PLC-based conventional island dosing system and control method

Abstract

The invention discloses a PLC-based conventional island dosing system and a control method. The PLC-based conventional island dosing system comprises an upper computer, sampling equipment and dosing equipment, wherein the sampling equipment and the dosing equipment are connected with a PLC; a rotating device in the dosing device is connected with the PLC through a DI card key; the ammonia water assembly is connected with a dosing pump module in the rotating equipment; the hydrazine assembly is connected with the dosing pump module, and the dosing pump module is further connected with the secondary loop system; a chemical instrument, an ammonia water assembly and a hydrazine assembly in the sampling equipment and each frequency converter in the dosing pump module are connected with the PLC through AI card keys; the PLC is also connected with the rotating equipment through a DO card key; the PLC is further connected with each frequency converter in the dosing pump module through an AO card key, the PLC monitors the water quality of a secondary loop system based on a chemical instrument in the sampling equipment so as to control the dosing frequency of any dosing pump in the dosing pump module, and then the full-automatic dosing function is achieved.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and in particular to a conventional island dosing system based on PLC and a control method thereof. Background Art

[0002] Conventional island chemical dosing system is widely used in nuclear power plants and conventional thermal power plants. It is mainly composed of ammonia and hydrazine dosing unit and phosphate dosing unit. The function of ammonia and hydrazine dosing unit is to adjust the quality of secondary circuit water to prevent corrosion of thermal system and formation of deposits in steam generator; the function of phosphate dosing unit is to adjust the pH value of closed-loop cooling water system to prevent corrosion of equipment pipelines. Specifically, in the ammonia water unit, concentrated ammonia water flows into the ammonia solution tank through the high-level ammonia storage tank by gravity, and is configured into low-concentration ammonia water by adding SED (i.e., neutral desalted water distribution system) desalted water. The solution tank is stirred evenly by a stirrer, and ammonia water is provided to the downstream system through a dosing metering pump to adjust the pH value of the water quality; in the hydrazine unit, the purchased barreled hydrazine is added to the hydrazine solution tank through a hydrazine pump, and is configured into low-concentration hydrazine by adding SED desalted water. The solution tank is stirred evenly by a stirrer, and hydrazine is provided to the downstream system through a dosing metering pump to remove dissolved oxygen in the water; in the phosphate unit, the purchased barreled solid phosphate is added to the dissolution basket of the solution tank, and is dissolved by adding SED desalted water. The solution tank is stirred evenly by a stirrer, and phosphate is provided to the downstream system through a dosing metering pump to adjust the pH value of the closed-loop cooling water system.

[0003] However, the existing dosing system has many shortcomings, such as the need to manually operate the dosing pump, resulting in untimely or excessive dosing; the dosing process can only receive a single signal and cannot be flexibly adjusted according to the unit's operating conditions; when configuring low-concentration ammonia and other corrosive chemicals, personnel are required to manually operate on site, which poses a safety hazard. Therefore, the existing dosing system has the problem of being unable to achieve fully automatic dosing function. Summary of the invention

[0004] The purpose of the present invention is to provide a conventional island dosing system and control method based on PLC, aiming to solve the problem that the existing conventional island dosing system cannot realize the full-automatic dosing function.

[0005] In the first aspect, an embodiment of the present invention provides a conventional island dosing system based on PLC, comprising: a PLC controller, a host computer, a sampling device and a dosing device, wherein the host computer, the sampling device and the dosing device are all connected to the PLC controller; the dosing device comprises a rotating device, an ammonia water component, a hydrazine component and a secondary circuit system, and the rotating device is connected to the PLC controller via a DI card key; the ammonia water component is connected to the dosing pump module in the rotating device; the hydrazine component is connected to the dosing pump module, and the dosing pump module is also connected to the secondary circuit system; the chemical instrument in the sampling device, the ammonia water component, the hydrazine component and each inverter in the dosing pump module are connected to the PLC controller via an AI card key; the PLC controller is also connected to the dosing pump module, the mixer component and the valve component in the rotating device via a DO card key; the PLC controller is also connected to each inverter in the dosing pump module via an AO card key.

[0006] Furthermore, the dosing pump module includes a first dosing pump and a second dosing pump, the first dosing pump and the second dosing pump are connected in parallel; one end of the first dosing pump is connected to the ammonia water component, and the other end of the first dosing pump is connected to the secondary loop system; one end of the second dosing pump is connected to the ammonia water component, and the other end of the second dosing pump is connected to the secondary loop system.

[0007] Furthermore, the dosing pump module also includes a third dosing pump and a fourth dosing pump, the third dosing pump is connected in parallel with the fourth dosing pump; one end of the third dosing pump is connected to the hydrazine component, and the other end of the third dosing pump is connected to the secondary loop system; one end of the fourth dosing pump is connected to the hydrazine component, and the other end of the fourth dosing pump is connected to the secondary loop system.

[0008] Furthermore, the ammonia solution assembly includes a main ammonia solution tank and a backup ammonia solution tank, the main ammonia solution tank is connected in parallel with the backup ammonia solution tank; the liquid inlet of the main ammonia solution tank is connected to the first ammonia solution injection valve and the first desalted water injection valve in the valve assembly, and the liquid outlet of the main ammonia solution tank is connected to the first dosing pump and the second dosing pump; the liquid inlet of the backup ammonia solution tank is connected to the second ammonia solution injection valve and the second desalted water injection valve in the valve assembly, and the liquid outlet of the backup ammonia solution tank is connected to the first dosing pump and the second dosing pump.

[0009] Furthermore, the hydrazine component includes a main hydrazine solution tank and a backup hydrazine solution tank, the main hydrazine solution tank is connected in parallel with the backup hydrazine solution tank; the liquid inlet of the main hydrazine solution tank is connected to the first hydrazine injection valve and the third desalted water injection valve in the valve assembly, and the liquid outlet of the main hydrazine solution tank is connected to the third dosing pump and the fourth dosing pump; the liquid inlet of the backup hydrazine solution tank is connected to the second hydrazine injection valve and the fourth desalted water injection valve in the valve assembly, and the liquid outlet of the backup hydrazine solution tank is connected to the third dosing pump and the fourth dosing pump.

[0010] Furthermore, the system also includes a plurality of relays, which are connected to the PLC controller via the DO card key, and the plurality of relays are also connected to the valve assembly, the mixer assembly and the dosing pump module.

[0011] Furthermore, the mixer assembly includes a first mixer, a second mixer, a third mixer and a fourth mixer, and the first mixer, the second mixer, the third mixer and the fourth mixer are all connected to the PLC controller; the first mixer is arranged in the main ammonia solution tank, the second mixer is arranged in the main hydrazine solution tank, the third mixer is arranged in the standby ammonia solution tank, and the fourth mixer is arranged in the standby hydrazine solution tank.

[0012] Furthermore, a first liquid level gauge is provided in the main ammonia solution tank, and the first liquid level gauge is connected to the PLC controller.

[0013] In a second aspect, an embodiment of the present invention provides a control method for a conventional island dosing system based on PLC, which is applied to the conventional island dosing system based on PLC described in the first aspect, and the method comprises:

[0014] The PLC controller receives the medication dispensing information sent by the host computer, and detects the medication dispensing information to obtain the detection result;

[0015] If the detection result is that the dispensing information is ammonia dispensing information, the PLC controller generates a first control instruction according to the ammonia dispensing information;

[0016] The PLC controller controls the first ammonia water injection valve and the first demineralized water injection valve in the valve assembly to open, and the first mixer in the mixer assembly to start according to the first control instruction;

[0017] When the PLC controller detects that the current liquid level in the main ammonia solution tank reaches a first preset liquid level and the first mixer stops running, a first pump selection instruction is generated;

[0018] The PLC controller selects a first target dosing pump from a dosing pump module of a rotating device according to the first pump selection instruction, and determines a first chemical instrument according to the first target dosing pump;

[0019] The PLC controller determines a first start-up frequency of the first target dosing pump according to a first preset frequency algorithm and a reading in the first chemical meter, and sends the first start-up frequency to the first target dosing pump;

[0020] The first target dosing pump receives the first start-up frequency and automatically operates based on the first start-up frequency.

[0021] Furthermore, after the automatic operation based on the first startup frequency, the method further includes:

[0022] The PLC controller monitors the reading of the first chemical instrument in real time;

[0023] If the PLC controller monitors that the reading of the first chemical meter is in a first preset interval, it determines a first operating frequency corresponding to the first preset interval based on a first mapping rule, and adjusts the operating frequency of the first target dosing pump from the first starting frequency to the first operating frequency.

[0024] Further, generating a first control instruction according to the ammonia dispensing information includes:

[0025] The PLC controller calculates the first target liquid level and the target ammonia concentration value in the ammonia dispensing information to obtain the ammonia injection amount and the demineralized water injection amount;

[0026] The PLC controller generates the first control instruction according to the ammonia water injection amount and the demineralized water injection amount.

[0027] Furthermore, after obtaining the test results, the method further includes:

[0028] If the detection result is that the dispensing information is hydrazine dispensing information, the PLC controller generates a second control instruction according to the hydrazine dispensing information;

[0029] The PLC controller controls the first ammonia injection valve and the third demineralized water injection valve in the valve assembly to open, and the second mixer in the mixer assembly to start according to the second control instruction;

[0030] When the PLC controller detects that the current liquid level in the main ammonia solution tank reaches a second preset liquid level and the second mixer stops running, a second pump selection instruction is generated;

[0031] The PLC controller selects a second target dosing pump from the dosing pump module according to the second pump selection instruction, and determines a second chemical instrument according to the second target dosing pump;

[0032] The PLC controller determines a second start-up frequency of the second target dosing pump according to a second mapping rule and a second target reading in the second chemical meter, and sends the second start-up frequency to the second target dosing pump;

[0033] The second target dosing pump receives the second start-up frequency and automatically operates based on the second start-up frequency.

[0034] Furthermore, the method further comprises:

[0035] The PLC controller obtains the historical solution data of the main ammonia solution tank and sends the historical solution data to the host computer; wherein the historical solution data includes the historical liquid level height and the historical ammonia concentration;

[0036] The host computer receives the historical solution data and generates a historical curve report according to the historical solution data.

[0037] The invention discloses a conventional island dosing system and control method based on PLC, comprising: a host computer, a sampling device and a dosing device are all connected to a PLC controller; a rotating device in the dosing device is connected to the PLC controller through a DI card key; an ammonia water component is connected to a dosing pump module in the rotating device; a hydrazine component is connected to the dosing pump module, and the dosing pump module is also connected to a secondary circuit system; a chemical instrument in the sampling device, an ammonia water component, a hydrazine component and each frequency converter in the dosing pump module are all connected to the PLC controller through an AI card key; the PLC controller is also connected to the rotating device through a DO card key; the PLC controller is also connected to each frequency converter in the dosing pump module through an AO card key. The PLC controller in the invention monitors the water quality of the secondary circuit system based on the chemical instrument in the sampling device to control the dosing frequency of any dosing pump in the dosing pump module, thereby realizing a fully automatic dosing function. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0039] Figure 1 A schematic block diagram of a conventional island dosing system based on PLC provided in an embodiment of the present invention;

[0040] Figure 2 A schematic block diagram of a dosing device in a conventional island dosing system based on PLC provided in an embodiment of the present invention;

[0041] Figure 3 A first flow chart of a control method for a conventional island dosing system based on PLC provided in an embodiment of the present invention;

[0042] Figure 4 A second flow chart of a control method for a conventional island dosing system based on PLC provided in an embodiment of the present invention.

[0043] Among them, the reference numerals in the figures are as follows:

[0044] 10. PLC controller; 20. Host computer; 30. Sampling equipment; 31. Chemical instrument; 40. Dosing equipment; 41. Rotating equipment; 411. Dosing pump module; 4111. First dosing pump; 4112. Second dosing pump; 4113. Third dosing pump; 4114. Fourth dosing pump; 4115. Frequency converter; 412. Valve assembly; 4121. First ammonia injection valve; 4122. Second ammonia injection valve ; 4123, first hydrazine injection valve; 4124, second hydrazine injection valve; 413, mixer assembly; 42, ammonia solution assembly; 421, main ammonia solution tank; 422, spare ammonia solution tank; 43, hydrazine assembly; 431, main hydrazine solution tank; 432, spare hydrazine solution tank; 44, secondary circuit system; 50, relay; 60, AI card key; 70, DI card key; 80, AO card key; 90, DO card key. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0047] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0048] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0049] See also Figure 1 , Figure 1 A schematic block diagram of a conventional island dosing system based on PLC provided in an embodiment of the present invention; Figure 2 FIG. 4 is a schematic block diagram of a dosing device 40 in a conventional island dosing system based on PLC according to an embodiment of the present invention. Figure 1-2 As shown, the embodiment of the present invention proposes a conventional island dosing system based on PLC, including: a PLC controller 10, a host computer 20, a sampling device 30 and a dosing device 40, wherein the host computer 20, the sampling device 30 and the dosing device 40 are all connected to the PLC controller 10; the dosing device 40 includes a rotating device 41, an ammonia component 42, a hydrazine component 43 and a secondary circuit system 44, wherein the rotating device 41 is connected to the PLC controller 10 via a DI card key 70; the ammonia component 42 is connected to a dosing pump module 411 in the rotating device 41; the hydrazine component 43 is connected to the dosing pump module The dosing pump module 411 is connected to the secondary circuit system 44; the chemical instrument 31 in the sampling device 30, the ammonia component 42, the hydrazine component 43 and each frequency converter 4115 in the dosing pump module 411 are connected to the PLC controller 10 through the AI ​​card key 60; the PLC controller 10 is also connected to the dosing pump module 411, the mixer component 413 and the valve component 412 in the rotating device 41 through the DO card key 90; the PLC controller 10 is also connected to each frequency converter 4115 in the dosing pump module 411 through the AO card key 80.

[0050] In this embodiment, the conventional island dosing system based on PLC mainly includes a PLC controller 10, a host computer 20, a sampling device 30 and a dosing device 40; wherein, the host computer 20 in this embodiment is connected to the communication card key in the PLC controller 10 through a network cable to realize communication connection, so that various information of the dosing device 40 obtained from the PLC controller 10 is displayed through the host computer 20, and the reading of the chemical instrument 31 of the sampling device 30 can be switched to display; and a dosing pump automatic operation window is provided on the interface of the host computer 20, and the signal for the automatic operation of the dosing pump can be selected according to the operating conditions of the system unit. For example, during the hot test, the pH value of the main feed water can be associated to control the operating frequency of the corresponding frequency converter 4115 in the dosing pump that adds ammonia water to the ADG (feed water deaerator system) in the secondary circuit system 44, so as to realize automatic dosing of the secondary circuit system 44. The upper computer 20 interface is also provided with a dispensing window, so that the relevant user can set the dispensing information such as the liquid level height and the ammonia concentration value, so as to send the dispensing information to the PLC controller 10, and the PLC controller 10 controls the rotating device 41, the ammonia component 42 and the hydrazine component 43 in the dosing device 40 to perform the corresponding dispensing operation without the need for manual configuration on site; in addition, this embodiment does not specifically limit the display window of the upper computer 20 interface, and the user can set it according to actual needs. In addition, the PLC controller 10 monitors the device data and status information of the valve component 412, the mixer component 413 and the dosing pump module 411 of the rotating device 41 in the dosing device 40 in real time through the DI card key 70, such as the switch of the valve component 412. And the sampling device 30 is connected to the PLC controller 10 through the AI ​​card key 60, so that the PLC controller 10 can obtain the reading of the chemical instrument 31 in the sampling device 30; wherein, the chemical instrument 31 in this embodiment has instruments such as a hydrazine meter and a pH meter. In addition, each frequency converter 4115 in the ammonia water component 42, the hydrazine component 43 and the dosing pump module 411 is also connected to the PLC controller 10 through the AI ​​card key 60, so that the PLC controller 10 receives the liquid level information of the solution tank in the ammonia water component 42, the liquid level information of the solution tank in the hydrazine component 43 and the operating frequency of each frequency converter 4115. Specifically, the dosing device 40 also includes an ammonia water component 42, a hydrazine component 43 and a secondary loop system 44, the ammonia water component 42 is connected to the dosing pump module 411 in the rotating device 41, the hydrazine component 43 is connected to the dosing pump module 411, the dosing pump module 411 is also connected to the secondary loop system 44, and the secondary loop system 44 is connected to the sampling device 30, so that the water quality of the secondary loop system 44 is monitored by the sampling device 30, and the water quality of the secondary loop system 44 is fed back and displayed through the chemical meter 31.In addition, the dosing equipment 40 also includes an ammonia tank truck for providing concentrated ammonia water to the ammonia component 42, an ammonia magnetic pump for unloading ammonia water and an ammonia storage tank, and a hydrazine barrel and a hydrazine pump for providing hydrazine to the hydrazine component 43, and also includes an ammonia / hydrazine solution tank and a phosphate unit (not shown). In addition, the PLC controller 10 is also connected to each inverter 4115 in the dosing pump module 411 through the AO card key 80, so that the PLC controller 10 can control the operating frequency of the inverter 4115 in the corresponding dosing pump in the dosing pump module 411 according to the reading of the chemical meter 31, and then adjust the dosing amount to the secondary circuit system 44 in real time to realize the fully automatic dosing function. The PLC controller 10 is also connected to the valve assembly 412, the hydrazine assembly 43 and the dosing pump module 411 in the rotating device 41 through the DO card key 90 to issue control instructions to the valve assembly 412 and the hydrazine assembly 43, such as controlling the start and stop of the mixer in the mixer assembly 413, the valve switch in the valve assembly 412, etc. In addition, the secondary loop system 44 also includes CEX (condensate extraction system), ADG (feedwater deaerator system), SIH (nuclear island chemical dosing system), AAS (startup and shutdown auxiliary feedwater system) and other systems.

[0051] In one embodiment, if Figure 1-2 As shown, the dosing pump module 411 includes a first dosing pump 4111 and a second dosing pump 4112, and the first dosing pump 4111 is connected in parallel with the second dosing pump 4112; one end of the first dosing pump 4111 is connected to the ammonia water component 42, and the other end of the first dosing pump 4111 is connected to the secondary loop system 44; one end of the second dosing pump 4112 is connected to the ammonia water component 42, and the other end of the second dosing pump 4112 is connected to the secondary loop system 44.

[0052] In this embodiment, the dosing pump module 411 includes a first dosing pump 4111 and a second dosing pump 4112; wherein, the first dosing pump 4111 and the second dosing pump 4112 are connected in parallel, responsible for extracting ammonia solution from the ammonia solution component 42 and transporting it to the secondary loop system 44 to adjust the pH value of the water quality in the secondary loop system 44; thus, through the parallel configuration, it can be ensured that when one of the dosing pumps fails, the other dosing pump can continue to work to ensure the normal operation of the ammonia solution component 42. In addition, the first dosing pump 4111 and the second dosing pump 4112 are both provided with a frequency converter 4115, so that the dosing amount can be adjusted by dynamically adjusting the operating frequency of the frequency converter 4115 in the first dosing pump 4111 and the second dosing pump 4112, and the delivery amount can be accurately adjusted according to the actual needs of the secondary circuit system 44 to avoid insufficient or excessive dosing that causes the water quality of the secondary circuit system 44 to exceed the preset threshold range.

[0053] In one embodiment, if Figure 1-2 As shown, the dosing pump module 411 also includes a third dosing pump 4113 and a fourth dosing pump 4114, the third dosing pump 4113 is connected in parallel with the fourth dosing pump 4114; one end of the third dosing pump 4113 is connected to the hydrazine component 43, and the other end of the third dosing pump 4113 is connected to the secondary loop system 44; one end of the fourth dosing pump 4114 is connected to the hydrazine component 43, and the other end of the fourth dosing pump 4114 is connected to the secondary loop system 44.

[0054] In this embodiment, the dosing pump module 411 further includes a third dosing pump 4113 and a fourth dosing pump 4114; wherein the third dosing pump 4113 and the fourth dosing pump 4114 are also connected in parallel, but the two dosing pumps are responsible for extracting hydrazine solution from the hydrazine component 43 and delivering it to the secondary loop system 44, thereby providing hydrazine to the secondary loop system 44 to remove dissolved oxygen in the water. In addition, each of the third dosing pump 4113 and the fourth dosing pump 4114 is also provided with a frequency converter 4115, so that the dosing amount can also be adjusted by dynamically adjusting the operating frequency of the frequency converter 4115 in the third dosing pump 4113 and the fourth dosing pump 4114, and the delivery amount can be accurately adjusted according to the actual needs of the secondary loop system 44 to avoid insufficient or excessive dosing that causes the water quality of the secondary loop system 44 to exceed the preset threshold range. In addition, the dosing pump module 411 also includes a fifth dosing pump, one end of the fifth dosing pump is connected to the ammonia / hydrazine solution tank, and the other end is connected to the SIH (nuclear island chemical dosing system) and AAS (startup and shutdown auxiliary water supply system) in the secondary loop system 44 to provide ammonia water or hydrazine solution.

[0055] In one embodiment, if Figure 1-2 As shown, the ammonia solution component 42 includes a main ammonia solution tank 421 and a spare ammonia solution tank 422, and the main ammonia solution tank 421 is connected in parallel with the spare ammonia solution tank 422; the liquid inlet of the main ammonia solution tank 421 is connected to the first ammonia solution injection valve 4121 and the first desalted water injection valve (not shown) in the valve component 412, and the liquid outlet of the main ammonia solution tank 421 is connected to the first dosing pump 4111 and the second dosing pump 4112; the liquid inlet of the spare ammonia solution tank 422 is connected to the second ammonia solution injection valve 4122 and the second desalted water injection valve (not shown) in the valve component 412, and the liquid outlet of the spare ammonia solution tank 422 is connected to the first dosing pump 4111 and the second dosing pump 4112.

[0056] In this embodiment, in order to ensure that the system can continue to operate when the main ammonia solution tank 421 fails or is under maintenance, a spare ammonia solution tank 422 is also provided in the ammonia component 42; and the main ammonia solution tank 421 is connected in parallel with the spare ammonia solution tank 422; the liquid inlet of the main ammonia solution tank 421 is connected to both the first ammonia solution injection valve 4121 and the first desalted water injection valve in the valve assembly 412; wherein, the first ammonia solution injection valve 4121 is used to control the injection amount of ammonia solution; the first desalted water injection valve is used to control the injection amount of desalted water; and the desalted water is generally used to adjust the concentration of ammonia solution to reach the desired pH value. During the dispensing process, the first ammonia solution injection valve 4121 and the first desalted water injection valve are both connected to the liquid inlet of the main ammonia solution tank 421, so that ammonia solution enters the main ammonia solution tank 421 through the first ammonia solution injection valve 4121, and desalted water enters the main ammonia solution tank 421 through the first desalted water injection valve; at the same time, the prepared ammonia solution is delivered to any one of the first dosing pump 4111 and the second dosing pump 4112 through the liquid outlet of the main ammonia solution tank 421. In addition, the second ammonia solution injection valve 4122 has the same function as the first ammonia solution injection valve 4121, the second desalted water injection valve has the same function as the first desalted water injection valve, and the standby ammonia solution tank 422 has the same function as the main ammonia solution tank 421. And the standby ammonia solution tank 422 is a redundant system of the main ammonia solution tank 421, providing an alternative solution when the main ammonia solution tank 421 cannot be used to ensure that the system can continue to operate, thereby improving the reliability and redundancy of the entire ammonia solution assembly 42.

[0057] In one embodiment, if Figure 1-2 As shown, the hydrazine component 43 includes a main hydrazine solution tank 431 and a spare hydrazine solution tank 432, and the main hydrazine solution tank 431 is connected in parallel with the spare hydrazine solution tank 432; the liquid inlet of the main hydrazine solution tank 431 is connected to the first hydrazine injection valve 4123 and the third desalted water injection valve in the valve component 412, and the liquid outlet of the main hydrazine solution tank 431 is connected to the third dosing pump 4113 and the fourth dosing pump 4114; the liquid inlet of the spare hydrazine solution tank 432 is connected to the second hydrazine injection valve 4124 and the fourth desalted water injection valve in the valve component 412, and the liquid outlet of the spare hydrazine solution tank 432 is connected to the third dosing pump 4113 and the fourth dosing pump 4114.

[0058] In this embodiment, the hydrazine component 43 is provided with a main hydrazine solution tank 431 and a backup hydrazine solution tank 432; and the main hydrazine solution tank 431 is connected in parallel with the backup hydrazine solution tank 432; the liquid inlet of the main hydrazine solution tank 431 is connected to both the first hydrazine injection valve 4123 and the third desalted water injection valve in the valve component 412; wherein, the first hydrazine injection valve 4123 is used to control the injection amount of hydrazine; the third desalted water injection valve is used to control the injection amount of desalted water; and desalted water is generally used to adjust the concentration of the hydrazine solution. During the dispensing process, the first hydrazine injection valve 4123 and the third desalted water injection valve are both connected to the liquid inlet of the main hydrazine solution tank 431, so that hydrazine enters the main hydrazine solution tank 431 through the first hydrazine injection valve 4123, and desalted water enters the main hydrazine solution tank 431 through the third desalted water injection valve; at the same time, the prepared hydrazine solution is transported to any one of the third dosing pump 4113 and the fourth dosing pump 4114 through the liquid outlet of the main hydrazine solution tank 431. In addition, the second hydrazine injection valve 4124 has the same function as the first hydrazine injection valve 4123, the fourth desalted water injection valve has the same function as the third desalted water injection valve, and the backup hydrazine solution tank 432 has the same function as the main hydrazine solution tank 431; and the backup hydrazine solution tank 432 is a redundant system of the main hydrazine solution tank 431, providing an alternative solution when the main hydrazine solution tank 431 cannot be used, to ensure that the system can continue to operate, thereby improving the reliability and redundancy of the entire hydrazine assembly 43.

[0059] In one embodiment, if Figure 1-2 As shown, the system further includes a plurality of relays 50 , which are connected to the PLC controller 10 via the DO card key 90 , and are also connected to the valve assembly 412 , the mixer assembly 413 and the dosing pump module 411 .

[0060] In this embodiment, the conventional island dosing system based on PLC further includes a plurality of relays 50, wherein the plurality of relays 50 are connected to the PLC controller 10 through the DO card key 90, so as to control the power on or off of the corresponding relays 50 in the plurality of relays 50 by receiving the on / off signal sent by the PLC controller 10, thereby controlling the start / stop or switch of the valve assembly 412, the mixer assembly 413 and the dosing pump module 411 connected to the corresponding relays 50 in the plurality of relays 50. The plurality of relays 50 correspond to each injection valve in the valve assembly 412, each mixer in the mixer assembly 413, and each dosing pump in the dosing pump module 411 one by one, so as to control the on / off of each relay 50 in the plurality of relays 50 through the PLC controller 10 to trigger the switch or start / stop of the corresponding injection valve, dosing pump or mixer, thereby realizing the automatic dispensing function.

[0061] In one embodiment, if Figure 1-2 As shown, the mixer assembly 413 includes a first mixer (not shown), a second mixer (not shown), a third mixer (not shown) and a fourth mixer (not shown), and the first mixer, the second mixer, the third mixer and the fourth mixer are all connected to the PLC controller 10; the first mixer is arranged in the main ammonia solution tank 421, the second mixer is arranged in the main hydrazine solution tank 431, the third mixer is arranged in the standby ammonia solution tank 422, and the fourth mixer is arranged in the standby hydrazine solution tank 432.

[0062] In this embodiment, the mixer assembly 413 includes a first mixer, a second mixer, a third mixer and a fourth mixer; wherein the first mixer, the second mixer, the third mixer and the fourth mixer are all connected to the PLC controller 10, so that the PLC controller 10 can know the state of the first mixer in real time. Moreover, the first mixer, the second mixer, the third mixer and the fourth mixer are respectively arranged in the main ammonia solution tank 421, the main hydrazine solution tank 431, the standby ammonia solution tank 422 and the standby hydrazine solution tank 432; specifically, when ammonia water enters the main ammonia solution tank 421 through the first ammonia water injection valve 4121, and desalted water enters the main ammonia solution tank 421 through the first desalted water injection valve, the ammonia water and the desalted water can be fully mixed and uniformly under the action of the first mixer. wherein, the functions of the second mixer, the third mixer and the fourth mixer are respectively the same as those of the first mixer, and are not described one by one here.

[0063] In one embodiment, if Figure 1-2As shown, a first liquid level gauge (not shown) is also provided in the main ammonia solution tank 421 , and the first liquid level gauge is connected to the PLC controller 10 .

[0064] In this embodiment, a first liquid level gauge is provided in the main ammonia solution tank 421; wherein, the first liquid level gauge is connected to the PLC controller 10 via the AI ​​card key 60, so that the PLC controller 10 can know the status of the second liquid level gauge in real time. In addition, in this embodiment, a second liquid level gauge is provided in the main ammonia solution tank 431, a third liquid level gauge is provided in the standby ammonia solution tank 422, and a fourth liquid level gauge is provided in the standby ammonia solution tank 432; wherein, the second liquid level gauge, the third liquid level gauge and the fourth liquid level gauge are all connected to the PLC controller 10 via the AI ​​card key 60, and the second liquid level gauge, the third liquid level gauge and the fourth liquid level gauge all have the same function as the first liquid level gauge, which will not be described one by one here.

[0065] See also Figure 3-4 , Figure 3 A first flow chart of a control method for a conventional island dosing system based on PLC provided in an embodiment of the present invention; Figure 4 The second flow chart of the control method of the conventional island dosing system based on PLC provided by the embodiment of the present invention. The embodiment of the present invention also provides a control method of the conventional island dosing system based on PLC, which is applied to the conventional island dosing system based on PLC, and the method includes steps S110-S170.

[0066] S110, the PLC controller receives the medication information sent by the host computer, and detects the medication information to obtain a detection result;

[0067] S120: If the detection result shows that the dispensing information is ammonia dispensing information, the PLC controller generates a first control instruction according to the ammonia dispensing information;

[0068] S130, the PLC controller controls the first ammonia water injection valve and the first demineralized water injection valve in the valve assembly to open, and the first mixer in the mixer assembly to start according to the first control instruction;

[0069] S140, when the PLC controller detects that the current liquid level in the main ammonia solution tank reaches a first preset liquid level and the first mixer stops running, a first pump selection instruction is generated;

[0070] S150, the PLC controller selects a first target dosing pump from a dosing pump module of a rotating device according to the first pump selection instruction, and determines a first chemical instrument according to the first target dosing pump;

[0071] S160, the PLC controller determines a first starting frequency of the first target dosing pump according to a first preset frequency algorithm and a reading in the first chemical meter, and sends the first starting frequency to the first target dosing pump;

[0072] S170: The first target dosing pump receives the first starting frequency, and automatically operates based on the first starting frequency.

[0073] In this embodiment, in order to realize the automation of the entire process of dispensing and adding medicines, the PLC controller in this embodiment first receives the dispensing information sent by the upper computer and detects the dispensing information to ensure the accuracy and completeness of the dispensing information; if it is detected that the dispensing information is ammonia water dispensing information, the PLC controller generates a first control instruction according to the ammonia water dispensing information; wherein the ammonia water dispensing information includes a target liquid level and an ammonia water concentration value, thereby generating a first control instruction based on the first target liquid level and the ammonia water concentration value to control the first ammonia water injection valve and the first desalted water injection valve in the valve assembly to open, thereby injecting a certain amount of ammonia water solution and a certain amount of desalted water into the main ammonia water solution tank in the ammonia water assembly; at the same time, the first mixer in the mixer assembly is started to mix the ammonia water solution and the desalted water. The PLC controller continuously monitors the liquid level in the main ammonia solution tank. When it is detected that the current liquid level in the main ammonia solution tank reaches the first preset liquid level and the first mixer stops running, it means that the ammonia solution and the demineralized water have been mixed evenly and the dispensing operation has been completed. At this time, the first pump selection instruction is generated to select the corresponding dosing pump and chemical instrument. Afterwards, the PLC controller selects any dosing pump from the first dosing pump and the second dosing pump in the dosing pump module of the rotating equipment as the first target dosing pump according to the first pump selection instruction, and determines the first chemical instrument associated with it according to the first target dosing pump; since ammonia affects the pH value of the water quality in the secondary loop system, it can be determined that the first chemical instrument associated with the first target dosing pump is a pH meter; the PLC controller can also perform calculations and analysis based on the first preset frequency algorithm and the readings in the first chemical instrument to determine the first starting frequency of the first target dosing pump; and send the first starting frequency to the first target dosing pump, so that the frequency converter in the first target dosing pump can automatically operate based on the received first starting frequency, thereby realizing the automatic dosing function.

[0074] In one embodiment, after step S170, the method further includes:

[0075] The PLC controller monitors the reading of the first chemical instrument in real time;

[0076] If the PLC controller monitors that the reading of the first chemical meter is in a first preset interval, it determines a first operating frequency corresponding to the first preset interval based on a first mapping rule, and adjusts the operating frequency of the first target dosing pump from the first starting frequency to the first operating frequency.

[0077] In this embodiment, after the frequency converter in the first target dosing pump automatically operates based on the first starting frequency, during the automatic dosing process, the PLC controller monitors the reading of the first chemical meter (i.e., pH value) in real time; wherein, when the PLC controller detects that the reading of the first chemical meter is in the first preset interval, the first operating frequency corresponding to the first preset interval is obtained from the first mapping rule, and the operating frequency of the first target dosing pump is adjusted according to the first operating frequency, from the original first starting frequency to the first operating frequency. The first mapping rule includes multiple pH intervals and multiple operating frequencies, and each of the multiple pH intervals has a one-to-one mapping relationship with the corresponding operating frequency. In this embodiment, during the dosing process, the operating frequency of the first target dosing pump is dynamically adjusted according to the real-time water quality of the secondary loop system fed back according to the reading of the first chemical meter, so as to achieve precise control of the dosing amount, thereby avoiding the situation where the water quality of the secondary loop system exceeds the preset specified range due to insufficient or excessive dosing.

[0078] In one embodiment, generating a first control instruction according to the ammonia solution dispensing information includes:

[0079] The PLC controller calculates the first target liquid level and the target ammonia concentration value in the ammonia dispensing information to obtain the ammonia injection amount and the demineralized water injection amount;

[0080] The PLC controller generates the first control instruction according to the ammonia water injection amount and the demineralized water injection amount.

[0081] In this embodiment, in terms of ammonia water configuration, the PLC controller first calculates and analyzes the target liquid level and the target ammonia water concentration value in the ammonia water dispensing information to obtain the ammonia water injection amount and the desalted water injection amount; for example: dilute 27.6% concentrated ammonia water in the ammonia storage tank into 6% dilute ammonia water, then the concentrated ammonia water injection amount: the desalted water injection amount = 1:3.6; in addition, the PLC controller also generates a first control instruction based on the ammonia water injection amount and the desalted water injection amount to control the switching of the first ammonia water injection valve and the first desalted water injection valve to realize remote dispensing, thereby minimizing personnel contact with corrosive ammonia water with a pungent odor and eliminating the safety hazards of on-site dispensing.

[0082] In one embodiment, after step S110, the method further includes:

[0083] S210, if the detection result is that the dispensing information is hydrazine dispensing information, the PLC controller generates a second control instruction according to the hydrazine dispensing information;

[0084] S220, the PLC controller controls the first ammonia injection valve and the third demineralized water injection valve in the valve assembly to open, and the second mixer in the mixer assembly to start according to the second control instruction;

[0085] S230, when the PLC controller detects that the current liquid level in the main ammonia solution tank reaches a second preset liquid level and the second mixer stops running, a second pump selection instruction is generated;

[0086] S240, the PLC controller selects a second target dosing pump from the dosing pump module according to the second pump selection instruction, and determines a second chemical instrument according to the second target dosing pump;

[0087] S250, the PLC controller determines a second starting frequency of the second target dosing pump according to a second mapping rule and a second target reading in the second chemical meter, and sends the second starting frequency to the second target dosing pump;

[0088] S260: The second target dosing pump receives the second starting frequency, and automatically operates based on the second starting frequency.

[0089] In this embodiment, after the dispensing information is detected, if it is detected that the dispensing information is hydrazine dispensing information, the PLC controller generates a second control instruction according to the hydrazine dispensing information; wherein the hydrazine dispensing information includes a second target liquid level and a hydrazine concentration value, so that the second control instruction is generated based on the second target liquid level and the hydrazine concentration value to control the second ammonia injection valve and the third desalted water injection valve in the valve assembly to open, so as to inject a certain amount of hydrazine solution and a certain amount of desalted water into the main hydrazine solution tank in the hydrazine assembly; and at the same time, the second mixer in the mixer assembly is started to mix the hydrazine solution and the desalted water. The PLC controller continuously monitors the liquid level in the main hydrazine solution tank. When it is detected that the current liquid level in the main hydrazine solution tank reaches the second preset liquid level and the second mixer stops running, it means that the hydrazine solution and the desalted water have been mixed evenly and the dispensing operation has been completed. At this time, a second pump selection instruction is generated to select the corresponding dosing pump and chemical instrument. Afterwards, the PLC controller selects any one of the third and fourth dosing pumps in the dosing pump module as the second target dosing pump according to the second pump selection instruction, and determines the second chemical meter associated with the second target dosing pump according to the second target dosing pump; since hydrazine affects the water quality in the secondary circuit system, it can be determined that the second chemical meter associated with the second target dosing pump is the hydrazine meter; the PLC controller can also perform calculations and analyses based on the second preset frequency algorithm and the readings in the second chemical meter to determine the second starting frequency of the second target dosing pump; and send the second starting frequency to the second target dosing pump, so that the frequency converter in the second target dosing pump can automatically operate based on the received second starting frequency, thereby realizing the automatic dosing function.

[0090] In one embodiment, the method further comprises:

[0091] The PLC controller obtains the historical solution data of the main ammonia solution tank and sends the historical solution data to the host computer; wherein the historical solution data includes the historical liquid level height and the historical ammonia concentration;

[0092] The host computer receives the historical solution data and generates a historical curve report according to the historical solution data.

[0093] In this embodiment, the PLC controller can not only monitor the dosing equipment and sampling equipment in real time, but also obtain and process the historical data of each device in the dosing equipment and sampling equipment. The PLC controller in this embodiment obtains the historical solution data of the main ammonia solution tank; wherein, the historical solution data includes the historical liquid level height and the historical ammonia concentration; in addition, the PLC controller also sends the historical solution data to the host computer. Once the host computer receives the historical solution data, it generates a historical curve report based on the historical solution data for display, so that the relevant staff can intuitively understand the historical operating status of the main ammonia solution tank, such as the liquid level height and ammonia concentration change trend of the main ammonia solution tank. In addition, the PLC controller can also monitor the operating status of each device in the dosing equipment in real time; when the PLC controller detects that the dosing equipment is in an abnormal state, it generates an abnormal alarm prompt and sends the abnormal alarm prompt to the host computer, so that the relevant operators can timely check the abnormality, thereby ensuring the normal operation of the system.

[0094] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A conventional island dosing system based on PLC, characterized in that: include: PLC controller, host computer, sampling equipment and dosing equipment, the host computer, the sampling equipment and the dosing equipment are all connected to the PLC controller; the dosing equipment includes a rotating device, an ammonia component, a hydrazine component and a secondary circuit system, the rotating device is connected to the PLC controller through a DI card key; the ammonia component is connected to the dosing pump module in the rotating device; the hydrazine component is connected to the dosing pump module, and the dosing pump module is also connected to the secondary circuit system; the chemical instrument in the sampling device, the ammonia component, the hydrazine component and each frequency converter in the dosing pump module are connected to the PLC controller through an AI card key; the PLC controller is also connected to the dosing pump module, the mixer component and the valve component in the rotating device through a DO card key; the PLC controller is also connected to each frequency converter in the dosing pump module through an AO card key.

2. The conventional island dosing system based on PLC according to claim 1 is characterized in that: The dosing pump module includes a first dosing pump and a second dosing pump, the first dosing pump and the second dosing pump are connected in parallel; one end of the first dosing pump is connected to the ammonia water component, and the other end of the first dosing pump is connected to the secondary circuit system; one end of the second dosing pump is connected to the ammonia water component, and the other end of the second dosing pump is connected to the secondary circuit system.

3. The conventional island dosing system based on PLC according to claim 2 is characterized in that: The dosing pump module also includes a third dosing pump and a fourth dosing pump, the third dosing pump is connected in parallel with the fourth dosing pump; one end of the third dosing pump is connected to the hydrazine component, and the other end of the third dosing pump is connected to the secondary circuit system; one end of the fourth dosing pump is connected to the hydrazine component, and the other end of the fourth dosing pump is connected to the secondary circuit system.

4. The conventional island dosing system based on PLC according to claim 3 is characterized in that: The ammonia solution assembly includes a main ammonia solution tank and a backup ammonia solution tank, the main ammonia solution tank is connected in parallel with the backup ammonia solution tank; the liquid inlet of the main ammonia solution tank is connected to both the first ammonia solution injection valve and the first desalted water injection valve in the valve assembly, and the liquid outlet of the main ammonia solution tank is connected to both the first dosing pump and the second dosing pump; the liquid inlet of the backup ammonia solution tank is connected to the second ammonia solution injection valve and the second desalted water injection valve in the valve assembly, and the liquid outlet of the backup ammonia solution tank is connected to both the first dosing pump and the second dosing pump.

5. The conventional island dosing system based on PLC according to claim 4 is characterized in that: The hydrazine assembly includes a main hydrazine solution tank and a spare hydrazine solution tank, the main hydrazine solution tank is connected in parallel with the spare hydrazine solution tank; the liquid inlet of the main hydrazine solution tank is connected to the first hydrazine injection valve and the third desalted water injection valve in the valve assembly, and the liquid outlet of the main hydrazine solution tank is connected to the third dosing pump and the fourth dosing pump; the liquid inlet of the spare hydrazine solution tank is connected to the second hydrazine injection valve and the fourth desalted water injection valve in the valve assembly, and the liquid outlet of the spare hydrazine solution tank is connected to the third dosing pump and the fourth dosing pump.

6. The conventional island dosing system based on PLC according to claim 1 is characterized in that: The system also includes a plurality of relays, which are connected to the PLC controller via the DO card key, and are also connected to the valve assembly, the mixer assembly and the dosing pump module.

7. The conventional island dosing system based on PLC according to claim 5 is characterized in that: The mixer assembly includes a first mixer, a second mixer, a third mixer and a fourth mixer, and the first mixer, the second mixer, the third mixer and the fourth mixer are all connected to the PLC controller; the first mixer is arranged in the main ammonia solution tank, the second mixer is arranged in the main hydrazine solution tank, the third mixer is arranged in the standby ammonia solution tank, and the fourth mixer is arranged in the standby hydrazine solution tank.

8. The conventional island dosing system based on PLC according to claim 4 is characterized in that: A first liquid level gauge is also provided in the main ammonia solution tank, and the first liquid level gauge is connected to the PLC controller via an AI card key.

9. A control method for a conventional island dosing system based on PLC, applied to the conventional island dosing system based on PLC as claimed in any one of claims 1 to 8, characterized in that: The method comprises: The PLC controller receives the medication dispensing information sent by the host computer, and detects the medication dispensing information to obtain the detection result; If the detection result is that the dispensing information is ammonia dispensing information, the PLC controller generates a first control instruction according to the ammonia dispensing information; The PLC controller controls the first ammonia water injection valve and the first demineralized water injection valve in the valve assembly to open, and the first mixer in the mixer assembly to start according to the first control instruction; When the PLC controller detects that the current liquid level in the main ammonia solution tank reaches a first preset liquid level and the first mixer stops running, a first pump selection instruction is generated; The PLC controller selects a first target dosing pump from a dosing pump module of a rotating device according to the first pump selection instruction, and determines a first chemical instrument according to the first target dosing pump; The PLC controller determines a first start-up frequency of the first target dosing pump according to a first preset frequency algorithm and a reading in the first chemical meter, and sends the first start-up frequency to the first target dosing pump; The first target dosing pump receives the first start-up frequency and automatically operates based on the first start-up frequency.

10. The control method of the conventional island dosing system based on PLC according to claim 9 is characterized in that: After the automatic operation based on the first startup frequency, the method further includes: The PLC controller monitors the reading of the first chemical instrument in real time; If the PLC controller monitors that the reading of the first chemical meter is in a first preset interval, it determines a first operating frequency corresponding to the first preset interval based on a first mapping rule, and adjusts the operating frequency of the first target dosing pump from the first starting frequency to the first operating frequency.

11. The control method of the conventional island dosing system based on PLC according to claim 9 is characterized in that: The generating of the first control instruction according to the ammonia dispensing information comprises: The PLC controller calculates the first target liquid level and the target ammonia concentration value in the ammonia dispensing information to obtain the ammonia injection amount and the demineralized water injection amount; The PLC controller generates the first control instruction according to the ammonia water injection amount and the demineralized water injection amount.

12. The control method of the conventional island dosing system based on PLC according to claim 9 is characterized in that: After obtaining the test result, the method further includes: If the detection result is that the dispensing information is hydrazine dispensing information, the PLC controller generates a second control instruction according to the hydrazine dispensing information; The PLC controller controls the first ammonia injection valve and the third demineralized water injection valve in the valve assembly to open, and the second mixer in the mixer assembly to start according to the second control instruction; When the PLC controller detects that the current liquid level in the main ammonia solution tank reaches a second preset liquid level and the second mixer stops running, a second pump selection instruction is generated; The PLC controller selects a second target dosing pump from the dosing pump module according to the second pump selection instruction, and determines a second chemical instrument according to the second target dosing pump; The PLC controller determines a second start-up frequency of the second target dosing pump according to a second mapping rule and a second target reading in the second chemical meter, and sends the second start-up frequency to the second target dosing pump; The second target dosing pump receives the second start-up frequency and automatically operates based on the second start-up frequency.

13. The control method of the conventional island dosing system based on PLC according to claim 9 is characterized in that: The method further comprises: The PLC controller obtains the historical solution data of the main ammonia solution tank and sends the historical solution data to the host computer; wherein the historical solution data includes the historical liquid level height and the historical ammonia concentration; The host computer receives the historical solution data and generates a historical curve report according to the historical solution data.

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