Improvement and Effect Analysis of Steam Turbine
After the air compressor unit equipped with the methanol plant is installed in the air compressor unit, it is in a low load (75% to 80%) operation state for a long period of time. The main reason is that there is a problem with the drive steam turbine of the air compressor unit. The performance of the front radial bearing is high when the steam turbine is running, the temperature of the thrust bearing main push tile is high, and the steam seal leakage is large, which causes the unit speed to rise, which affects the air intake of the air compressor. The steam turbine inlet parameters of the unit are 10.0 MPa and 520 °C, and the front end bearing is designed as a joint bearing; the front section steam seal is designed as a general comb tooth seal (the original spring piece on the back, then changed to a spring), and there are 7 sets of steam seals. After the first three sets of steam seals, some of the leaked steam enters the 4.0 MPa extraction pipe network, and the rest passes through the two sets of steam seals as the shaft seal steam on the exhaust side. When it was overhauled in May 2007, it was found that the comb tooth seal was skewed and the gap between the rotor and the rotor was too large, there was a crack on the steam seal, and the elasticity of the steam seal spring was lowered. In view of the existing problems, the actual operation data and design drawings of the unit are analyzed and confirmed on the spot. The problems of the air compressor turbine are solved from two aspects: 1Using the device overhaul opportunity to solve the high temperature of the bearing of the air compressor itself. The steam seal has large air leakage and no problem in the speed; 2 perfect the operation of the air compressor/supercharger unit. 2 Technical changes in steam turbine overhaul in 2007 2.1 The solution to the high temperature of the thrust bearing main thrust tile Take the method of increasing the oil supply amount of the main thrust dam, taking into account the special design of the thrust and radial bearing oil supply mode, the actual situation that the thrust bearing and the radial bearing oil supply are mutually restrained, and take according to the actual calculation. The following specific measures: 1) The thrust oil bearing main thrust tile 2 oil supply holes are reamed from the standard 16 mm to the standard 16.5 mm to increase the main push tile oil supply. 2) The two oil supply holes of the thrust bearing auxiliary thrust tile are reduced from the standard 15 mm to the standard 14 mm to indirectly increase the oil supply amount of the main push tile. 3) According to the area change of the main thrust dam after the oil is reamed, correspondingly the upper oil return hole of the upper part of the damper ring is close to the main thrust tile side and then re-expanded by 2 holes, from the quasi-10mm reaming to the standard 11mm. 2.2 The solution to the large leakage of the steam seal and the failure of the speed According to the actual failure of the air compressor steam turbine overhaul, the steam seal spring is seriously ineffective, and the two-stage steam seal at the front end of the steam turbine is exposed to the axial pressure and has a long crack. The following measures are taken: 1) Replace the steam Sealed spring, spring material is Inconel 718. 2) All steam seals are opened between the front end of the steam turbine and the high and medium pressure sections, and steam is introduced to the steam seal spring side to compensate for the pressure on the side of the steam seal spring. From the end face of the steam seal facing the direction of steam leakage, first open 90° and perpendicular to each other, 3 mm and 2 mm holes. 3) Move the turbine front bearing housing to the east by 0.40 mm, try to ensure that the turbine rotor and cylinder concentricity meet the requirements, and reduce the problem of excessive gap difference between the east and the west. 4) Check the restriction orifice plate on the steam seal line to clear the blockage to ensure that the pipeline is drained and drained when driving. 2.3 Other repair contents 1) According to the actual situation that the lower one tile has slight defects after the front radial bearing is disassembled, the side tile and the tile are interchanged, and the platinum resistance temperature measurement pre-buried hole is reopened on the tile. 2) Increase the flow rate of the turbine condensate pump outlet and replace the air compressor inlet guide vane actuator. 2.4 Measures to optimize the operation of air compressor/supercharger unit after driving 1) Reduce the air venting of the anti-surge valve at the outlet of the air compressor and the air return flow of the anti-surge valve of the supercharger. 2) According to the effect of steam seal technical reform, properly increase the steam extraction amount of the air compressor and reduce the amount of condensate to reduce the temperature of the turbine thrust bearing. 3 large repair unit operation effect After the overhaul unit operation data, it can be seen that the steam consumption of the unit after the technical transformation is significantly reduced (the main steam intake of the steam turbine at the air compressor before the technical transformation is 100000110000 m 3 /h is 190.0~194.2 t/h, The steam volume is 82~86 t/h), the temperature of the thrust bearing drops significantly (formerly 114～115.5°C), and the air volume sent by the air compressor to the subsequent device increases (currently 142000m 3 / h, 95% load) . The actual operation results show that the boiler with 220 t / h steam can meet the operation requirements of the air compressor unit with 100% load, and if the temperature of the front radial bearing can be continuously reduced, the speed can be increased, so that the air volume can continue. increase. 4 pairs of solutions to solve the high temperature of the front radial bearing of the steam turbine The high temperature of the front radial bearing of the steam turbine was observed to be related to the load change. The radial bearing temperature is related to the oil temperature, the rotational speed and the load on the radial bearing, which is no exception to the turbine front radial bearing temperature. The radial load experienced by the front radial bearing is the vector sum of the radial force generated by the nozzle from the nozzle to produce a radial force on the rotor that is half (approximately) the weight of the rotor. The temperature of the front radial bearing of the steam turbine is sensitive to the change of steam inlet (load) and the change of the steam speed of the steam turbine. This fully demonstrates that the radial flow of the steam flow from the nozzle to the direction of the rotor cannot be ignored. The means to eliminate or reduce this radial force is generally to change the position of the governing valve head because the different nozzle inlet sequences have a large effect on the radial force. After the valve head is exchanged, the direction of the radial force acting on the rotor changes, and the direction is upwards, so that the combined force of the radial force generated by the steam flow on the radial bearing and the gravity of the rotor is reduced, which is beneficial to reduce the front diameter. To the bearing temperature. In fact, high-power steam turbine generator sets in the power generation industry have precedents that have successfully reduced the temperature of the front radial bearings. The sale of Bole Machinery is increasing steadily in recent years with the launch of new EKII series "China Unique Producer, Central Locking Toggle" machine. There are obvious advantages in the injection industry under the guidance of leading product technology strategy. The HK Series High Speed Machine has four advantages: a. energy saving; b. Efficiency c. precision d. high speed f. quiet Hk Injection Molding Machine,Energy Saving Injection Moulding Machine,Nissei Injection Molding Machine,Bole Injection Machine,Plastic Fork Knife Spoon Making Machine Ningbo Shuangma Machinery Industry Co., Ltd , https://www.bolemachinery.com