汽轮发电机样本英文QFW SERIES STEAM TURBINE GENERATOR.doc

NANYANG EXPLOSION PROTECTION GROUP CO., LTD.QFW SERIES STEAM TURBINE GENERATORS1. GENERALQFW series brushless turbine generators developed by CNE are new and high-tech products which combine the technology of explosion protection, electronics, auto controlling and generator. As a new generatoin of replacement of basic QF series steam turbine generators in China, such generators are widely used in fields of petrol, chemical, fertilizer, steel, sugar, and cement, where residual heat or pressure is recovered to produce electricity.The generators are designed with advanced electrical, mechanical, and vibration analyzing software; and new technology, new material, new manufacturing method are greatly adopted in the design, plus the advanced concept and experiences of worldwide generator manufacturing, which make the generators to have advantages of high compact construction, light weight, high efficiency, low noise level & vibration, reliable operation, good appreance, convenient maintenance and long service life cycle. The generators can be coupled with steam turbines for all kinds of application, such as blast furnace TRT, cement kiln heat recovery turbine, natural gas, coal gas, waste burning, terrestrial heat, or for plant power generation. It is not only the solution for energy conservation but also remarkable economic benefits to users.The generators are design with brushless excitation system but without slip ring system, through which there will be no disturbance on the wireless wave, avoiding the various faults due to bad contact when slip rings are worn down by friction, and hence the machines reliability is increased and the maintenance work load is reduced. The generators have a wide application, some times could be operated in explosive hazardous location because there is no sparking coming out during running. Consisting of brushless sysem of main, pilot exciter & PMG, this geneator design can provide a quick and strong excitation voltage when the power system voltage is low comparing with the traditional static excitation, since the excitation current is produced by PMG which is free of impact from the system voltage. Therefore the reliability of power system and generator sets is greatly is enhanced.The QFW series generator includes 2 pole and 4 pole design, which is targeted for Chinese domestic and oversea market respectively.QFW-2P 3000-60000KW, voltage 6.3kV or 10.5kV, frequency 50Hz, enclosure protection IP44;QFW-4P 3000-50000KW, voltage 6.3kV or 10.5kV, frequency 50Hz, enclosure protection IP54;2. STANDARDS APPLICABLEThe generators is designed and built as per GB/T7064, Technical Requirements for Turbine Synchronous Electrical Machines, which is identical or much stricter than IEC34-3 (1998), as well as the latest revision of the following specifications for generator design and manufacturing:1) GB75, Basic Technical Requirements for Rotating Electrical Machines;2) GB/T7064, Technical Requirements for Turbine Synchronous Electrical Machines;3) GB/T1029, Test Methods for Three Phase Synchronous Electrical Machines;4) GB/T7409.3, Basic Technical Requirements for Large and Middle Size Synchronous Generator Excitation System;5) JB/T7784, AC Exciter for Turbine Synchronous Generator.3. DESIGNATIONQF W- 15- 2 Pole (MW) Brushless excitation Steam turbine4. 2 POLE GENERATORSQFW 2P generator was developed based on QF series CACA design, with advanced design and manufacturing technology from oversea companies. It has a better construction, easier for connection, installation, operation and maintenance, thus greatly improves the uninterrupted operation time while limits the power system failure. The construction features of 2P generators are as the following:4.1 GeneralThe generator is double layer construction. The cooling system is a closed cycling ventilation with coolers mounted underneath. The single layer arrangement is also available, with cooler mounted on the top.The generator stator, bearing pedestals are all mounted on the base plate which consists of several pieces that to be completed together, then leveled, and fixed on the foundation by bolts in the power plant. To adjust the mounting dimensions, sliding plates is provided for base plate, and shims for stator, end shields, bearing pedestals. A solid base plate is also available if a quick installation is required.To avoid harmful shaft current, insulation between bearing and ground at non driven end is furnished, and earthing brushes fitted on the turbine end.4.2 Stator designThe generator stator consists of frame, core and winding. The frame is made of steel plates, light but strong. Inside frame, it is divided into many air blocks in axial direction. The end shields at both ends are made of cast iron, featured with inspection window and air tight facilities. The bottom cover is of welded steel plates, together with the end shields it is bolted on the stator frame. An insulation plate is fitted for the stator leads connection under the bottom cover at exciter side. The stator core is made from high quality silicon steels covered on both sides with solid insulation, sectioned and pressed by dove tail bars around the core that is further clamped tightly on the supporting bars fixed on the frame. Between every two sections, I shape bars are used to form the radial ventilation paths.The stator coil is half coil, made from multi-strand bare copper wrapped with fibre glass paper (some of them with interposing coil). The insulation class is F, mica paper tapped and hot pressed. The winding ends are wrapped by fibre rope and braced tightly, so that the power unit has a greatly improved short circuit impact resistance.4.3 Rotor designThe rotor shaft is made of a solid steel alloy, slotted at radial direction for the rotor coils inserting.The rotor coils are made from cooled pulled flat copper wire, class F insulated. The end bells mounted on both ends are of non-magnetic steel.The rotor is mounted with centrifugal fans or axial flow fans with high tensile aluminum alloy blades.4.4 BearingsThe generator bearings are high pressure oil recycling lubricated, fitted within the cast bearing houses. It has self aligning bearing pads, which is covered with babbitt alloy to avoid the Pb-Sn Alloy at high temperature. Oil outlets are fitted on both sides of bearings for customers selection. The high pressure oil system can be provided according to customers requirements.The lubrication oil for generators shall be provided by turbine supplier using the same oil supply system with turbine.4.5 Cooling systemThe cooling system is designed according to airflow theory together with generator output, with air pressure head provided by fans mounted on the rotor; To ensure the generator cooling efficiency, the stator frame is allocated into several air out blocks along the axial direction and the stator core are divided into air ducts. Further more, special slots for air ventilation are machined on the rotor shaft.The heat generated during the generator operation will emit through stator and rotor coil insulation, go to the air cooler and return to the generator to complete a cooling circulation. The cooler consists of 4 or 5 sections made from tubes of copper H62. The design is made so that the generator can deliver minimum 3/4 or /5 of rated output with one section out service for cleaning purpose, while maintain the temperature rise within the limits and allowing initial cooling air temperature higher than design value; For air circuit supplement, air filters are provided in the cooler sections.4.6 Brushless excitationThe brushless excitation consists of AC main exciter, pilot PMG, rotating rectifier, which rotate with the same shaft center of main generator. The use of PMG greatly improve the stability of the power unit.4.6.1 The main exciter rotor core is made from high quality steel laminations and pressed together tightly by end plates. The armature winding is a two-layer wave winding with three output leads going directly to the rotating rectifier.4.6.2 The rotating rectifier consists of two wheels, with three phase rectifying electrical circuits. The two wheels is used for anode and cathode, both of which are electrical powered, and connected to generator rotor coils.4.6.3 The PMG and AC exciter share the same shaft, same frame and rotor, hanging outside the pedestal bearing at the exciter end.4.7 InstrumentsTo safeguard the operation, the following instruments are furnished:1) 6 RTD PT100 for stator winding and 6 RTD PT100 for stator core;2) One each of air in temperature detector at both ends of stator frame and one on the stator frame;3) One oil temperature detector on the bearing house, and provision for tele temperature monitoring sensor;4) 2 off air out temperature detector at the stator bottom, Cu50 or PT100;Normally, the air in temperature shall no exceed 40 deg centigrade. The allowable temperature rise (class B) for main parts of the generator corresponding to the cooling air is as follows:PartMeasuring methodTemperature rise limitStator windingRTD embedded between the top and bottom coils in the slot80KStator coreRTD embedded80KRotor windingBy resistance90K4.8 Excitation Control SystemEach QFW steam turbine generator is fitted with a computer controlled automatic voltage regulator (AVR). The AVR has the both automatic and manual control, one of them in operation and another standby. It can shift to standby channel and locked fault channel. The regulation method can be either voltage constant, or power factor constant. The excitation is fitted with all kinds of fault alarming and protection functions, of high automation and reliability.5. 4 POLE GENERATORSQFW-4P series generators are developed using the international advanced softwares, design and manufacturing technology of generators. As high-tech products, thye filled the technical blanck of generators in China. The generators performance, such as noise, vibration, reliability, maintenance etc, are all in the leading position in China, which is also in line with international leading technology of generators.5.1 GeneralThe generator is in single layer construction. The cooling system is closed cycling ventilation with coolers mounted on the top. The generator stator, bearing pedestals are all mounted on the base plate made from several pieces, which are to be completed together, leveled, and fixed on the foundation by bolts in power plant. To adjust the mounting dimensions, sliding plates is provided for base plate, and shims for stator, end shields, bearing pedestals.To avoid harmful shaft current, insulation between bearing and ground at non driven end is furnished, and earthing brushes fitted on the turbine end.5.2 Stator designThe generator stator is box constructed.It consists of stator frame, stator core and winding. The frame is made of steel plates, light but strong. Inside the frame, it is divided into many air blocks in axial direction. The end shields at both ends are made from fabricated steel, mounted on the stator frame by bolts. The stator leads come out on frame side plate mounted terminal box. The stator core is made from high quality silicon steel covered on both sides with solid insulation, then sectioned and pressed by dove tail bars around the core, which is further clamped tightly on the supporting bars fixed on the frame. Between every two sections, I shape bars are used to form the radial ventilation paths.The stator coil is in rectangular type, made from fabric glass backed copper, with F class insulation, mica paper tapped and hot pressed. The winding ends are wrapped by fibre rope and braced tightly, totally VPI treated together with core, so that the power unit has a great improved short circuit impact resistance.5.3 Rotor designThe rotor is of laminated cylindrical type;Shaft is made of a solid steel alloy, slotted at radial direction for air ventilation;Rotor lamination is of high tensile steel plate, with slots punched for rotor coils;Rotor core is sectioned in line with stator core to form a ventilation circuit for rotor cooling. Damper coils on rotor can increase the capacity to withstand force due to short circuit and single phase earthing.The rotor coils are made from cooled pulled flat copper wire, class F insulated. The end bells mounted on both ends are of non magnetic steel.The rotor is mounted with centrifugal fans or axial flow fans with high tensile aluminum alloy blades.Rotor including both core and winding is completely VPI treated.5.4 BearingsThe generator bearings are high pressure oil recycling lubricated, fitted within the cast bearing houses. It has self-alignment bearing pads, which is covered with babbitt alloy to avoid the Pb-Sn Alloy at high temperature. Oil outlets are fitted on both sides of bearings for customers selection. The high pressure oil system can be provided according to customers requirements.The lubrication oil for generators shall be provided by turbine supplier using the same oil supply system with turbine.5.5 Cooling systemThe cooling system is designed according to airflow theory together with generator output, with air pressure head provided by fans mounted on the rotor; To ensure the generator cooling efficiency, the stator frame is allocated into several air out blocks along the axial direction and the stator core are divided into air ducts. Furthermore special air slots are machined on the rotor shaft.The heat generated during the generator operation will emit through stator and rotor coil insulation, go to the air cooler and return to the generator, to complete a cooling circulation. 5.6 Brushless excitationThe brushless excitation consists of AC main exciter, pilot PMG, rotating rectifier, which rotate with the same shaft center of main generator. 5.6.1 The main exciter is built with armature, of which rotor core is made from high quality silicon steel laminations. Rotor coil is double layers wave form, secured in the slots by 3240 glass fiber plate, and its coils ends wrapped by the non-oriental glass fibre tape. The armature has three leads which is wrapped by non-oriental glass fibre tape and go though the rotor shaft slots to be connected on the rotating rectification wheel. Pole coils are made from glass fibre taped polyester enamel copper wire, fitted and secured by 2 bolts on the pole core.5.6.2 The rotating rectifier consists of twelve rotating rectification diodes, among which 2 off diodes consists of one bridge to have a three phases bridge type current rectifier. The diodes are concentred on one side of the wheel in order to save the shaft length. The rectified anode and cathode leaded to and connected with generator rotor coils.5.6.3 The PMG and AC exciter share the same shaft, a common frame and rotor, hanging outside the pedestal bearing at the exciter end. The stator core is made from fabricated steel, core from 0.5mm thickness high quality silicon steel, coils from polyester enamel copper wire with six terminals fixed in the terminal box connection board. Rotor is of radial magnetic field, with permanent magnetic made of rubidium-iron-boron fixed on the shaft slots to form 16 off poles. Each group of magnetic steel and pole tips is fixed on the shaft by bolts.5.7 InstrumentsTo safeguard the operation of generators, the following instruments are furnished:1) 6 RTD PT100 for stator winding and 6 RTD PT100 for stator core;2) One each of air in temperature detector at both ends of stator frame and one on the stator frame;3) One oil temperature detector on the bearing house, and provision for tele temperature monitoring sensor;4) 1 off air out temperature detector at middle of the stator, PT100;5) 2 off water leakage detectors at the bottom of water cooler.Normally, the air in temperature shall no exceed 45 deg centigrade. The allowable temperature rise (class B) for main parts of the generator corresponding to the cooling air is as follows:PartMeasuring methodTemperature rise limitStator windingRTD embedded between the top and bottom coils in the slot80KStator coreRTD embedded80KRotor windingBy resistance90K Temperature limit is 35-45 for bearing oil inlet, 65 for oil outlet, 80 for bearing shell.5.8 Advanced technology1) High mechanical protection up to IP54, suitable for hazardous environment with wide adoptability;2) Single layer arrangement with cooler top mounted. This design occupies a small space and easy to install and maintenance. (The traditional China made generator has two layers with cooler underneath mounted, which requires a dedicated cooling cubic between generator and cooler, which increased the difficulties for installation and maintenance.)3) Low noise of 85dB(A), environment protected;4) High efficiency reached through advanced electrical analyze software, improved air circuit and mechanical design, scientifically reduced the generator losses. The generator efficiency is 0.2-0.5% higher than that of the traditional standard designed generators, through which power consumption is reduced which is in line with national energy conservation strategy.5) Low temperature rise. The advanced air circuit design enable the produced heat to go outside easily. It is 10-15 degree lower than the traditional design, which increaseed the motor service life and operation stability.6) Advanced excitation. The excitation consists of PMG, main and pilot exciter, which has remarkable features, such as large design margin, high frequency, quick response, less harmonic effect, high anti-disturbance ability, and