing the resource utilization of wastewater.

[0004] However, in actual application, since this type of liquid contains more inorganic salts, these salts are very easy to form crystals on the wall of the crystallization salt outlet pipeline of the falling film evaporator after supersaturation, causing the outlet pipeline to be blocked, destroying the evaporation crystallization effect and processing efficiency of the system. In order to avoid pipeline blockage, currently manual observation is carried out at the crystallization salt outlet 24 hours a day. When the salt output is abnormal, it can be inferred that the pipeline is blocked, and the system is manually controlled and adjusted to ensure the normal operation of the system. However, this method of manual duty and control and adjustment is very labor-intensive and seriously affects the efficient operation of the enterprise. Summary of the invention

[0005] The present invention aims to provide an automatic salt outlet device for a shale gas produced water evaporation and crystallization system to solve the problem that the existing export pipeline is easily blocked and improve the evaporation and crystallization effect and treatment efficiency of the system on wastewater.

[0006] To achieve the above object, the present invention adopts the following technical solution: an automatic salt output device of a shale gas produced water evaporation and crystallization system, comprising a falling film evaporator and an outlet pipeline connected to the outlet of the falling film evaporator, and also comprising:

[0007] The brine mixing pipeline is used to introduce brine into the export pipeline and flush the export pipeline. The brine mixing pipeline is connected to the export pipeline;

[0008] The brine supply device is used to provide brine for flushing the outlet pipeline to the brine mixing pipeline; the brine supply device is connected to the brine mixing pipeline;

[0009] The brine control valve is used to control the flow of brine into and stop the flow of brine into the export pipeline; the brine control valve is installed on the brine pipeline and is located between the brine supply device and the export pipeline;

[0010] The outlet control valve is used to control the outflow and stop of the crystallized salt in the outlet pipeline. The outlet control valve is arranged at the end of the outlet pipeline. The connection part between the brine addition pipeline and the outlet pipeline is located between the falling film evaporator and the outlet control valve.

[0011] The control system is connected to the brine addition control valve and the outlet control valve at the same time. The control system is used to receive signals from the outlet control valve and the brine addition control valve and control the outlet control valve and the brine addition control valve to open and close.

[0012] The principle and advantages of this scheme are: in this scheme, a brine flushing mechanism is introduced into the export pipeline by setting up a brine pipeline, a brine supply device and a brine control valve. In actual application, brine generally has a high concentration. Since brine has a high salt concentration and solubility, it can effectively dissolve and flush the crystallized salt on the pipe wall, thereby preventing the blockage caused by crystallization in the export pipeline. At the same time, the brine control valve and the export control valve are automatically controlled by the control system to achieve precise regulation of the brine flushing and salt output process. When the export pipeline is blocked to a certain extent and affects the salt output efficiency, the control system will automatically open the export control valve and adjust the opening to ensure the appropriate amount of salt output. If the salt output stops suddenly, it means that the export pipeline is blocked. At this time, the control system will automatically open the brine control valve and introduce brine to flush the export pipeline.

[0013] The advantages of this solution are:

[0014] 1. High degree of automation: Through the automatic control system, precise control of brine flushing and salt output process is achieved, without manual supervision and intervention, which greatly improves work efficiency.

[0015] 2. Good anti-clogging effect: The brine flushing mechanism can effectively dissolve and flush the crystallized salt on the pipe wall, prevent the occurrence of blockage, and ensure the normal operation of the system.

[0016] 3. High salt output efficiency and good crystallization effect: By automatically controlling the outlet control valve, continuous and stable discharge of crystallized salt can be achieved, which is beneficial to improving the system's evaporation crystallization effect and treatment efficiency of wastewater.

[0017] 4. Reduce maintenance costs: Since the need for manual supervision and intervention is reduced, the maintenance cost of equipment is reduced, and the labor intensity of staff is also reduced.

[0018] In general, this solution effectively solves the problem of easy blockage of the export pipeline during the evaporation and crystallization of shale gas produced water by introducing a brine flushing mechanism and an automated control system, thereby improving the system's working efficiency and crystallization effect and reducing maintenance costs.

[0019] Preferably, as an improvement, it further comprises a purified water pipeline, the purified water pipeline is used to introduce purified water into the outlet pipeline and flush the outlet pipeline, and the purified water pipeline is connected to the outlet pipeline between the falling film evaporator and the outlet control valve;

[0020] A purified water supply device, the purified water supply device is used to provide purified water for flushing the outlet pipeline to the purified water pipeline, and the purified water supply device is connected to the purified water pipeline;

[0021] A flushing control valve is used to control the flow of purified water into and stop the flow of purified water into the outlet pipeline; the flushing control valve is arranged on the purified water pipeline and is located between the purified water supply device and the outlet pipeline;

[0022] The control system is also connected to the flushing control valve, and is also used to receive a signal from the flushing control valve and control the flushing control valve to open and close.

[0023] Through the above scheme, a purified water flushing mechanism is introduced by adding purified water pipelines, purified water supply devices and flushing control valves, so that the system has dual flushing capabilities. On the basis of the original brine flushing, purified water can be used as a milder but equally effective flushing medium to flush the export pipeline regularly or on demand, further reducing the accumulation of crystallized salt on the pipe wall and improving the anti-blocking effect. The automated control system can monitor and adjust the flushing process in real time to ensure that the flushing medium flows into the export pipeline at the appropriate time and under appropriate conditions. This intelligent control method improves the stability and reliability of the system and reduces the risk of failure and downtime caused by human operating errors.

[0024] Preferably, as an improvement, it also includes a weighing module, which is used to monitor the weight of the crystallized salt discharged from the outlet pipeline; the control system is also connected to the weighing module, and the control system is also used to receive the signal of the weighing module and adjust the opening of the outlet control valve when the weight of the crystallized salt reaches a set threshold.

[0025] Through the above scheme, the weighing module can monitor the weight of the crystallized salt discharged from the outlet pipeline in real time, ensuring that the system can accurately control the amount of salt output. When the weight of the crystallized salt reaches the set threshold, the control system will automatically adjust the opening of the outlet control valve to avoid blockage or waste of resources caused by too much or too little salt output. The integration of the weighing module and the control system enables the system to automatically monitor and adjust the salt output process without manual intervention. This greatly improves the automation of the system, reduces the errors and uncertainties caused by manual operation, and also reduces the labor intensity of the staff. And through the real-time data provided by the weighing module, the system can more accurately understand the salt output during the production process, thereby understanding the pipeline blockage and optimizing the production process in a targeted manner. For example, the processing parameters of brine or purified water can be adjusted according to the output of crystallized salt to improve the flushing efficiency and flushing quality of the export pipeline.

[0026] Preferably, as an improvement, the control system is also used to control the brine addition control valve to open when the weighing module detects that the weight of the crystallized salt discharged from the outlet pipeline does not change within a set time period threshold t1.

[0027] Through the above scheme, by setting the time period threshold t1, the control system can monitor the weight change of the crystallized salt in the export pipeline in real time. If the weight of the crystallized salt does not change within the time t1, it means that the export pipeline is blocked. At this time, the control system automatically opens the brine control valve and introduces brine to flush the export pipeline, thereby clearing the export pipeline in time to keep the export pipeline unobstructed.

[0028] Preferably, as an improvement, the control system is further used to control the flushing control valve to open when the weighing module detects that the weight of the crystallized salt discharged from the outlet pipeline does not change within a set time period threshold t2.

[0029] Through the above scheme, by setting two different time period thresholds t1 and t2, corresponding to brine flushing and purified water flushing respectively, the system implements a multi-level anti-blocking strategy, which can more comprehensively deal with different types of blockage problems and improve the adaptability and reliability of the system.

[0030] Preferably, as an improvement, the control system is also used to adjust the opening time and opening degree of the brine control valve and the flushing control valve when the weighing module detects that the flow rate of the mixture of crystallized salt and brine or the mixture of crystallized salt and purified water discharged from the outlet pipeline reaches V.

[0031] Through the above scheme, by real-time detection of the flow rate of the mixed liquid, the control system can accurately adjust the opening time and opening degree of the brine control valve and the flushing control valve, thereby achieving precise control of the flow rate of the mixed liquid, reducing the frequency and difficulty of manual intervention, while avoiding the waste of raw materials and improving resource utilization efficiency.

[0032] Preferably, as an improvement, the brine supply device includes a storage tank for storing brine and a pump for conveying the brine from the storage tank to the brine mixing pipeline.

[0033] Through the above solution, the storage tank can store a large amount of brine, ensuring that it can be continuously and stably supplied to the brine-mixing pipeline when needed to meet production needs. Through a special pumping system, brine can be efficiently transported from the storage tank to the brine-mixing pipeline, reducing energy consumption and time costs during the transportation process.

[0034] Preferably, as an improvement, the purified water supply device comprises a water storage tank for storing purified water and a pump for conveying purified water from the water storage tank to the purified water pipeline.

[0035] Through the above solution, the water tank can store enough purified water to ensure continuous and stable supply to the purified water pipeline when needed, meeting the water demand in various application scenarios. The efficient operation of the pumping system enables the purified water to be quickly and accurately delivered to the designated location, improving water efficiency.

[0036] Preferably, as an improvement, the control system is a programmable logic controller system, which has the ability to receive input signals, process signals and output control instructions according to a preset program.

[0037] Through the above scheme, the use of a programmable logic controller system as a control system has the advantages of high reliability and stability, high programmability and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0039] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.

[0040] The reference numerals in the drawings of the specification include: falling film evaporator 1, outlet pipeline 2, brine addition pipeline 3, brine addition control valve 4, outlet control valve 5, purified water pipeline 6, flushing control valve 7.

[0041] Example 1

[0042] An automatic salt-discharging device for evaporation and crystallization system of shale gas produced water, such as Figure 1 As shown, it includes a falling film evaporator 1 and an outlet pipeline 2 connected to the outlet of the falling film evaporator 1, and also includes:

[0043] The brine mixing pipeline 3 is used to introduce brine into the export pipeline 2 and flush the export pipeline 2. The brine mixing pipeline 3 is connected to the export pipeline 2;

[0044] The brine supply device is used to provide brine for flushing the outlet pipeline 2 to the brine mixing pipeline 3; the brine supply device is connected to the brine mixing pipeline 3; the brine supply device includes a storage tank for storing brine and a pump for transporting brine from the storage tank to the brine mixing pipeline 3.

[0045] The brine adjustment control valve 4 is used to control the flow of brine into and stop the flow of brine into the outlet pipeline 2; the brine adjustment control valve 4 is arranged on the brine adjustment pipeline 3 and is located between the brine supply device and the outlet pipeline 2; the brine adjustment control valve 4 in this embodiment can be implemented by, for example, the NETZSCH pneumatic regulating valve ZJHP series.

[0046] The outlet control valve 5 is used to control the outflow and stop of the crystallized salt in the outlet pipeline 2. The outlet control valve 5 is arranged at the end of the outlet pipeline 2. The connection part between the brine addition pipeline 3 and the outlet pipeline 2 is located between the falling film evaporator 1 and the outlet control valve 5. The outlet control valve 5 in this embodiment can be implemented by, for example, the NETZSCH pneumatic regulating valve ZJHP series.

[0047] The control system is connected to the brine control valve 4 and the outlet control valve 5 at the same time. The control system is used to receive signals from the outlet control valve 5 and the brine control valve 4 and control the outlet control valve 5 and the brine control valve 4 to open and close. The control system is a programmable logic controller (PLC) system, which has the ability to receive input signals, process signals and output control instructions according to a preset program. The control system in this embodiment can be implemented by, for example, the Siemens S7-300 series.

[0048] In actual operation, when the crystallized salt in the outlet pipeline 2 needs to be discharged, the control system controls the outlet control valve 5 to open, and the crystallized salt flows out from the outlet pipeline 2. When the outlet pipeline 2 needs to be flushed, the control system controls the brine addition control valve 4 to open, and brine flows from the brine addition pipeline 3 into the outlet pipeline 2 to flush the pipeline.

[0049] Example 2

[0050] The automatic salt output device of the shale gas produced water evaporation crystallization system in this embodiment is as follows: Figure 1 , based on Example 1, further comprising a purified water pipeline 6, the purified water pipeline 6 is used to introduce purified water into the outlet pipeline 2 and flush the outlet pipeline 2, the purified water pipeline 6 is connected to the outlet pipeline 2 between the falling film evaporator 1 and the outlet control valve 5;

[0051] The purified water supply device is used to provide purified water for flushing the outlet pipeline 2 to the purified water pipeline 6, and the purified water supply device is connected to the purified water pipeline 6; the purified water supply device includes a water tank for storing purified water and a pump for transporting purified water from the water tank to the purified water pipeline 6.

[0052] The flushing control valve 7 is used to control the flow of purified water into and stop the flow of purified water into the outlet pipeline 2; the flushing control valve 7 is arranged on the purified water pipeline 6 and is located between the purified water supply device and the outlet pipeline 2; the flushing control valve 7 in this embodiment also adopts the NETZSCH pneumatic regulating valve ZJHP series.

[0053] The control system is also connected to the flushing control valve 7, and is also used to receive the signal of the flushing control valve 7 and control the flushing control valve 7 to open and close.

[0054] In actual operation, when the outlet pipeline 2 needs to be flushed with purified water, the control system controls the flushing control valve 7 to open, and purified water flows from the purified water pipeline 6 into the outlet pipeline 2 to flush the pipeline.

[0055] Example 3

[0056] The automatic salt output device of the shale gas produced water evaporation crystallization system in this embodiment, on the basis of the previous embodiment, further includes a weighing module, which is used to monitor the weight of the crystallized salt discharged from the outlet pipeline 2; the control system is also connected to the weighing module, and the control system is also used to receive the signal of the weighing module and adjust the opening of the outlet control valve 5 when the weight of the crystallized salt reaches a set threshold. The weighing module in this embodiment can be specifically implemented by, for example, GX-NS-300kg of AC Company of the United States.

[0057] The control system is also used to control the brine addition control valve 4 to open when the weighing module detects that the weight of the crystallized salt discharged from the outlet pipeline 2 does not change within a set time period threshold t1.

[0058] The control system is also used to control the flushing control valve 7 to open when the weighing module detects that the weight of the crystallized salt discharged from the outlet pipeline 2 does not change within a set time period threshold t2.

[0059] The control system is also used to adjust the opening time and opening degree of the brine control valve and the flushing control valve 7 when the weighing module detects that the flow rate of the mixture of crystallized salt and brine or the mixture of crystallized salt and purified water discharged from the outlet pipeline 2 reaches V.

[0060] The specific implementation process is as follows:

[0061] The crystallized salt is discharged through the outlet pipeline 2, and the weighing module starts to monitor the weight of the crystallized salt. When the weight of the crystallized salt reaches the set threshold, the control system automatically adjusts the opening of the outlet control valve 5 to control the discharge speed of the crystallized salt to ensure that the amount of crystallized salt discharged meets the preset requirements.

[0062] During the discharge of the crystallized salt, the weighing module continuously monitors the weight of the crystallized salt discharged from the outlet pipeline 2. When the weight of the crystallized salt does not change within the set time period threshold t1, it indicates that the crystallized salt is not continuously discharged and the outlet pipeline 2 is blocked. At this time, after the control system receives the signal from the weighing module, it controls the brine control valve 4 to open, and the brine flows from the brine pipeline 3 into the outlet pipeline 2 to flush the outlet pipeline 2. During the flushing process, the control system can adjust the flow rate and flushing time of the brine as needed.

[0063] Similarly, the weighing module continuously monitors the weight of the crystallized salt discharged from the outlet pipeline 2. When the weight of the crystallized salt remains unchanged within the set time period threshold t2 (in actual application, t2 is greater than t1), it indicates that the brine flushing may not completely solve the problem or the system has completed the discharge of the crystallized salt. At this time, purified water is required for further flushing. After the control system receives the signal from the weighing module, it controls the flushing control valve 7 to open, and purified water flows from the purified water pipeline 6 into the outlet pipeline 2 to flush the outlet pipeline 2. During the flushing process, the control system can also adjust the flow rate and flushing time of the purified water as needed.

[0064] During the process of flushing the outlet pipeline 2 with brine or purified water, the weighing module also monitors in real time the flow rate of the mixture of crystallized salt and brine or the mixture of crystallized salt and purified water discharged from the outlet pipeline 2. When the flow rate reaches the preset flow rate V, it means that the outlet pipeline 2 is basically unblocked. At this time, the control system will automatically adjust the opening time and opening degree of the brine control valve and the flushing control valve 7 to control the flushing effect and ensure that the flushing process is both effective and economical.

[0065] During the entire operation process, the control system will monitor the operating status and parameter changes of each part in real time to ensure the stable operation of the system.

[0066] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An automatic salt outlet device for shale gas produced water evaporation and crystallization system, comprising a falling film evaporator and an outlet pipeline connected to the outlet of the falling film evaporator, characterized in that: Also includes: The brine mixing pipeline is used to introduce brine into the export pipeline and flush the export pipeline. The brine mixing pipeline is connected to the export pipeline; The brine supply device is used to provide brine for flushing the outlet pipeline to the brine mixing pipeline; the brine supply device is connected to the brine mixing pipeline; The brine control valve is used to control the flow of brine into and stop the flow of brine into the export pipeline; the brine control valve is installed on the brine pipeline and is located between the brine supply device and the export pipeline; The outlet control valve is used to control the outflow and stop of the crystallized salt in the outlet pipeline. The outlet control valve is arranged at the end of the outlet pipeline. The connection part between the brine addition pipeline and the outlet pipeline is located between the falling film evaporator and the outlet control valve. The control system is connected to the brine addition control valve and the outlet control valve at the same time. The control system is used to receive signals from the outlet control valve and the brine addition control valve and control the outlet control valve and the brine addition control valve to open and close.

2. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 1 is characterized in that: Also includes: A purified water pipeline, which is used to introduce purified water into the outlet pipeline and flush the outlet pipeline, and the purified water pipeline is connected to the outlet pipeline between the falling film evaporator and the outlet control valve; A purified water supply device, the purified water supply device is used to provide purified water for flushing the outlet pipeline to the purified water pipeline, and the purified water supply device is connected to the purified water pipeline; A flushing control valve is used to control the flow of purified water into and stop the flow of purified water into the outlet pipeline; the flushing control valve is arranged on the purified water pipeline and is located between the purified water supply device and the outlet pipeline; The control system is also connected to the flushing control valve, and the control system is also used to receive a signal from the flushing control valve and control the flushing control valve to open and close.

3. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 2 is characterized in that: It also includes a weighing module, which is used to monitor the weight of the crystallized salt discharged from the outlet pipeline; the control system is also connected to the weighing module, and the control system is also used to receive the signal of the weighing module and adjust the opening of the outlet control valve when the weight of the crystallized salt reaches a set threshold.

4. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 3 is characterized in that: The control system is also used to control the brine addition control valve to open when the weighing module detects that the weight of the crystallized salt discharged from the outlet pipeline does not change within a set time period threshold t1.

5. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 4 is characterized in that: The control system is further used to control the flushing control valve to open when the weighing module detects that the weight of the crystallized salt discharged from the outlet pipeline does not change within a set time period threshold t2.

6. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 5, characterized in that: The control system is also used to adjust the opening time and opening degree of the brine control valve and the flushing control valve when the weighing module detects that the flow rate of the mixture of crystallized salt and brine or the mixture of crystallized salt and purified water discharged from the outlet pipeline reaches V.

7. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 6, characterized in that: The brine supply device includes a storage tank for storing brine and a pump for transporting the brine from the storage tank to the brine mixing pipeline.

8. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 7, characterized in that: The purified water supply device includes a water storage tank storing purified water and a pump for transferring purified water from the water storage tank to a purified water pipeline.

9. The automatic salt-discharging device of the shale gas produced water evaporation and crystallization system according to claim 8, characterized in that: The control system is a programmable logic controller system, which has the ability to receive input signals, process signals and output control instructions according to a preset program.

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