| Recirculating cooling water accounted for a large proportion of industrial water, usually for industrial water from 60% to 80%. Yet the recirculating cooling water of power industry accounted for more than 70% of the total amount of cooling water. In order to ensure the normal operation of recirculating cooling water system and industrial water saving, emission reduction and environmental pollution, choosing economical and practical water treatment methods to control the metal corrosion, scaling and mud stick is quite necessary. Add the efficient and environmentally friendly corrosion inhibitor has become the preferred choice.With the improvement of people’s environmental awareness, environmental protection has get more and more attention. The official promulgation of "ten water" points out the direction of water resources protection.The application of corrosion inhibitor play an important role in the protection of water resources. Nowadays, phosphorus reagent widely used in water treatment of thermal power plant. The excessive use will inevitably cause water pollution. Corrosion inhibitor without phosphorus and low phosphorus content is the future direction of development.This thesis research the scale inhibition performance disciplinarian through the study on single scale and corrosion inhibitor and the synergistic effect of scale inhibitor.Then select corrosion inhibitor formula GD-341 and GD-354 which is low phosphorus, high efficiency and economy by orthogonal test. The static scale inhibition rate of GD-341 and GD-354 were 90.0% and 96.9% respectively at 50 ppm. Of those, GD-341 is the low phosphorus corrosion inhibitor, phosphate (PO43-) content is 3.6%.Do the test of corrosion and scale inhibition performance, compatibility and stability on GD-341 and GD-354. The conclusions are as follows.(1) GD-341 and GD-354 can meet the requirements of concentration is more than 4.(2) The corrosion rate of brass and stainless steel is 0.0015-0.0020 mm/a and 0.0006-0.0009 mm/a respectively in the using concentration of 8 mg/L. Lower than the provisions of GB/T50050-2007 "code for desin of industrial recirculating cooling water treatment " in the rate of copper and copper alloy and stainless steel corrosion less than 0.0050 mm/a.(3) Dynamic simulation experiment research on GD-341 indicated that the corrosion rate of stainless steel and brass is 0.0006 mm/a and 0.001-0.0042 mm/a respectively in the condition of dosage (according to supplement water calculation) 5 mg/L. Annual fouling resistance value is 0.765×10-4 m2K/W and the adhesion rate is 12.78 mcm, which have achieved the desin code requirements of GB50050-2007 which stipulate the corrosion rate of stainless steel and copper<0.005 mm/a, annual fouling resistance value<3.44×10-4 m2K/W and adhesion rate<15 mcm.(4) It has good compatibility between medicament and the oxidized or nonoxidizing biocide.(5) The physicochemical indexes and corrosion inhibition performance have no obvious change after cold and thermal stability test.In addition, study on application in thermal power plant of the reagent have been made. The relevant quality standards of pharmaceutical have been formulated. The result of corresponding products index determination show that GD-341, GD-354 have reached the standards of the power industry (DL/T 806-2013) requirements specified in the acceptance criteria. Moreover,the technical scheme have been made according to the process parameters of recirculating cooling water system of Yunfu power plant (C plant). |
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