Urban sewage plant aeration tank dissolved oxygen stable intelligent control method and device

Abstract

The invention discloses a stable intelligent control method and a device of dissolved oxygen in an aeration tank of an urban wastewater treatment plant in a technical field of environment protection. An air supply loop of the aeration tank is connected with a fan and air supply main pipes. An aeration area is divided into four sub-areas, each of which adopts a separate air supply main pipe for air supplying; each air supply main pipe has an electric valve; each sub-area has a determinator of dissolved oxygen; the system can realize the intelligent feedback control of the dissolved oxygen and the electric valve on the programmable controller. The stable intelligent control method and the device suitable for the water quality and amount change of water entering the urban wastewater treatment plant and keep stable concentration of dissolved oxygen in the aeration tank. According to the changing rule of measured value of gas flowmeters arranged on each air supply main pipe, the comprehensive result of water quality and amount change of the water entering the wastewater treatment plant can be reflected, thus decreasing the energy consumption of aeration cells and saving the operation expense of the aeration cells.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to an intelligent control method and device for stabilizing dissolved oxygen in an aeration tank of an urban sewage plant. Background technique [0002] In the current sewage treatment field, the activated sludge method is one of the most widely used treatment processes. The process takes the aeration tank as the core treatment equipment. Under the action of aeration, the mixed liquid in the aeration tank gets enough oxygen and makes the living The microorganisms on the activated sludge decompose the soluble organic matter to purify the sewage. Among them, the concentration of dissolved oxygen in the aeration tank directly affects the removal efficiency of organic matter, and affects the growth of activated sludge in the process of activated sludge sewage treatment, and is also an important factor affecting operating costs and effluent water quality, so ...

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Problems solved by technology

The disadvantages of the above-mentioned prior art control method are: first, due to the time delay, that is, it takes a period of time from the adjustment of the valve opening to the change of the measured value of dissolved oxygen in the pool, causing the adjustment of dissolved oxygen to lag behind, thereby causing fluctuations; The existing regulating valves are generally non-linear, and the aeration rate changes non-linearly with the opening of the valve, and the simple PID control is easy to cause the oscillation of the dissolved oxygen concentration; the third is that the effect of manual control is closely related to the experience of the operator. relationship, and the reliability of the control is relatively low, which is prone to over-regulation, resulting in fluctuations in dissolved oxygen concentration; fourth, the aeration energy consumption of the above-mentioned method is high, which is because the fluctuation range of the dissolved oxygen concentration under the above-mentioned method is relatively large. Large, in order to ensure the safe operation of the process, the dissolved oxygen setting value of the system can only be maintained at a relatively high value, maintaining excessive redundancy and resulting in an increase in aeration volume, thereby increasing the energy consumption of the aeration unit : Fifth, the fluctuation range of dissolved oxygen concentration will affect the growth and reproduction of microorganisms in the aeration tank, which will interfere with the operation of the sewage treatment process, thereby affecting the quality of the effluent water

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