The production process of thermal power plants can roughly divide the production links of the whole plant into five parts: machine, furnace, electricity, chemical and heat. Among them, raw materials or working fluids such as coal, water, steam and chemicals are involved in the production process.
Figure 1: Diagram of the hydrodynamic cycle of a thermal power plant
The deionized water used in the hydraulic cycle of thermal power plants has a strict preparation process, in which TOC is strictly controlled as a control index. The preparation principle is generally as follows: the raw water is converted into deionized water with qualified quality for boilers and chemical production through physical action, so as to reduce the corrosion and scaling of the boiler and furnace thermal equipment, and ensure long-term safe and economical operation. The hydraulic workshop of thermal power plants usually uses tap water as raw water, and removes suspended solids, calcium and magnesium in the water through high-efficiency fiber filters, yin and yang beds, mixed beds and EDI equipment. Sodium and other cations, chloride, sulfate, carbonate, silicate and other anions. After this series of steps, the effluent is primary deionized water.
ONYX TOC degradation equipment effectively degrades TOC in water through UV direct photolysis and hydroxyl radical oxidation to improve water quality standards.
A) UV Direct Photolysis——Organic matter in water absorbs ultraviolet light quantum to form excited state
B) hydroxyl radical oxidation
For the following sterilization pain points of cooling water and boiler make-up water in the thermal power plant industry:
1) Disinfection substances such as chlorine have to be added, which is not environmentally friendly.
2) It is difficult to accurately control the dosage of the drug (the reducing agent is less residual chlorine to oxidize the RO membrane; the reducing agent is too much to supplement the nutrients for the microorganisms), and the accumulated chlorine-resistant bacteria will quickly breed and multiply on the membrane for a long time.
3) Some microorganisms are difficult to kill with chemicals (such as iron bacteria, sulfate reducing bacteria, etc., which will cause pipeline corrosion).
4) There are large organisms (shellfish) and microbial fouling in pipes, heat exchangers, etc.
5) If the water source changes, the chemical plan needs to be adjusted frequently according to different water quality, and the operation and maintenance conditions are not good.
6) After adding a large amount of sodium hypochlorite in the workshop, the irritating smell is strong, which pollutes and corrodes the equipment.
ONYX targeted the use of medium-pressure broad-spectrum fungicides and higher bactericidal doses to deal with:
1) Ultraviolet light irradiation has a good bactericidal effect on a variety of bacteria in circulating water. When the UV irradiation time is 2 s, the UV dose is 40mJ/cm2, the total iron in the circulating water is less than 0.5 mg/L, the turbidity is less than 10 mg/L, and the circulating water through the UV system accounts for 50% of the total flow, the heterotrophic in water The killing rate of bacteria is more than 99.9%.
2) The results of the dynamic simulation test show that the number of heterotrophic bacteria is less than 1×105 mL-1 after 60% of the circulating water is treated with ultraviolet light.
Post time: Sep-16-2022