Comparison of metal magnetic memory diagnostic schemes

Compared with other conventional non-destructive testing techniques, the metal magnetic memory testing technology has the most remarkable features: no need to expand the balance hole of the 13th stage impeller before the test, and the balance holes of the 14th and 15th stage impellers, 7th, 9th, 10th The diaphragm diaphragm has a reduced width and improved axial thrust. Solution: (1) Redesign and manufacture of nozzles, partitions, buckets and final four-stage impellers in all stages of the flow section. (2) After the transformation, the nameplate output of the electric load is increased from 50MW to 60MW, and the heat consumption of the pure coagulation condition reaches 99601kJkWh. (3) Constraints of transformation: the thermal parameters are unchanged, the rated inlet and outlet and extraction parameters are unchanged; the thermal system is unchanged, the interface position and parameters of each regenerative extraction port remain unchanged; the base of the unit is connected with the turbine The size and position of the system are unchanged.

Conclusion: Through the comprehensive comparison of the three programs, it is considered that the third option is excellent. On the one hand, this solution can completely solve the problem of insufficient design strength of the last four stages of blades, improve the safety and reliability of the unit, and on the other hand, it has good economy. Although the investment is large, the recovery period is short and the annual profit is large. Therefore, the plant recommends using the third option to renovate the unit.

Table 1 Project plan 1, plan 2, plan 3 transformation costs: the 13th level impeller blade manufacturing cost is about 300,000, the 13th level baffle manufacturing cost is about 140,000, the repair cost is about 150,000, the last four-stage impeller blade manufacturing fee is about 1.65 million, a total of three partitions manufacturing costs of about 500,000, the final four-stage impeller blade manufacturing costs of about 1.65 million, the remaining 12-stage moving blade manufacturing costs of 800,000, repair costs of about 100,000, a total of 13 payouts manufacturing costs of about 195 10,000, two nozzles manufacturing costs of about 320,000, repair costs of about 250,000, design costs of about 300,000, a total of 592.25 million 5.27 million. The production cycle is 6 months, 6 months and 10 months. The repair cycle is 10 days, 15 days, 25 days. Perform any pre-treatment on the surface of the tested component (including the power station fastening bolt); do not need to pre-charge the object to be inspected; can quickly find the stress concentration zone of the component and the position and orientation of the defect (ie, find the early fatigue of the component) The damage is).