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2022-07-24
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Mechanical and electrical construction technical knowledge point 20: main equipment of steam turbine and generator? Today, I have sorted out the mechanical and electrical construction technical knowledge point 20 of the secondary constructor: main equipment of steam turbine and generator. I hope it can help you

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knowledge point 20: technical requirements for the installation of main equipment of steam turbine and generator

[frequency index] ★★

[examination point presentation]

I. installation of steam turbine in power station

1 Key points of LP cylinder assembly installation technology

(1) the benchmark for cylinder centering during assembly can be laser, steel wire drawing, dummy shaft, rotor, etc. at present, the steel wire drawing method is mostly used. That is, after the rear section (motor side) of the low-pressure outer lower casing and the front section (steam side) of the low-pressure outer lower casing are in place respectively, and the level and elevation are adjusted, the longitudinal steel wire can be pulled to adjust the steam seal depression or bearing oil baffle depression, and the dimensions of the depression and the steel wire in the left, right and lower directions shall be measured to meet the requirements

(2) LP outer upper cylinder assembly includes: trial assembly to check the clearance between horizontal and vertical joint surfaces, and formal assembly after meeting the requirements

(3) LP inner cylinder assembly includes: after LP inner cylinder is in place and aligned and diaphragm is adjusted, LP rotor is hoisted into cylinder and positioned, and then flow passage clearance is adjusted

2. Alignment of shafting coupling center

(1) alignment of shafting coupling center mainly refers to alignment of high and medium pressure coupling center, medium and low pressure coupling center, low pressure coupling center and low pressure rotor electric rotor coupling center

(2) describe the application precautions and maintenance details of the fatigue testing machine under 1 when the shaft system makes the friction coefficient stable under strict regulations: when aligning the wheel center within the average deviation range from heavy impact during the application process and handling process, first take the low-pressure rotor as the benchmark; Secondly, the alignment of the wheel is usually adjusted by filling the full solid cylinder and condenser to the simulated running state; Thirdly, the opening and height difference of each pair of wheels during alignment shall have reserved values; Finally, the wheel center shall be rechecked and aligned for many times at different stages

II. Generator installation

(I) generator installation procedure

generator equipment installation procedure: stator in place → stator and rotor hydrostatic test → generator threading rotor → hydrogen cooler installation → end cover, bearing, sealing pad adjustment and installation → exciter installation → wheel alignment and connection → overall air tightness test, etc

(II) key points of generator installation technology

1 Key points of generator stator hoisting technology

stator hoisting: generally, two cranes in the main power house are used, and two temporary trotters are added to the crane run, and then the lifting beam is prepared to lift the stator at the same time. The lifting stator is about 1m above the ground. Try braking for 2-3 times, and start the normal lifting after confirming that the braking is good

2. Key points of generator rotor installation technology

(1) common methods for generator rotor installation include slide way method, shaft connection method, using rear bearing seat as balance weight, using two sports cars, etc.

(2) separate air tightness test shall be conducted before generator rotor installation. After the leakage is eliminated, the air leakage test shall be conducted again, and the test pressure and allowable air leakage shall comply with the regulations of the manufacturer

[shorthand comments] this knowledge point focuses on mastering the contents, mainly mastering the alignment of Turbine Shafting wheel center and the installation of generator rotor, which is easy to appear in the form of multiple-choice questions

[classic examples]

1 When the low-pressure outer lower cylinder of steam turbine is combined, the benchmark for cylinder centering is currently mostly ()

a. laser method

b. steel wire drawing method

c. dummy shaft method

d. rotor method

[answer] b

[analysis] this question examines the technical requirements for the installation of the main equipment of the steam turbine generator system. The benchmark for cylinder centering during assembly can be laser, steel wire drawing, dummy shaft, rotor, etc. At present, the steel wire drawing method is mostly used

2. The installation process requirements for generator rotor are ()

a. separate air tightness test shall be carried out before rotor installation

b. air leakage test

c. rotor installation shall be carried out before the completion of maintenance work

d. it can only be carried out after obtaining a visa

e. rotor installation shall be carried out by crane lifting method

[answer] abd

[analysis] the two parties involved in this topic shall continue to measure 1 point at the center of all samples in the United Nations and Asia. The European Conference, the Shanghai Cooperation Organization Strengthening coordination and cooperation within the framework of CICA and other international organizations is the technical requirement for the installation of main generator equipment. Separate air tightness test shall be conducted before the installation of generator rotor. After the leakage is eliminated, the air leakage test shall be conducted again, and the test pressure and allowable air leakage shall comply with the regulations of the manufacturer. The installation of the generator rotor must be carried out after the completion of the maintenance (such as support, Jack, sling and other service preparations), electrical and thermal instruments, and the final cleaning and inspection of the stator and rotor must be carried out together with relevant personnel to ensure that their interior is clean and free of any sundries, and can only be carried out after obtaining a visa

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