Electric control device for biogas slurry thermal hydrolysis coupled ammonia removal system and method thereof

Abstract

The present application relates to a kind of electrical control device and its method for biogas slurry thermal hydrolysis coupling ammonia removal system, comprising the following steps: in PID control unit, the high and low threshold of the data corresponding to each probe and the high and low threshold of the pressure difference in flash separator, thermal hydrolysis reactor are set;Start biogas slurry thermal hydrolysis coupling ammonia removal system and its electrical control device, PID control unit compares the data obtained by probe with threshold, controls the start-stop of pulping screw feed pump, thermal hydrolysis feed pump and valve.The beneficial effects of the present application are: by selectively adding liquid level probe, temperature probe and pressure sensor probe in pulping reactor, thermal hydrolysis reactor and flash separator, data collection is carried out, and through the calculation of PLC control system, flash separator and biogas slurry thermal hydrolysis reuse system are cooperated with each other, the removal rate of ammonia in biogas slurry is improved;Automatic operation of biogas slurry thermal hydrolysis coupling ammonia removal system is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of biogas slurry treatment, and particularly relates to an electrical control device for a biogas slurry thermal hydrolysis coupled ammonia removal system and a method thereof. BACKGROUND

[0002] The biogas slurry thermal hydrolysis recycling process is to treat the mixed liquid by high-temperature and high-pressure steam, and under the action of thermal hydrolysis and flash steam explosion, the biogas slurry is converted into easily degradable organic matter, and then the biogas slurry rich in easily degradable organic matter is returned to the anaerobic fermentation system for secondary fermentation, so as to realize partial recycling of the biogas slurry, increase the gas production rate of the raw material in the anaerobic fermentation system, and shorten the fermentation time of the raw material. After the thermal hydrolysis recycling process, the amount of biogas slurry in the biogas project can be greatly reduced.

[0003] However, the biogas slurry after anaerobic fermentation of the organic waste in the anaerobic fermentation system contains high-concentration ammonia in the form of NH3 and NH4+. Too high ammonia will inhibit the activity of methanogenic bacteria, resulting in a decrease in the gas production rate. In the biogas slurry thermal hydrolysis recycling process, there is no ammonia removal effect, and when the biogas slurry is recycled, the biogas slurry rich in ammonia is transported back to the anaerobic fermentation system, resulting in a continuous increase in the ammonia concentration in the raw material in the anaerobic fermentation system. After multiple cycles of recycling, the ammonia concentration can reach more than 3000 mg / L, which eventually reduces the gas production rate and leads to unstable operation of the whole process system. The existing technology can perform basic ammonia removal treatment by adding an ammonia removal device in the anaerobic fermentation system, but due to the lack of corresponding electrical control devices and methods, it is difficult to effectively make the traditional anaerobic fermentation system and the ammonia removal device cooperate with each other to form an effective coupled system.

[0004] Therefore, it is necessary to develop a process matching electrical control device and method which can solve the above technical problems. SUMMARY

[0005] The present application aims to overcome the deficiencies in the prior art and provide an electrical control device for a biogas slurry thermal hydrolysis coupled ammonia removal system and a method thereof.

[0006] The electrical control device for the biogas slurry thermal hydrolysis coupled ammonia removal system comprises a power supply, and the power supply is connected in parallel with a pulping reactor, a thermal hydrolysis reactor, a pulping screw feeder pump, a thermal hydrolysis feeder pump, a PLC and a valve power supply, a control power supply and a direct-current switching power supply, and a circuit breaker is arranged on each parallel branch, and a circuit breaker is also arranged on the power supply;

[0007] The pulping reactor is provided with a liquid level probe and a temperature probe, the thermal hydrolysis reactor is provided with a temperature probe and a pressure sensor probe, and the flash separator is provided with a liquid level probe and a pressure sensor probe;

[0008] The valve includes an electric switch valve from the hot water hydrolysis reactor to the flash separator, a steam reflux valve from the flash separator to the slurry reactor and a steam regulating valve to the hot water hydrolysis reactor; the valves are connected in parallel between the PLC and the branch of the valve power supply, and a circuit breaker is arranged on the branch of the valve.

[0009] All the probes are connected to the input card of the PLC, the slurry screw feed pump, the hot water hydrolysis feed pump and all the valves are connected to the output card of the PLC, and the PLC includes a PID control unit for automatic adjustment.

[0010] As preferred, the slurry screw feed pump is arranged in the feed pipeline of the slurry reactor, and the hot water hydrolysis feed pump is arranged in the pipeline from the slurry reactor to the hot water hydrolysis feed pump.

[0011] As preferred, a frequency converter is arranged on each of the parallel branches of the slurry reactor, the hot water hydrolysis reactor, the slurry screw feed pump and the hot water hydrolysis feed pump.

[0012] As preferred, a slurry reactor fan is further connected in parallel on the parallel branch of the slurry reactor, a slurry reactor fan is further connected in parallel on the parallel branch of the hot water hydrolysis reactor, and a slurry screw feed pump fan is further connected in parallel on the parallel branch of the slurry screw feed pump; and a circuit breaker is arranged in each of the branches of the slurry reactor fan, the slurry reactor fan and the slurry screw feed pump fan.

[0013] The control method of the electrical control device for the biogas slurry hot water hydrolysis coupling ammonia removal system comprises the following steps:

[0014] Step one: install the electrical control device for the biogas slurry hot water hydrolysis coupling ammonia removal system at the biogas slurry hot water hydrolysis coupling ammonia removal system and connect it to the power supply;

[0015] Step two: connect the liquid level probe and temperature probe in the slurry reactor, the temperature probe and pressure sensor probe in the hot water hydrolysis reactor, and the liquid level probe and pressure sensor probe in the flash separator to the PLC input / output card in the electrical control device, and set the high and low thresholds of the corresponding data of each probe and the high and low thresholds of the pressure difference in the flash separator and the hot water hydrolysis reactor in the PID control unit;

[0016] Step three: send power to the total incoming line switch in the electrical control device, then turn on the control power switch, and finally turn on the power switch of the process equipment, check the display state of each indicator light, and enter the pre-start stage;

[0017] Step four: start the biogas slurry hot water hydrolysis coupling ammonia removal system and its electrical control device, the PID control unit compares the data obtained by the probes with the thresholds, and controls the start and stop of the slurry screw feed pump, the hot water hydrolysis feed pump and the valves.

[0018] As preferred, in step four:

[0019] The pulping screw feed pump is started when the liquid level in the pulping reactor is below the low threshold value, and is stopped when the liquid level in the pulping reactor is above the high threshold value.

[0020] The over steam reflux valve is opened when the liquid level or temperature in the pulping reactor is below the low threshold value, and is stopped when the liquid level or temperature in the pulping reactor is above the high threshold value.

[0021] The steam regulating valve is opened when the pressure in the hot hydrolysis reactor is below the low threshold value, and is stopped when the pressure in the hot hydrolysis reactor is above the high threshold value.

[0022] As preferred, in step four:

[0023] The hot hydrolysis feed pump is started when the liquid level in the pulping reactor or the temperature in the hot hydrolysis reactor is below the low threshold value, and is stopped when the liquid level in the pulping reactor or the temperature in the hot hydrolysis reactor is above the high threshold value.

[0024] Meanwhile, the hot hydrolysis feed pump is also started when the liquid level in the flash separator is below the low threshold value, and is stopped when the liquid level in the flash separator is above the high threshold value.

[0025] As preferred, in step four: the electric switch valve is started when the difference between the flash separator and the hot hydrolysis reactor is below the low threshold value, and is stopped when the difference between the flash separator and the hot hydrolysis reactor is above the high threshold value.

[0026] Meanwhile, the electric switch valve is also started when the liquid level in the flash separator is below the low threshold value, and is stopped when the liquid level in the flash separator is above the high threshold value.

[0027] As preferred, during operation, the operation data of the biogas slurry hot hydrolysis and ammonia removal system are uploaded to the user end for real-time analysis, monitoring and storage.

[0028] The beneficial effects of the present application are:

[0029] 1) The present application improves the removal rate of ammonia in biogas slurry by selectively adding liquid level probes, temperature probes and pressure sensor probes in the pulping reactor, the hot hydrolysis reactor and the flash separator, collecting data, and calculating through the PLC control system, so that the flash separator and the biogas slurry hot hydrolysis and reuse system cooperate with each other.

[0030] 2) The present application realizes the automatic operation of the biogas slurry thermal hydrolysis coupling ammonia removal system through the PLC control of the biogas slurry thermal hydrolysis coupling ammonia removal system, makes the biogas slurry thermal hydrolysis coupling ammonia removal system run more stably and reliably, improves the biogas production, reduces the negative influence on the anaerobic fermentation system, eliminates manual intervention, and achieves the energy saving and environmental protection requirements. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is an electrical main wiring diagram for the electrical control device of the biogas slurry thermal hydrolysis coupling ammonia removal system.

[0032] Figure 2 It is a structural schematic diagram of the biogas slurry thermal hydrolysis coupling ammonia removal system.

[0033] Figure 3 It is a PLC automatic control flow chart of the biogas slurry thermal hydrolysis coupling ammonia removal system. DETAILED DESCRIPTION

[0034] The present application will be further described below in conjunction with examples. The following examples are only used to help understand the present application. It should be pointed out that for ordinary people in the technical field, some modifications can be made without departing from the principles of the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0035] Example 1

[0036] As an example, as shown in Figure 1 and Figure 2 , the biogas slurry thermal hydrolysis coupling ammonia removal system includes a slurry reactor, a thermal hydrolysis reactor and a flash separator, and is also connected with a control box, a monitor, an emergency stop button, a control button, an indicator light, a controller communication unit and a surge protection module. The electrical control device panel is in situ / remote location, and one-key start / stop is realized through the monitor.

[0037] The electrical control device for the biogas slurry thermal hydrolysis coupling ammonia removal system includes a power supply, which provides a power supply meeting the power quality requirements for the electrical control device. A frequency converter connected to the slurry reactor is connected to the power supply through a circuit breaker QF1; a frequency converter connected to the thermal hydrolysis reactor is connected to the power supply through a circuit breaker QF2; a slurry screw feed pump is connected to the power supply through a circuit breaker QF3; a thermal hydrolysis feed pump is connected to the power supply through a circuit breaker QF4; a PLC and a valve power supply are connected to the power supply through a circuit breaker QF5; a control power supply is connected to the power supply through a circuit breaker QF6; and a DC switching power supply AC / DC is connected to the power supply through a circuit breaker QF7. A circuit breaker QF is also provided on the power supply to control the switching of the entire power supply circuit.

[0038] The electrical circuit is also connected with a monitor, an emergency stop button, a control button, an indicator lamp, a controller communication unit and a surge protection module. The monitor provides an operation or setting manual friendly interface under different permissions for field operation and maintenance personnel. The frequency converter automatically tracks the controlled object device and has operation feedback and fault feedback functions, and is a core device for realizing intelligent adjustment and energy saving and environmental protection.

[0039] The emergency stop button is a safety component of the system, directly connected in series in the electrical circuit to ensure the safety of personnel and equipment in the first time. The control button is an electric element for manual on-site operation, and the indicator lamp is an electric element for manual on-site inspection and monitoring.

[0040] A slurry reactor fan is connected in parallel on the parallel branch where the slurry reactor is located through a circuit breaker QF1', a hot hydrolysis reactor fan is connected in parallel on the parallel branch where the hot hydrolysis reactor is located through a circuit breaker QF2', and a slurry screw feed pump fan is connected in parallel on the parallel branch where the slurry screw feed pump is located through a circuit breaker QF3'.

[0041] The slurry screw feed pump is arranged in the feed pipeline of the slurry reactor, and the hot hydrolysis feed pump is arranged in the pipeline leading from the slurry reactor to the hot hydrolysis feed pump.

[0042] A liquid level probe and a temperature probe are arranged in the slurry reactor, a temperature probe and a pressure sensor probe are arranged in the hot hydrolysis reactor, and a liquid level probe and a pressure sensor probe are arranged in the flash separator;

[0043] The valves include an electrically operated on-off valve leading from the hot hydrolysis reactor to the flash separator, a steam reflux valve leading from the flash separator to the slurry reactor, and a steam regulating valve leading to the hot hydrolysis reactor. The valves are arranged in parallel with each other in the branch of the PLC and the valve power supply, and a circuit breaker is arranged on the branch where the valves are located.

[0044] All the probes are connected to the input card of the PLC, the slurry screw feed pump, the hot hydrolysis feed pump and all the valves are connected to the output card of the PLC, and the PLC includes a PID control unit for realizing automatic adjustment.

[0045] Example Two

[0046] As another embodiment, the control method of the electrical control device for the biogas slurry hot hydrolysis coupling ammonia removal system proposed in Example One includes the following steps:

[0047] Step One: Install the electrical control device for the biogas slurry hot hydrolysis coupling ammonia removal system at the biogas slurry hot hydrolysis coupling ammonia removal system and connect to the power supply;

[0048] Step 2: Connect the level probe and temperature probe in the slurry reactor, the temperature probe and pressure sensor probe in the hot hydrolysis reactor, and the level probe and pressure sensor probe in the flash separator to the PLC input / output card in the electrical control device, and set the high and low threshold values ​​for the corresponding data of each probe and the pressure difference threshold values ​​for the flash separator and the hot hydrolysis reactor in the PID control unit.

[0049] Step 3: Power on the main incoming line switch in the electrical control device, then close the control power switch, and finally close the power switch of the process equipment. Check the display status of each indicator light and enter the pre-start stage.

[0050] Step 4: Start the biogas slurry hot water decoupling ammonia removal system and its electrical control device. The PID control unit compares the data obtained from the probe with the threshold and controls the start and stop of the slurry screw feed pump, hot water decoupling feed pump, and valves to coordinate the reaction progress in the slurry reactor, hot water decoupling reactor, and flash separator, thereby achieving efficient operation of the biogas slurry hot water decoupling ammonia removal system. Figure 3 As shown, the dashed line indicates that the start and stop of the device at the arrow end are determined and controlled based on the data obtained from the probe inside the device at the starting end of the line.

[0051] Specifically:

[0052] When the liquid level in the slurry reactor is below the low threshold, the slurry screw feed pump is started; when the liquid level in the slurry reactor is above the high threshold, the slurry screw feed pump is shut down.

[0053] When the liquid level or temperature in the slurry reactor is below the low threshold, the over-steam reflux valve is opened; when the liquid level or temperature in the slurry reactor is above the high threshold, the over-steam reflux valve is closed.

[0054] The steam regulating valve is opened when the pressure inside the hot hydrolysis reactor is below the low threshold, and closed when the pressure inside the hot hydrolysis reactor is above the high threshold.

[0055] The hot water hydrolysis feed pump is activated when the liquid level in the slurry reactor or the temperature in the hot water hydrolysis reactor exceeds the high threshold, and activated when the liquid level in the slurry reactor or the temperature in the hot water hydrolysis reactor falls below the low threshold. Simultaneously, the hot water hydrolysis feed pump is also activated when the liquid level in the flash separator falls below the low threshold, and shut down when the liquid level in the flash separator rises above the high threshold. This allows the reaction state within the hot water hydrolysis reactor to be adjusted promptly according to the reaction progress in both the slurry reactor and the flash separator, forming a coupling between biogas slurry hot water hydrolysis and ammonia removal, which helps maintain system stability.

[0056] When the difference between the flash separator and the hot water hydrolysis reactor is below the low threshold, the electric switching valve is opened; when the difference between the flash separator and the hot water hydrolysis reactor is above the high threshold, the electric switching valve is shut off.

[0057] At the same time, the electric switch valve is opened when the liquid level in the flash separator is lower than the low threshold value, and the electric switch valve is closed when the liquid level in the flash separator is higher than the high threshold value. Further strengthen the coupling of ammonia removal and thermal hydrolysis process, improve the working efficiency of the flash separator.

[0058] During operation, the operation data of the biogas slurry thermal hydrolysis coupled ammonia removal system is uploaded to the user end for real-time analysis, monitoring and storage. When the feedback information display device of the frequency converter fails, etc., the electric circuit is cut off through the emergency stop button.

Claims

1. A control method for an electrical control device used in a biogas slurry hot water decoupling and ammonia removal system, characterized in that, The electrical control device for the biogas slurry hot water decoupling ammonia removal system includes: a power supply, which is connected in parallel to a slurry reactor, a hot water decoupling reactor, a slurry screw feed pump, a hot water decoupling feed pump, a PLC and valve power supply, a control power supply and a DC switching power supply, and each parallel branch is equipped with a circuit breaker, and the power supply is also equipped with a circuit breaker. The slurry reactor is equipped with a level probe and a temperature probe, the hot water hydrolysis reactor is equipped with a temperature probe and a pressure sensor probe, and the flash separator is equipped with a level probe and a pressure sensor probe. The valves include an electrically operated on / off valve leading from the hot hydrolysis reactor to the flash separator, a steam reflux valve leading from the flash separator to the slurry reactor, and a steam regulating valve leading to the hot hydrolysis reactor; the valves are connected in parallel in the branches of the PLC and valve power supply, and each branch of the valve is equipped with a circuit breaker. All probes are connected to the input card of the PLC, and the slurry screw feed pump, hot water hydrolysis feed pump and all valves are connected to the output card of the PLC. The PLC includes a PID control unit for automatic adjustment. The control method for this electrical control device used in a biogas slurry hot water decoupling ammonia removal system includes the following steps: Step 1: Install the electrical control device for the biogas slurry hot water decoupling ammonia removal system at the biogas slurry hot water decoupling ammonia removal system and connect it to the power supply; Step 2: Connect the level probe and temperature probe in the slurry reactor, the temperature probe and pressure sensor probe in the hot hydrolysis reactor, and the level probe and pressure sensor probe in the flash separator to the PLC input / output card in the electrical control device, and set the high and low threshold values ​​for the corresponding data of each probe and the high and low threshold values ​​for the pressure difference in the flash separator and the hot hydrolysis reactor in the PID control unit. Step 3: Power on the main incoming line switch in the electrical control device, then close the control power switch, and finally close the power switch of the process equipment. Check the display status of each indicator light and enter the pre-start stage. Step 4: Start the biogas slurry hot water decoupling ammonia removal system and its electrical control device. The PID control unit compares the data obtained from the probe with the threshold and controls the start and stop of the slurry screw feed pump, the hot water decoupling feed pump and the valves. When the liquid level in the slurry reactor or the temperature in the hot water decoupling reactor is higher than the high threshold, the hot water decoupling feed pump is turned on. When the liquid level in the slurry reactor or the temperature in the hot water decoupling reactor is lower than the low threshold, the hot water decoupling feed pump is turned off. At the same time, the hot water hydrolysis feed pump is turned on when the liquid level in the flash separator is lower than the low threshold, and the hot water hydrolysis feed pump is turned off when the liquid level in the flash separator is higher than the high threshold. When the pressure difference between the flash separator and the hot water hydrolysis reactor is lower than the low threshold, the electric switch valve is opened; when the pressure difference between the flash separator and the hot water hydrolysis reactor is higher than the high threshold, the electric switch valve is closed. At the same time, the electric switching valve is opened when the liquid level in the flash separator is lower than the low threshold, and closed when the liquid level in the flash separator is higher than the high threshold.

2. The control method for the electrical control device of the biogas slurry hot water decoupling ammonia removal system according to claim 1, characterized in that, The slurry screw feed pump is located in the feed pipe of the slurry reactor, and the hot hydrolysis feed pump is located in the pipe leading from the slurry reactor to the hot hydrolysis feed pump.

3. The control method for the electrical control device of the biogas slurry hot water decoupling ammonia removal system according to claim 1, characterized in that, A frequency converter is installed on each of the parallel branches where the slurry reactor, the hot water hydrolysis reactor, the slurry screw feed pump, and the hot water hydrolysis feed pump are located.

4. The control method for the electrical control device of the biogas slurry hot water decoupling ammonia removal system according to claim 1, characterized in that, The parallel branch where the slurry reactor is located also has a slurry reactor fan connected in parallel, the parallel branch where the hot hydrolysis reactor is located also has a slurry reactor fan connected in parallel, and the parallel branch where the slurry screw feed pump is located also has a slurry screw feed pump fan connected in parallel; and each branch where the slurry reactor fan, the slurry reactor fan, and the slurry screw feed pump fan are located is equipped with a circuit breaker.

5. The control method for the electrical control device of the biogas slurry hot water decoupling and ammonia removal system according to claim 1, characterized in that, In step four: When the liquid level in the slurry reactor is below the low threshold, the slurry screw feed pump is started; when the liquid level in the slurry reactor is above the high threshold, the slurry screw feed pump is shut down. When the liquid level or temperature in the slurry reactor is below the low threshold, the over-steam reflux valve is opened; when the liquid level or temperature in the slurry reactor is above the high threshold, the over-steam reflux valve is closed. The steam regulating valve is opened when the pressure inside the hot hydrolysis reactor is below the low threshold, and closed when the pressure inside the hot hydrolysis reactor is above the high threshold.

6. The control method for the electrical control device of the biogas slurry hot water decoupling ammonia removal system according to claim 1, characterized in that, During operation, the operating data of the biogas slurry hot water decoupling ammonia removal system is uploaded to the user terminal for real-time analysis, monitoring and storage.

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