CN111620438B

CN111620438B - Optimal control method for reducing energy consumption of ICEAS sewage treatment process

Info

Publication number: CN111620438B
Application number: CN202010483154.6A
Authority: CN
Inventors: 刘志远
Original assignee: Huanggang Yigao Water Service Co ltd; BEIJING CAPITAL CO LTD
Current assignee: Huanggang Yigao Water Service Co ltd; BEIJING CAPITAL CO LTD
Priority date: 2020-06-01
Filing date: 2020-06-01
Publication date: 2022-08-02
Anticipated expiration: 2040-06-01
Also published as: CN111620438A

Abstract

The invention provides an optimal control method for reducing energy consumption of an ICEAS sewage treatment process, which comprises the following steps: and (3) precipitation control: closing the water inlet opening and closing machine for starting precipitation, opening the water inlet opening and closing machine in a delayed mode, and performing first water injection sinking on the water decanter according to the first water injection time; decanting control: when the water supply system is started, the drain valve is opened, and after the delay time, the water inlet opening and closing machine is closed; when the water is finished, the water inlet hoist starts to be opened under the action of a 'closing' signal of the drain valve; and (3) stirring: setting a stirring delay, and performing second water injection sinking for the water decanter according to the second water injection time. After delaying, starting stirring; aeration control: in the aeration delay stage, jet stirring is continuously carried out; after the aeration is delayed, the aeration is carried out, and the frequency of a fan and the opening number of aeration branch pipes are controlled according to the ammonia nitrogen and DO data of the effluent; and (3) period adjustment: adjusting the aeration time and the stirring delay. The invention has the beneficial effects that: the labor intensity of operators is reduced, the effluent quality is improved, and the power consumption cost is reduced.

Description

Optimal control method for reducing energy consumption of ICEAS sewage treatment process

Technical Field

The invention relates to the technical field of sewage treatment, in particular to an optimal control method for reducing energy consumption of an ICEAS sewage treatment process.

Background

The SBR reaction tank is divided into two parts along the length direction by ICEAS (Intermitent Cycle Extended operation), wherein the front part is an unreacted zone, and the rear part is a main reaction zone. The pre-reaction zone has the function of adjusting water flow, and the main reaction zone is the main body of aeration and sedimentation. ICEAS is a continuous water inlet process, which feeds water not only during the reaction stage, but also during the precipitation and decantation stages. After the sewage enters the pre-reaction zone, the sewage enters the main reaction tank in a advection flow state through a connector at the bottom of the partition wall, and the intermittent aeration and sedimentation decanting are carried out in the main reaction tank to form an SBR reaction tank with continuous water inlet and intermittent water outlet, so that the water distribution is greatly simplified, and the operation is more flexible.

The conventional ICEAS process mainly comprises: A. in the aeration stage, an aeration system intermittently supplies oxygen to the reaction tank, at the moment, organic matters are biologically oxidized under the action of microorganisms, and simultaneously, ammonia nitrogen in sewage is nitrified and denitrified by the microorganisms to achieve the effect of denitrification; B. in the sedimentation stage, oxygen supply to the reaction tank is stopped, and the activated sludge descends in a static state to realize sludge-water separation; C. in the decanting stage, after the sludge is precipitated to a certain depth, the decanter system starts to work, and supernatant in the reaction tank is discharged. In the decanting process, because the sludge is settled at the bottom of the tank and has higher concentration, a sludge pump can be started according to needs to discharge the residual sludge into the sludge tank so as to keep certain active sludge concentration in the reactor. After the water decanting is finished, the next new period is started, aeration is started, and the process is repeated in cycles to finish the sewage treatment.

However, the conventional ICEAS is only time control, has no process control, is not high in intelligent degree, once the process control is needed, a large amount of time of workers is consumed for manual adjustment, and in actual operation, the time control cannot be timely adjusted according to the change of the inflow water quality, so that the energy conservation and consumption reduction are not facilitated.

Disclosure of Invention

In order to solve the problems that the traditional ICEAS process control needs to consume a great deal of energy of workers, the intelligent degree is not high, the operation mode is single, and the energy consumption is high, the invention provides an optimal control method for reducing the energy consumption of an ICEAS sewage treatment process, which is applied to an optimized ICEAS sewage treatment system;

the optimized ICEAS sewage treatment system comprises: the device comprises a jet valve, a circulating water pump and a time delay relay;

the jet valve and the circulating water pump carry out jet stirring to fully mix the mud and water in the biological pond, and the running process is free from reoxygenation and can play a role in backflow.

The water inlet end of one jet valve is connected to the biological pond through a pipeline, the water outlet end of the jet valve is connected to the water inlet end of a circulating water pump through a pipeline, the water outlet end of the circulating water pump is connected to the water inlet end of the jet valve of the pond through a pipeline, and the water outlet end of the jet valve is connected to the biological pond through a pipeline; a delay relay is added on a control circuit of the water inlet hoist to serve as a delay control device of the water inlet hoist; the aeration valve is an intelligent electric valve; each aeration valve is electrically connected with the system PLC respectively and is controlled by the PLC;

the optimal control method for reducing energy consumption of the ICEAS sewage treatment process specifically comprises the following steps:

s101: a precipitation stage: closing the water inlet opening and closing machine at the beginning of sedimentation, presetting valve closing time through an upper computer interface, opening the water inlet opening and closing machine when the valve closing time is up, and performing first water injection on the decanter according to the first water injection time to enable the decanter to sink so as to prepare for decanting; the valve closing time and the first water injection time are preset through an upper computer interface;

s102: decanting stage: when the drainage is started, under the action of an opening signal of the drainage valve, the delay relay starts to work, and after the water decanting delay time, the water inlet opening and closing machine is closed; when the water drainage is finished, the water inlet opening and closing machine starts to open water inlet under the action of an 'off' signal of the drain valve; wherein, the decanting delay time is preset through an upper computer interface;

s103: and (3) stirring: in the stirring delay time, performing secondary water injection on the decanter according to the secondary water injection time, so that a decanter hose sinks, and no sludge enters the decanter in a protection hose and an aeration stage; after the stirring delay time is over, opening a jet valve and a circulating water pump to start jet stirring; wherein, the stirring delay time and the second water injection time are preset through an upper computer interface;

s104: and (3) an aeration stage: continuously jetting and stirring in the aeration delay time; after the aeration delay time, closing the jet valve and the circulating water pump, opening the aeration valve and the fan to start aeration according to the aeration time, and controlling the opening number of the aeration branch pipes according to the ammonia nitrogen in the effluent;

s105: judging whether the ammonia nitrogen value of the effluent is in [ x-y, x + y ]; if yes, indicating that the water outlet is stable, directly returning to the step S101, and entering the next period; if not, indicating that the effluent is unstable, and going to step S106; wherein x is a preset warning value; y is a preset fluctuation range of the ammonia nitrogen value of the effluent;

s106: and (3) period adjustment: adjusting aeration time, fan frequency and stirring time;

and step S101 to step S106 are executed circularly to treat the sewage periodically.

Further, the upper computer is a WinCC upper computer. In the step S102, in the decanting stage, the PLC acquires a decanting warning liquid level, a ss warning value and an mlss warning value which are set by a worker through a WinCC upper computer; if any one of the three warning values is triggered in the drainage process, closing the drainage valve; otherwise, draining according to the decanting delay time.

Further, the optimized ICEAS sewage treatment system still includes: a sludge concentration meter, a Securie plate and a ss instrument; the sludge concentration meter is arranged at the lowest drainage liquid level near the decanter and is used for monitoring the sludge level; the Seitz disc is used for indicating the visibility of the water body; the ss instrument is used for indicating the clarity degree of the water body;

in the decanting stage, the upper computer interface displays the readings of the sludge concentration meter, the Securium disc and the ss instrument, a worker judges the required decanting depth by observing the readings of the sludge concentration meter, the Securium disc and the ss instrument, and then sets a decanting warning liquid level through the upper computer according to experience.

Further, the optimized ICEAS sewage treatment system comprises 4 aeration branch pipes which are respectively a 1# branch pipe, a 2# branch pipe, a 3# branch pipe and a 4# branch pipe; the fan is connected to the biological pond through 4 aeration branch pipes;

in step S104, the number of the aeration branch pipes is started; the method specifically comprises the following steps:

when the frequency of the fan is greater than or equal to 37Hz, all the aeration valves are fully opened, namely 4 aeration branch pipes are fully opened;

when the frequency of the fan is greater than or equal to 29Hz and less than or equal to 36Hz, three groups of aerator branch pipes including the 2# branch pipe, the 3# branch pipe and the 4# branch pipe are opened, and the 1# branch pipe is closed;

when the frequency of the fan is more than or equal to 23Hz and less than or equal to 28Hz, the two groups of aeration branch pipes of the No. 2 branch pipe and the No. 3 branch pipe are opened, and the No. 1 branch pipe and the No. 4 branch pipe are closed.

Further, in step S106, the aeration time and the stirring time are adjusted by the specific method:

the aeration time and the stirring time are changed by adjusting the aeration delay time, and if the aeration delay time is increased, the stirring time is correspondingly increased, and the aeration time is correspondingly reduced; otherwise, the same principle is adopted;

the aeration delay time adjusting method comprises the following steps:

s201: presetting a coarse adjustment interval and a fine adjustment interval, wherein the coarse adjustment interval and the fine adjustment interval are respectively provided with an adjustment step length;

s202: judging whether the difference value of the real-time value of the ammonia nitrogen in the effluent and a preset warning value is greater than 0; if yes, go to step S203; otherwise, go to step S204;

s203: reducing the aeration delay time: if the absolute value of the difference value is positioned in the coarse adjustment interval, the aeration delay time is reduced by the adjustment step length corresponding to the coarse adjustment interval; if the absolute value of the difference value is positioned in the fine adjustment interval, the aeration delay time is reduced by the adjustment step length corresponding to the fine adjustment interval; go to step S205;

s204: increasing the aeration delay time; if the absolute value of the difference value is positioned in the coarse adjustment interval, the aeration delay time is increased by the adjustment step length corresponding to the coarse adjustment interval; if the absolute value of the difference value is positioned in the fine adjustment interval, the aeration delay time is increased by the adjustment step length corresponding to the fine adjustment interval; go to step S205;

s205: and finishing the adjustment.

Further, the fan frequency is adjusted, and the specific method comprises the following steps: if the ammonia nitrogen value of the effluent is greater than a preset warning value in a factory area, finely adjusting the frequency of the fan to increase; otherwise, the number is reduced; the method specifically comprises the following steps:

when the ammonia nitrogen of the effluent is below the warning value, finely adjusting the frequency of the fan to be reduced by 2Hz-3Hz, and if the ammonia nitrogen of the effluent in the next period is reduced, reducing the frequency of the fan by 1Hz-2Hz until the ammonia nitrogen is stable; otherwise, the fan frequency is increased according to the rule.

The technical scheme provided by the invention has the beneficial effects that: the technical scheme provided by the invention has the following two advantages:

1) reduce operating personnel intensity of labour: the prior control system needs to manually adjust the operation frequency of the fan and the on-off state of the valve on site frequently, and then adjusts the decanting water liquid level through manually recorded data.

2) The power consumption cost is reduced: the unit consumption of each ton of water and electricity is expected to be reduced by 5% compared with that before the development (the annual average ton of water and electricity consumption of the traditional ICEAS is about 0.118, and the annual ton of water and electricity consumption is expected to be about 0.108 by adopting the technical scheme provided by the application), and the electricity charge can be saved by about 9 ten thousand yuan per year. If the energy-saving and consumption-reducing device can be popularized and applied, the energy-saving and consumption-reducing effects can be improved.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a block diagram of an optimized ICEAS wastewater treatment system;

FIG. 2 is a flow chart of an optimal control method for reducing energy consumption of an ICEAS sewage treatment process in the embodiment of the invention.

Detailed Description

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

The embodiment of the invention provides an optimal control method for reducing energy consumption of an ICEAS sewage treatment process; the method is applied to an optimized ICEAS sewage treatment system;

referring to FIG. 1, FIG. 1 is a block diagram of an optimized ICEAS wastewater treatment system; the optimized ICEAS sewage treatment system comprises: the biological sewage treatment system comprises a water inlet opening and closing machine 1, a flow pushing device 9, a fan 3, a biological pond 8, a decanter 7, a drain valve 6, a PLC (not shown in the figure) and an upper computer (not shown in the figure); the water outlet end of the water inlet hoist 1 is connected to the water inlet end of the flow impeller 9 through a pipeline, and the water outlet end of the flow impeller 9 is connected to the biological pond 8 through a pipeline; the fan 3 is connected to the biological pond 8 through a plurality of aeration branch pipes, and each aeration branch pipe is provided with an aeration valve 2; the water inlet end of the decanter 7 is connected to the biological tank 8 through a pipeline, and the water outlet end is connected to the drain valve 6 through a pipeline; the water inlet hoist 1, the flow impeller 9, the fan 3, the decanter 7 and the drain valve 6 are all controlled by a PLC (programmable logic controller), and an upper computer is communicated with the PLC so as to set related control parameters through the upper computer;

the method is characterized in that: the optimized ICEAS sewage treatment system further comprises: a jet valve 4, a circulating water pump 5 and a delay relay (not shown in the figure);

the number of the jet valves 4 is two, the water inlet end of one jet valve 4 is connected to the biological pond 8 through a pipeline, the water outlet end of the other jet valve 4 is connected to the water inlet end of the circulating water pump 5 through a pipeline, the water outlet end of the circulating water pump 5 is connected to the water inlet end of the other jet valve 4 through a pipeline, and the water outlet end of the other jet valve 4 is connected to the biological pond 8 through a pipeline;

a delay relay is added on a control circuit of the water inlet hoist 1 to serve as a delay control device of the water inlet hoist 1;

the aeration valve 2 is an electric valve (or a diamond valve with an opening); and each aeration valve 2 is electrically connected with the PLC respectively and is controlled by the PLC.

Referring to fig. 2, fig. 2 is a flowchart of an optimal control method for reducing energy consumption in an icosa wastewater treatment process in an embodiment of the present invention, which specifically includes the following steps:

s104: and (3) an aeration stage: continuously jetting and stirring in the time delay of aeration; after the aeration delay time, closing the jet valve and the circulating water pump, opening the aeration valve and the fan to start aeration according to the aeration time, and controlling the opening number of the aeration branch pipes according to the ammonia nitrogen in the effluent;

The upper computer is a WinCC upper computer. In the step S102, in the decanting stage, the PLC acquires a decanting warning liquid level, a ss warning value and an mlss warning value which are set by a worker through a WinCC upper computer; if any one of the three warning values is triggered in the drainage process, closing the drainage valve 6; otherwise, draining according to the decanting delay time.

The optimized ICEAS sewage treatment system also comprises: a sludge concentration meter, a Securie plate and a ss instrument; the sludge concentration meter is arranged at the lowest drainage liquid level near the decanter and is used for monitoring the sludge level, when the aerator is finished, the reading of the sludge concentration meter is reduced from 4000mg/l to 100mg/l, and when the reading of the sludge concentration meter is below 100mg/l in the drainage stage, the sludge level is safe for drainage; the Seitz disc is used for indicating the visibility of a water body, and the higher the visibility is, the clearer the water quality is; the ss instrument is used for indicating the clarity degree of the water body, the ss is less than 20mg/l, the water is clear, the visibility can be sampled on site, the sampled water is input into a control program, and the decanting depth is controlled by the system through the relation among the three instruments and according to the water outlet data; in the decanting stage, the upper computer interface displays the readings of the sludge concentration meter, the Securinega disc and the ss instrument, a worker judges the required decanting depth by observing the readings of the sludge concentration meter, the Securinega disc and the ss instrument, and then sets a decanting warning liquid level through the upper computer;

the decanting depth is controlled by the starting number and the water injection time of the water injection pumps, and the time and the starting number of the pumps can be selected and set by an upper computer and then are controlled by a PLC. Therefore, the interference of water inflow can be reduced, the drainage quality is ensured, the drainage depth is convenient to improve, the liquid level in the aeration stage is reduced, and the energy consumption of the fan 3 is reduced.

The optimized ICEAS sewage treatment system comprises 4 aeration branch pipes which are respectively a 1# branch pipe, a 2# branch pipe, a 3# branch pipe and a 4# branch pipe; the fan is connected to the biological pond through 4 aeration branch pipes; in step S104, the number of aeration branch pipes is opened in the aeration stage; the method specifically comprises the following steps:

In step S106, the aeration time and the stirring time are adjusted, and the specific method is as follows:

the aeration delay time adjusting method comprises the following steps:

s205: and finishing the adjustment.

The method for adjusting the frequency of the fan comprises the following steps: if the ammonia nitrogen value of the effluent is greater than a preset warning value in a factory area, finely adjusting the frequency of the fan to increase; otherwise, the number is reduced;

the method specifically comprises the following steps: with the effluent ammonia Nitrogen (NH) ₃ N) is used as a main part, DO is used as an auxiliary part, and the frequency of the fan and the opening and closing quantity of the aeration branch pipes are adjusted by combining the actual operation condition. When the ammonia nitrogen of the outlet water is below the warning value of the plant area, finely adjusting the frequency of the fan to be reduced by 2Hz-3Hz (specifically, the frequency can be set according to the requirement), and if the ammonia nitrogen of the outlet water in the next period is reduced, reducing the frequency of the fan by 1Hz-2Hz (specifically, the frequency can be set according to the requirement) until the ammonia nitrogen is stable; otherwise, the running frequency of the fan is increased.

The invention has the beneficial effects that: the technical scheme provided by the invention has the following two advantages:

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. An optimization control method for reducing energy consumption of an ICEAS sewage treatment process is applied to an optimized ICEAS sewage treatment system; the method is characterized in that: the optimized ICEAS sewage treatment system further comprises: the device comprises a jet valve, a circulating water pump and a time delay relay;

the water inlet end of one jet valve is connected to the biological pond through a pipeline, the water outlet end of the jet valve is connected to the water inlet end of the circulating water pump through a pipeline, the water outlet end of the circulating water pump is connected to the water inlet end of the other jet valve of the biological pond through a pipeline, and the water outlet end of the jet valve is connected to the biological pond through a pipeline;

a delay relay is added on a control circuit of the water inlet hoist as a delay control device of the water inlet hoist;

the aeration valve is an electric valve; each aeration valve is electrically connected with the system PLC respectively and is controlled by the PLC;

s101: a precipitation stage: when the sedimentation starts, closing the water inlet opening and closing machine, presetting valve closing time through an upper computer interface, opening the water inlet opening and closing machine when the valve closing time is reached, and performing first water injection on the decanter according to the first water injection time to enable the decanter to sink so as to prepare for decanting; the valve closing time and the first water injection time are preset through an upper computer interface;

s102: decanting stage: when the drainage is started, under the action of an opening signal of the drainage valve, the delay relay starts to work, and after the water decanting delay time, the water inlet opening and closing machine is closed; when the drainage is finished, the water inlet opening and closing machine starts to open water inlet under the action of an 'off' signal of the drain valve; wherein, the decanting delay time is preset through an upper computer interface;

s106: and (3) period adjustment: adjusting the aeration time, the stirring time and the frequency of a fan;

in the step S106, the aeration time and the stirring time are adjusted, and the specific method includes:

the aeration delay time adjusting method comprises the following steps:

s201: presetting a coarse adjustment interval and a fine adjustment interval, wherein the coarse adjustment interval and the fine adjustment interval are respectively corresponding to adjustment step lengths;

s205: finishing the adjustment;

2. The optimal control method for reducing energy consumption of the ICEAS sewage treatment process as claimed in claim 1, wherein the optimal control method comprises the following steps: the upper computer is a WinCC upper computer.

3. The optimal control method for reducing energy consumption of the ICEAS sewage treatment process as claimed in claim 2, wherein: in the step S102, in the decanting stage, the PLC acquires a decanting warning liquid level, a ss warning value and an mlss warning value which are set by a worker through a WinCC upper computer; if any one of the three warning values is triggered in the drainage process, closing the drainage valve; otherwise, draining according to the decanting delay time.

4. The optimal control method for reducing energy consumption of the ICEAS sewage treatment process as claimed in claim 1, wherein the optimal control method comprises the following steps: the optimized ICEAS sewage treatment system also comprises: a sludge concentration meter, a Securie plate and a ss instrument; the sludge concentration meter is arranged at the lowest drainage liquid level near the decanter and is used for monitoring the sludge level; the Seitz disc is used for indicating the visibility of the water body; the ss instrument is used for indicating the clarity degree of the water body;

5. The optimal control method for reducing energy consumption of the ICEAS sewage treatment process as claimed in claim 1, wherein the optimal control method comprises the following steps: the optimized ICEAS sewage treatment system comprises 4 aeration branch pipes which are respectively a 1# branch pipe, a 2# branch pipe, a 3# branch pipe and a 4# branch pipe; the fan is connected to the biological pond through 4 aeration branch pipes;

in the step S104, the opening number of the aeration branch pipes is controlled according to the ammonia nitrogen of the effluent; the method specifically comprises the following steps:

6. The optimal control method for reducing energy consumption of the ICEAS sewage treatment process as claimed in claim 1, wherein the optimal control method comprises the following steps: the method for adjusting the frequency of the fan comprises the following steps: if the ammonia nitrogen value of the effluent is greater than a preset warning value in a factory area, finely adjusting the frequency of the fan to increase; otherwise, the number is reduced; the method specifically comprises the following steps: