Control system for air floating type water treatment system of marine dual-fuel engine

Abstract

The invention provides a control system of an air floating type water treatment system for a marine dual-fuel engine, and also provides a corresponding control method, computer control equipment and a computer readable storage medium. According to the system, through a processor module, a digital quantity input module, a digital quantity output module, an analog quantity input module and an analog quantity output module which are integrated on a PLC (Programmable Logic Controller), air flotation and the filling quantity of a PAC (Poly Aluminum Chloride) agent and alkali liquor are controlled, the oil content in wastewater is reduced, and automatic start and stop are realized according to high and low liquid level signals of a wastewater storage tank; the pH value of the wastewater is controlled within a certain range through PID control, and the dosage of PAC, the deslagging of a precipitation cabinet, the flow of a discharge pump, the backwashing of a sand filter and the like are controlled. The influence caused by shaking is reduced, and meanwhile the forced deslagging effect is achieved; the flushing efficiency is greatly improved, sediment is discharged into the sediment cabinet, and clear water returns to the discharging cabinet; and the pH control precision is improved.

Description

Technical Field

[0001] The present invention relates to water treatment system technology in the field of energy conservation and environmental protection technology, and in particular to a control system for an air-floating water treatment system for a marine dual-fuel engine, and also to a corresponding control method, a computer control device and a computer-readable storage medium. Background Art

[0002] Marine dual-fuel engines are limited by the reactivity of fuel gas and are forced to use a lower compression ratio, but this will result in low thermal efficiency in diesel mode. However, due to structural and strength limitations of low-speed engines, variable compression ratio technology is still immature, so controlling the oxygen concentration in the scavenging gas to avoid premature combustion of fuel gas has become the main solution. Using an intelligent exhaust gas recirculation system, part of the exhaust gas generated by the engine is washed and cooled, and then introduced into the compressor of the main engine turbocharger and mixed with fresh air to achieve oxygen concentration control of the scavenging gas. However, the oil content in the wastewater after washing increases and cannot reach below 15ppm, which cannot meet the requirements for marine wastewater discharge. Therefore, an air flotation water treatment system is required to treat the wastewater after washing to reduce the oil content in the wastewater to less than 15ppm to meet the relevant requirements of IMO regulations MPEC 307 (73).

[0003] However, the direct application of the air flotation water treatment system in marine dual-fuel engines usually has the following technical problems: a large amount of clean water is required for filter media backwashing, and the fresh water on board cannot be consumed to complete the backwashing. The wastewater after backwashing is between slag and wastewater. Discharging it into the slag tank will increase the slag discharge rate. If it is discharged into the wastewater tank, it will pollute the raw water. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a control system for an air-floating water treatment system for a marine dual-fuel engine, and also provides a corresponding control method, a computer control device and a computer-readable storage medium.

[0005] According to one aspect of the present invention, there is provided a control system for an air-floating water treatment system for a marine dual-fuel engine, comprising:

[0006] Digital input module, which is used to process input digital signals, including: supply pump overload, reflux pump overload, backwash pump overload, discharge pump overload, bypass switching valve RV1 position feedback, super pH reflux valve RV2 position feedback, forced slag discharge valve RV3 position feedback, dissolved air valve RV4 position feedback, backwash water buffer valve RV6 position feedback, backwash pump outlet valve RV7 position feedback, concentrated slag discharge valve RV10 position feedback, clear water discharge valve RV11 position feedback, dissolved air tank liquid level LS1 feedback, sand filter high liquid level LS2 feedback, sand filter low liquid level LS3 feedback, clear water buffer low liquid level LS4 feedback, sewage buffer high liquid level LS5 feedback and PAC cabinet low level alarm LS6 feedback;

[0007] Digital output module, which is used to process output digital signals, including: supply pump start, reflux pump start, backwash pump start, discharge pump start, bypass switching valve RV1 open, super pH reflux valve RV2 open, forced slag discharge valve RV3 closed, dissolved air valve RV4 open, booster pump outlet regulating valve RV5 open, booster pump outlet regulating valve RV5 closed, backwash water buffer valve RV6 open, backwash pump outlet valve RV7 open, sand filter backwash solenoid valve RV9 open, concentrated slag discharge valve RV10 open, and clean water discharge valve RV11 open;

[0008] Analog input module, which is used to process input analog signals, including: booster pump outlet regulating valve RV5 position feedback, pH feedback before neutralization, pH feedback after neutralization, inlet wastewater flow feedback, outlet wastewater flow feedback and sedimentation tank turbidity feedback;

[0009] Analog output module, which is used to process the output analog signals, including: alkali liquid pump flow control and PAC dosing pump flow control;

[0010] A processor module, which includes an operating system unit for storing system programs and a user operation unit for storing user programs; wherein the operating system unit is used to process the startup of the above modules and refresh the process image input area and output area; the user operation unit is used to control the above modules to perform automation control tasks.

[0011] Preferably, the digital input module and the digital output module are in standby state, and control the tasks according to the bypass operation mode output by the processor module. When the bypass operation mode is activated, the bypass switching valve RV1 is locked to the closed position, and the oil meter inlet is directly bypassed; when the system is operated manually or automatically, the system enters the bypass operation state, controls the supply pump SP to operate, and executes the bypass operation mode.

[0012] Preferably, when the control system is started, the digital input module and the digital output module open the dissolved air valve RV4 and run the reflux pump according to the flotation operation mode control task output by the processor module; when the dissolved air pump is running, the container tank liquid level LS1 control is activated. When the dissolved air tank liquid level LS1 is activated, it is a high liquid level, and the solenoid valve RV8 is opened after a delay of a set time t1. After the dissolved air tank liquid level LS1 returns to a low liquid level state, the solenoid valve RV8 is closed after a delay of a set time t1 to execute the front flotation operation mode of the flotation operation mode control task.

[0013] 4. The control system of the air flotation water treatment system for a marine dual-fuel engine according to claim 1 is characterized in that when the control system is started, the digital input module and the digital output module, according to the air flotation operation mode control task output by the processor module, after the dissolved air pump runs for a set time t2, open the bypass switching valve RV1, start the supply pump SP, and execute the supply pump operation mode of the air flotation operation mode control task.

[0014] Preferably, when the control system is started, the analog input module and the analog output module, according to the flotation operation mode control task output by the processor module, turn on the alkali solution control when the supply pump SP is running, and according to the value of pH1, look up the table to determine the concentration of alkali solution to be added, and within a certain deviation range of the added concentration, perform closed-loop PI adjustment according to the value of pH2, and then multiply it by the flow value of FT1, calculate and control the injection frequency of the alkali solution pump, and execute the alkali solution neutralization control of the flotation operation mode control task.

[0015] Preferably, when the control system is started, the analog input module and the analog output module control the flotation operation mode task output by the processor module. When the ultra-pH reflux valve RV2 is opened, the PAC dosing pump is controlled according to the set PAC concentration, multiplied by the flow value of FT1, and combined with the chemical pump parameters to execute the PAC dosing control of the flotation operation mode control task.

[0016] Preferably, when the control system is started, the digital input module and the digital output module, according to the flotation operation mode control task output by the processor module, start the control countdown t3 of the sedimentation tank slag discharge after the supply pump SP is running and the super-pH reflux valve RV2 is opened. After the countdown ends, a turbidity meter scraping operation is performed. After the water flow stabilizes, the turbidity value of the slag tank is checked. If the value is greater than the set threshold N, the sedimentation tank slag discharge valve RV12 is opened and maintained for the set time t420 seconds, and then the timing of the sedimentation tank slag discharge valve RV12 is reset; after the turbidity check and slag discharge of the sedimentation tank are completed, the forced slag discharge valve RV3 is closed, and the forced slag discharge valve RV3 is opened for the set time t5 to execute the sedimentation tank slag discharge control of the flotation operation mode control task.

[0017] Preferably, when the control system is started up, the digital input module and the digital output module, according to the air flotation operation mode control task output by the processor module, when the water supply pump is running and the high level LS2 of the sand filter is activated, open the regulating valve RV5 at the outlet of the booster pump to the set opening o, and start the discharge pump DP; the initial target value of FT2 is FT1; when the high level LS2 of the sand filter is activated at a high level, the target value of FT2 increases by X% per minute; when the low level LS3 of the sand filter is activated at a low level, the target value of FT2 decreases by x% per minute; when neither the high level LS2 nor the low level LS3 of the sand filter is activated, the target value of FT2 changes by y% per minute until it is equal to FT1; the regulating valve RV5 at the outlet of the booster pump takes the difference between FT2 and FT1, multiplies it by the value of the coefficient P as the target change value of the opening of the regulating valve RV5 at the outlet of the booster pump. If FT2 - FT1 < FT2 and the maximum deviation difference between FT2 and FT1 is 0, the regulating valve RV5 at the outlet of the booster pump is not adjusted, and the discharge pump flow control of the air flotation operation mode control task is executed.

[0018] Preferably, when the control system is started up, the digital input module and the digital output module, according to the air flotation operation mode control task output by the processor module, when the discharge pump DP is running, start the countdown of the backwashing program. After the countdown ends, check whether the countdown of the concentrated slag discharge valve RV10 has ended. If it has not ended, wait for it to end. If it has ended, open the concentrated slag discharge valve RV10 and keep it open for the set time t6, then close the concentrated slag discharge valve RV10, open the clear water discharge valve RV11 and keep it open for the set time t7, and then close the clear water discharge valve RV11; after the clear water discharge valve RV11 is closed, open the outlet valve RV7 of the backwashing pump, then open the sand filter backwashing solenoid valve RV9, keep the backwashing water buffer valve RV6 open for the set time t8, then start the backwashing pump, keep it running for the set time t9, stop the backwashing pump, and close the outlet valve RV7 of the backwashing pump and the backwashing water buffer valve RV6 to execute the sand filter backwashing control of the air flotation operation mode control task; during the sand filter backwashing control, if the low level LS4 of the clear water buffer or the high level LS5 of the sewage buffer is activated, the sand filter backwashing control process is ended in advance.

[0019] Preferably, when the low level of the waste water storage tank is triggered, the digital input module and the digital output module, according to the shutdown mode control task output by the processor module, start the shutdown program, stop the supply pump SP, close the ultra-pH reflux valve RV2, and the PAC chemical pump will automatically stop according to the position of the ultra-pH reflux valve RV2 and the flow rate of FT1, and close the bypass switching valve RV1;

[0020] When the water supply pump SP stops, the digital input module and the digital output module execute the post-shutdown flotation control task output by the processor module to close the forced slag discharge valve RV3 once, then open the forced slag discharge valve RV3, stop the reflux pump, and close the dissolved air valve RV4; if the sand filter low liquid level LS3 is triggered, stop the discharge pump DP and close the booster pump outlet regulating valve RV5;

[0021] When the discharge pump DP and the dissolved air pump RV4 stop, the digital input module and the digital output module check whether the countdown of the concentrated slag discharge valve RV10 is over according to the shutdown backwash control task output by the processor module. If so, perform a sand filter backwash and then end the shutdown mode; otherwise, directly stop the shutdown mode.

[0022] In some preferred embodiments, the processor module, digital input module, digital output module, analog input module and analog output module are integrated on a PLC controller.

[0023] According to a second aspect of the present invention, a control method for an air-floating water treatment system for a marine dual-fuel engine is provided, characterized in that a control system for an air-floating water treatment system for a marine dual-fuel engine described in any one of the above-mentioned aspects of the present invention is used to control a bypass operation mode, an air-floating operation mode and a shutdown mode of the air-floating water treatment system for a marine dual-fuel engine.

[0024] According to a third aspect of the present invention, there is provided a computer control device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor can be used to execute any one of the above-mentioned systems of the present invention when executing the computer program.

[0025] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, can be used to run any of the above-mentioned systems of the present invention.

[0026] Due to the adoption of the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0027] The control system of the air flotation water treatment system for a marine dual-fuel engine provided by the present invention adopts an air-water combined backwashing and a backwash clean water / wastewater buffer discharge mode, firstly uses compressed air to backwash to loosen the filter material, and then uses a small amount of clean water for backwashing, which will greatly improve the flushing efficiency; the backwashing water comes from the primary treated water after air flotation filtration, and is buffered before entering the sand filter. After the wastewater after backwashing is left to stand in the wastewater buffer cabinet for a period of time, the sediment is discharged into the slag cabinet, and the clean water returns to the discharge cabinet.

[0028] The control system of the air-floating water treatment system for a marine dual-fuel engine provided by the present invention adopts an open-loop plus closed-loop method to control pH, thereby significantly improving pH control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0030] Figure 1 It is a schematic diagram of the working principle of a control system of an air-floating water treatment system for a marine dual-fuel engine in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is a detailed description of the embodiments of the present invention: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0032] An embodiment of the present invention provides a control system for an air flotation water treatment system for a marine dual-fuel engine. The system is based on a PLC and receives high and low liquid level signals from a washing wastewater storage tank to realize start and stop control of the water treatment system, including air flotation control at startup, wastewater supply pump control, alkali solution neutralization and PAC dosing control, sedimentation tank slag discharge control, discharge pump flow control, sand filter backwash control, and air flotation control after shutdown.

[0033] Specifically, Figure 1 As shown, the control system of the air-floating water treatment system for a marine dual-fuel engine provided in this embodiment may include the following modules:

[0034] A processor (CPU) module, which includes an operating system unit for storing system programs and a user operation unit for storing user programs; wherein the operating system unit is used to process the startup of the following modules and refresh the process image input area and output area, etc.; the user operation unit is used to control the following modules to perform corresponding automation control tasks, etc.;

[0035] Digital input module, which is used to process input digital signals, including: supply pump overload, reflux pump overload, backwash pump overload, discharge pump overload, bypass switching valve RV1 position feedback, super pH reflux valve RV2 position feedback, forced slag discharge valve RV3 position feedback, dissolved air valve RV4 position feedback, backwash water buffer valve RV6 position feedback, backwash pump outlet valve RV7 position feedback, concentrated slag discharge valve RV10 position feedback, clear water discharge valve RV11 position feedback, dissolved air tank liquid level LS11 feedback, sand filter high liquid level LS21 feedback, sand filter low liquid level LS31 feedback, clear water buffer low liquid level LS41 feedback, sewage buffer high liquid level LS51 feedback and PAC cabinet low level alarm LS61 feedback;

[0036] Digital output module, which is used to process output digital signals, including: supply pump start, reflux pump start, backwash pump start, discharge pump start, bypass switching valve RV1 open, super pH reflux valve RV2 open, forced slag discharge valve RV3 closed, dissolved air valve RV4 open, booster pump outlet regulating valve RV5 open, booster pump outlet regulating valve RV5 closed, backwash water buffer valve RV6 open, backwash pump outlet valve RV7 open, sand filter backwash solenoid valve RV9 open, concentrated slag discharge valve RV10 open, and clean water discharge valve RV11 open;

[0037] Analog input module, which is used to process input analog signals, including: booster pump outlet regulating valve RV5 position feedback, pH feedback before neutralization, pH feedback after neutralization, inlet wastewater flow feedback, outlet wastewater flow feedback and sedimentation tank turbidity feedback;

[0038] Analog output module, which is used to process the output analog signals, including: alkali liquid pump flow control and PAC dosing pump flow control.

[0039] Furthermore, in the above embodiment:

[0040] The digital input module processes the input digital signal, specifically: converting the external digital passive contact signal into 0 or 1 that can be recognized by the program, that is, contact closed = 1, contact open = 0.

[0041] The digital output module processes the output digital signal, specifically: converting the start / stop, open / close (1 / 0) instructions in the program into passive contact output, that is, 1 = contact closed, 0 = contact open.

[0042] The analog input module processes the input analog signal, specifically: converting the external 4-20mA current signal into the measurement engineering value of the sensor.

[0043] The analog output module processes the output analog signal, specifically: converting the engineering value of the analog quantity in the program into a 4-20mA current signal.

[0044] The control system of the air-floating water treatment system for a marine dual-fuel engine provided by the above embodiment of the present invention mainly realizes the following functions:

[0045] 1. Bypass operation mode.

[0046] 2. Air flotation operation mode, including:

[0047] 1. Front air flotation operation mode;

[0048] 2. Supply pump operation mode;

[0049] 3. Alkali neutralization control mode;

[0050] 4. PAC dosing control mode;

[0051] 5. Sedimentation tank slag discharge control mode;

[0052] 6. Discharge pump flow control mode;

[0053] 7. Sand filter backwash control mode.

[0054] 3. Shutdown mode, including:

[0055] 1. Air flotation control mode after shutdown;

[0056] 2. Shutdown backwash control mode.

[0057] In some preferred embodiments, the digital input module and the digital output module are in standby state, and control the tasks according to the bypass operation mode output by the processor module. When the bypass operation mode is activated, the bypass switching valve RV1 is locked to the closed position, and the oil meter inlet is directly bypassed; when the system is operated manually or automatically, the system enters the bypass operation state, controls the supply pump SP to operate, and executes the bypass operation mode.

[0058] In some preferred embodiments, when the control system is started, the digital input module and the digital output module open the dissolved air valve RV4 and run the reflux pump according to the flotation operation mode control task output by the processor module; when the dissolved air pump is running, the container tank liquid level LS1 control is activated. When the dissolved air tank liquid level LS1 is activated, it is a high liquid level, and the solenoid valve RV8 is opened after a delay of a set time t1. After the dissolved air tank liquid level LS1 returns to a low liquid level state, the solenoid valve RV8 is closed after a delay of a set time t1, and the front flotation operation mode of the flotation operation mode control task is executed.

[0059] In some preferred embodiments, t1 is preferably 10 seconds.

[0060] In some preferred embodiments, when the control system is started, the digital input module and the digital output module, according to the flotation operation mode control task output by the processor module, after the dissolved air pump runs for the set time t2, open the bypass switching valve RV1, start the supply pump SP, and execute the supply pump operation mode of the flotation operation mode control task.

[0061] In some preferred embodiments, t2 is preferably 30 seconds.

[0062] In some preferred embodiments, when the control system is started, the analog input module and the analog output module, according to the flotation operation mode control task output by the processor module, start the alkali solution control (pH1 open loop + pH2 closed loop) when the supply pump SP is running, and according to the value of pH1, look up the table to determine the concentration of alkali solution to be added, and within a certain deviation range of the added concentration, perform closed-loop PI adjustment according to the value of pH2, and then multiply it by the flow value of FT1, calculate and control the injection frequency of the alkali solution pump, and execute the alkali solution neutralization control of the flotation operation mode control task.

[0063] In some preferred embodiments, when the control system is started, the analog input module and the analog output module control the flotation operation mode task output by the processor module. When the ultra-pH reflux valve RV2 is opened, the PAC dosing pump is controlled according to the set PAC concentration, multiplied by the flow value of FT1, and combined with the chemical pump parameters to execute the PAC dosing control of the flotation operation mode control task.

[0064] In some preferred embodiments, when the control system is started, the digital input module and the digital output module, according to the flotation operation mode control task output by the processor module, start the control countdown t3 of the sedimentation tank slag discharge after the supply pump SP is running and the ultra-pH reflux valve RV2 is opened. After the countdown ends, a turbidity meter scraping operation is performed. After the water flow stabilizes, the turbidity value of the slag tank is checked. If the value is greater than the set threshold N, the sedimentation tank slag discharge valve RV12 is opened and maintained for the set time t420 seconds, and then the timing of the sedimentation tank slag discharge valve RV12 is reset; after the turbidity check and slag discharge of the sedimentation tank are completed, the forced slag discharge valve RV3 is closed, and the forced slag discharge valve RV3 is opened for the set time t5 to execute the sedimentation tank slag discharge control of the flotation operation mode control task.

[0065] In some preferred embodiments, t3 is preferably 60 seconds.

[0066] In some preferred embodiments, the threshold N is preferably set to 500 NTU.

[0067] In some preferred embodiments, t4 is preferably 20 seconds.

[0068] In some preferred embodiments, t5 is preferably 120 seconds.

[0069] In some preferred embodiments, when the control system starts up, the digital input module and the digital output module, according to the air flotation operation mode control task output by the processor module, when the water supply pump is running and the high level LS2 of the sand filter is activated, open the pressure increasing pump outlet regulating valve RV5 to the set opening o, and start the discharge pump DP; the initial target value of FT2 is FT1; when the high level LS2 of the sand filter is activated at a high level, the target value of FT2 increases by X% per minute; when the low level LS3 of the sand filter is activated at a low level, the target value of FT2 decreases by x% per minute; when neither the high level LS2 nor the low level LS3 of the sand filter is activated, the target value of FT2 changes by y% per minute until it is equal to FT1; the pressure increasing pump outlet regulating valve RV5 takes the difference between FT2 and FT1, multiplies it by the value of the coefficient P as the opening target change value of the pressure increasing pump outlet regulating valve RV5. If FT2 - FT1 < FT2 and the maximum deviation difference between FT2 and FT1 is 0, the pressure increasing pump outlet regulating valve RV5 is not adjusted, and the discharge pump flow control of the air flotation operation mode control task is executed.

[0070] In some preferred embodiments, the set opening o is preferably 50%.

[0071] In some preferred embodiments, when the control system starts up, the digital input module and the digital output module, according to the air flotation operation mode control task output by the processor module, when the discharge pump DP is running, start the countdown of the backwashing program. After the countdown ends, check whether the countdown of the concentrated slag discharge valve RV10 has ended. If it has not ended, wait until it ends. If it has ended, open the concentrated slag discharge valve RV10 and keep it open for the set time t6, then close the concentrated slag discharge valve RV10, open the clear water discharge valve RV11, and keep it open for the set time t7, then close the clear water discharge valve RV11; after the clear water discharge valve RV11 is closed, open the backwashing pump outlet valve RV7, then open the sand filter backwashing solenoid valve RV9, keep the backwashing water buffer valve RV6 open for the set time t8, then start the backwashing pump, keep it running for the set time t9, stop the backwashing pump, and close the backwashing pump outlet valve RV7 and the backwashing water buffer valve RV6, and execute the sand filter backwashing control of the air flotation operation mode control task; during the sand filter backwashing control, if the low level LS4 of the clear water buffer or the high level LS5 of the sewage buffer is activated, the sand filter backwashing control process is ended in advance. Through this sand filter backwashing process, the problem that a large amount of clear water is required for filter media backwashing, the fresh water on the ship cannot be consumed to complete the backwashing, the waste water after backwashing is between slag and waste water, discharging it into the slag tank will increase the slag discharge rate, and if it is discharged into the waste water tank, it will pollute the raw water is solved. The backwashing is realized with a small amount of clear water, the washing efficiency is improved, the sediment is discharged into the slag tank, and the clear water returns to the drain tank, avoiding the pollution of the raw water.

[0072] In some preferred embodiments, t6 is preferably 20 seconds.

[0073] In some preferred embodiments, t7 is preferably 40 seconds.

[0074] In some preferred embodiments, t8 is preferably 30 seconds.

[0075] In some preferred embodiments, t9 is preferably 10 minutes.

[0076] In some preferred embodiments, when the low liquid level in the wastewater storage tank is triggered, the digital input module and the digital output module start the shutdown procedure according to the shutdown mode control task output by the processor module, stop the supply pump SP, close the ultra-pH reflux valve RV2, and the PAC agent pump will automatically stop according to the position of the ultra-pH reflux valve RV2 and the flow rate of FT1, and close the bypass switching valve RV1.

[0077] In some preferred embodiments, when the water supply pump SP stops, the digital input module and the digital output module execute the post-shutdown flotation control task output by the processor module, close the forced slag discharge valve RV3 once, then open the forced slag discharge valve RV3, stop the reflux pump, and close the dissolved air valve RV4; if the sand filter low liquid level LS3 is triggered, stop the discharge pump DP and close the boost pump outlet regulating valve RV5.

[0078] In some preferred embodiments, when the discharge pump DP and the dissolved air pump RV4 stop, the digital input module and the digital output module check whether the countdown of the concentrated slag discharge valve RV10 is over according to the shutdown backwash control task output by the processor module. If so, perform a sand filter backwash and then end the shutdown mode; otherwise, directly stop the shutdown mode.

[0079] In some preferred embodiments, the processor module, digital input module, digital output module, analog input module and analog output module are integrated on a PLC controller.

[0080] In some preferred implementations, the PLC controller is S7-1200 PLC.

[0081] Based on the same inventive concept, an embodiment of the present invention also provides a control method for an air-floating water treatment system for a marine dual-fuel engine. The method adopts the control system of the air-floating water treatment system for a marine dual-fuel engine described in any one of the above embodiments of the present invention to control the bypass operation mode, air-floating operation mode and shutdown mode of the air-floating water treatment system for a marine dual-fuel engine.

[0082] It should be noted that the steps in the method provided by the present invention can be implemented by using corresponding modules, devices, units, etc. in the system. Those skilled in the art can refer to the technical solution of the system to implement the step flow of the method, that is, the embodiments in the system can be understood as preferred examples of implementing the method, which will not be elaborated here.

[0083] The control system of the air-floating water treatment system for a marine dual-fuel engine provided by the above embodiment of the present invention is based on PLC and realizes 1. Liquid level control: receiving the high and low liquid level switch sensor signals of the wastewater storage tank to realize two modes: high and low liquid level start and stop and low liquid level maintenance; 2. The system status is divided into standby, air-floating operation, air-floating stop, fault, bypass, bypass operation; 3. Bypass operation mode control; 4. Air-floating operation mode control; 5. Stop mode and fast stop mode control; 6. The system issues an alarm when the system status measurement value exceeds the preset value. The above are the preferred embodiments of the present invention. For those skilled in the art, any obvious equivalent or equivalent changes made thereto without departing from the principle and spirit of the present invention should be deemed to be included in the protection scope of the claims of the present invention.

[0084] An embodiment of the present invention further provides a computer control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it can be used to run the system described in any one of the above embodiments of the present invention.

[0085] Optionally, the memory is used to store programs; the memory may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviated: RAM), such as static random-access memory (English: static random-access memory, abbreviated: SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviated: DDR SDRAM), etc.; the memory may also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory is used to store computer programs (such as applications, functional modules, etc. that implement the above method), computer instructions, etc., and the above computer programs, computer instructions, etc. can be partitioned and stored in one or more memories. And the above computer programs, computer instructions, data, etc. can be called by the processor.

[0086] The above-mentioned computer programs, computer instructions, etc. may be stored in one or more memories in partitions, and the above-mentioned computer programs, computer instructions, data, etc. may be called by a processor.

[0087] The processor is used to execute the computer program stored in the memory to implement the various steps of the method or various modules of the system involved in the above embodiments. For details, please refer to the relevant descriptions in the above method and system embodiments.

[0088] The processor and the memory may be independent structures or integrated structures. When the processor and the memory are independent structures, the memory and the processor may be coupled and connected via a bus.

[0089] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it can be used to run the system described in any one of the above embodiments of the present invention.

[0090] Among them, computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general or special-purpose computer. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a user device. Of course, the processor and the storage medium can also be present in a communication device as discrete components.

[0091] The control system of the air flotation water treatment system for a marine dual-fuel engine provided by the above embodiment of the present invention preferably adopts the S7-1200 series PLC as a controller, and reduces the oil content in the wastewater by controlling the air flotation and the amount of PAC agent / alkali solution added. Automatic start and stop are realized according to the high and low liquid level signals of the wastewater storage tank, and the pH of the wastewater is controlled within a certain range through PID control, and the PAC dosage, sedimentation tank slag discharge, discharge pump flow, sand filter backwashing, etc. are controlled.

[0092] All matters not covered in the above embodiments of the present invention are well known in the art.

[0093] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A control system for an air-floating water treatment system for a marine dual-fuel engine, characterized in that: include: Digital input module, which is used to process input digital signals, including: supply pump overload, reflux pump overload, backwash pump overload, discharge pump overload, bypass switching valve RV1 position feedback, super pH reflux valve RV2 position feedback, forced slag discharge valve RV3 position feedback, dissolved air valve RV4 position feedback, backwash water buffer valve RV6 position feedback, backwash pump outlet valve RV7 position feedback, concentrated slag discharge valve RV10 position feedback, clear water discharge valve RV11 position feedback, dissolved air tank liquid level LS1 feedback, sand filter high liquid level LS2 feedback, sand filter low liquid level LS3 feedback, clear water buffer low liquid level LS4 feedback, sewage buffer high liquid level LS5 feedback and PAC cabinet low level alarm LS6 feedback; Digital output module, which is used to process output digital signals, including: supply pump start, reflux pump start, backwash pump start, discharge pump start, bypass switching valve RV1 open, super pH reflux valve RV2 open, forced slag discharge valve RV3 closed, dissolved air valve RV4 open, booster pump outlet regulating valve RV5 open, booster pump outlet regulating valve RV5 closed, backwash water buffer valve RV6 open, backwash pump outlet valve RV7 open, sand filter backwash solenoid valve RV9 open, concentrated slag discharge valve RV10 open, and clean water discharge valve RV11 open; Analog input module, which is used to process input analog signals, including: booster pump outlet regulating valve RV5 position feedback, pH feedback before neutralization, pH feedback after neutralization, inlet wastewater flow feedback, outlet wastewater flow feedback and sedimentation tank turbidity feedback; Analog output module, which is used to process the output analog signals, including: alkali liquid pump flow control and PAC dosing pump flow control; A processor module, which includes an operating system unit for storing system programs and a user operation unit for storing user programs; wherein the operating system unit is used to process the startup of the above modules and refresh the process image input area and output area; the user operation unit is used to control the above modules to perform automation control tasks.

2. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: The digital input module and the digital output module are in standby state, and control the tasks according to the bypass operation mode output by the processor module. When the bypass operation mode is activated, the bypass switching valve RV1 is locked to the closed position, and the oil meter inlet is directly bypassed; when the system is operated manually or automatically, the system enters the bypass operation state, controls the supply pump SP to operate, and executes the bypass operation mode.

3. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system is started, the digital input module and the digital output module open the dissolved air valve RV4 and run the reflux pump according to the flotation operation mode control task output by the processor module; when the dissolved air pump is running, the container tank liquid level LS1 control is activated. When the dissolved air tank liquid level LS1 is activated, it is a high liquid level, and the solenoid valve RV8 is opened after a delay of a set time t1. After the dissolved air tank liquid level LS1 returns to a low liquid level state, the solenoid valve RV8 is closed after a delay of a set time t1, and the front flotation operation mode of the flotation operation mode control task is executed.

4. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system starts, the digital input module and the digital output module, according to the dissolved air flotation operation mode control task output by the processor module, after the dissolved air pump runs for a set time t2, open the bypass switching valve RV1, start the supply pump SP, and execute the supply pump operation mode of the dissolved air flotation operation mode control task.

5. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system starts, the analog input module and the analog output module, according to the dissolved air flotation operation mode control task output by the processor module, when the supply pump SP is running, start the lye control. According to the value of pH1, look up the table to determine the concentration of lye to be added. Within a certain deviation range of the added concentration, perform closed-loop PI regulation according to the value of pH2, then multiply by the flow value of FT1, calculate and control the injection frequency of the lye pump, and execute the lye neutralization control of the dissolved air flotation operation mode control task.

6. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system starts, the analog input module and the analog output module, according to the dissolved air flotation operation mode control task output by the processor module, when the over-pH reflux valve RV2 is opened, multiply the set PAC concentration by the flow value of FT1, and control the PAC dosing pump in combination with the chemical dosing pump parameters to execute the PAC dosing control of the dissolved air flotation operation mode control task.

7. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system starts, the digital input module and the digital output module, according to the dissolved air flotation operation mode control task output by the processor module, when the supply pump SP is running and the over-pH reflux valve RV2 is opened, start the control countdown t3 for sedimentation tank slag discharge. After the countdown ends, perform a turbidity meter slag scraping operation once. After the water flow stabilizes, check the turbidity value of the slag tank. If the value is greater than the set threshold N, open the sedimentation tank slag discharge valve RV12 and keep it for the set time t4 (20 seconds), then reset the timing of the sedimentation tank slag discharge valve RV12; after the sedimentation tank turbidity inspection and slag discharge are completed, close the forced slag discharge valve RV3, keep it for the set time t5, and then open the forced slag discharge valve RV3 to execute the sedimentation tank slag discharge control of the dissolved air flotation operation mode control task.

8. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system starts, the digital input module and the digital output module, according to the dissolved air flotation operation mode control task output by the processor module, when the water supply pump is running and the sand filter high liquid level LS2 is activated, open the pressure boosting pump outlet regulating valve RV5 to the set opening o, and start the discharge pump DP; the initial target value of FT2 is FT1; when the sand filter high liquid level LS2 is activated at a high level, the target value of FT2 increases by X% per minute; when the sand filter low liquid level LS3 is activated at a low level, the target value of FT2 decreases by x% per minute; when neither the sand filter high liquid level LS2 nor the sand filter low liquid level LS3 is activated, the target value of FT2 changes by y% per minute until it equals FT1; the pressure boosting pump outlet regulating valve RV5 uses the difference between FT2 - FT1 multiplied by the value of coefficient P as the opening target change value of the pressure boosting pump outlet regulating valve RV5. If FT2 - FT1 < FT2 and the maximum deviation difference between FT2 and FT1 is 0, the pressure boosting pump outlet regulating valve RV5 is not adjusted, and the discharge pump flow control of the dissolved air flotation operation mode control task is executed.

9. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the control system is started, the digital input module and the digital output module control the flotation operation mode according to the flotation operation mode output by the processor module. When the discharge pump DP is running, the countdown of the backwashing program starts. After the countdown ends, check whether the countdown of the concentrated slag discharge valve RV10 has ended. If not, wait for the end. If it has ended, open the concentrated slag discharge valve RV10 and keep it for the set time t6, then close the concentrated slag discharge valve RV10, open the clear water discharge valve RV11 and keep it for the set time t7, and then close the clear water discharge valve RV11. 1; After the clean water valve RV11 is closed, open the backwash pump outlet valve RV7, and then open the sand filter backwash solenoid valve RV9, and open the backwash water buffer valve RV6 for the set time t8, then start the backwash pump, and continue to open the backwash water buffer valve RV6 for the set time t9, stop the backwash pump, and close the backwash pump outlet valve RV7 and the backwash water buffer valve RV6, and execute the sand filter backwash control of the flotation operation mode control task; During the sand filter backwash control, if the clean water buffer low liquid level LS4 or the sewage buffer high liquid level LS5 is activated, the sand filter backwash control process will be terminated in advance.

10. The control system of the air-floating water treatment system for a marine dual-fuel engine according to claim 1, characterized in that: When the low liquid level of the wastewater storage tank is triggered, the digital input module and the digital output module start the shutdown program according to the shutdown mode control task output by the processor module, stop the supply pump SP, close the ultra-pH reflux valve RV2, and the PAC agent pump will automatically stop according to the position of the ultra-pH reflux valve RV2 and the flow rate of FT1, and close the bypass switching valve RV1; When the water supply pump SP stops, the digital input module and the digital output module execute the post-shutdown flotation control task output by the processor module to close the forced slag discharge valve RV3 once, then open the forced slag discharge valve RV3, stop the reflux pump, and close the dissolved air valve RV4; if the sand filter low liquid level LS3 is triggered, stop the discharge pump DP and close the booster pump outlet regulating valve RV5; When the discharge pump DP and the dissolved air pump RV4 stop, the digital input module and the digital output module check whether the countdown of the concentrated slag discharge valve RV10 is over according to the shutdown backwash control task output by the processor module. If so, perform a sand filter backwash and then end the shutdown mode; otherwise, directly stop the shutdown mode. In some preferred embodiments, the processor module, digital input module, digital output module, analog input module and analog output module are integrated on a PLC controller.

11. A control method for an air-floating water treatment system for a marine dual-fuel engine, characterized in that: The control system of the air-floating water treatment system for a marine dual-fuel engine according to any one of claims 1 to 10 is used to control the bypass operation mode, air-floating operation mode and shutdown mode of the air-floating water treatment system for a marine dual-fuel engine.

12. A computer controlled device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it can be used to run the system described in any one of claims 1 to 10.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it can be used to run the system according to any one of claims 1 to 10.

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