JB/T 6765-1993 Technical conditions for special purpose industrial steam turbines
Some standard content:
Machinery Industry Standards of the People's Republic of China
Technical Conditions for Special Purpose Industrial Steam Turbines
1 Subject Content and Scope of Application
JB/T 6765—93
This standard specifies special purposes The main performance indicators of industrial steam turbines and the basic requirements for the body structure and auxiliary equipment. This standard applies to special purpose industrial steam turbines. 2 Reference standards
GB150
GB1348
GB4159
GB8117
GB7231
GB8542
GB9439
GBJ58
GBJ236
JB1265
JB1266
JB2862
JB2901
JB/Z92
Steel pressure vessel|| tt||Nodular iron castings
Metal low-temperature Charpy impact test method
Power station steam turbine thermal performance test procedures
Basic identification colors and identification symbols for industrial pipelines Technical conditions for turbine gear transmission
Gray iron castings
Specifications for the design of electrical installations in explosion and fire hazard locations. Specifications for construction and acceptance of field equipment and industrial pipeline welding projects. Technical conditions for vacuum-treated carbon steel and alloy steel forgings for steam turbine rotors and main shafts. Steam turbines Technical conditions for vacuum treatment of alloy steel forgings for rotor disks and impellers Technical conditions for steam turbine packaging
Technical conditions for rust prevention of steam turbines
Mildproofing of tropical electrical products and materials
ZBK54036 industrial steam turbine Technical conditions for lubrication and regulating oil systems ZBK54030 Technical conditions for industrial steam turbine flexible couplings ZBK54038 Technical conditions for steam turbine steel castings 3 Terms
3.1 Normal
Indicates parameters under common working conditions such as normal power , normal speed and normal steam parameters, the unit has the highest efficiency under wide operating conditions. This operating point is generally the acceptance operating point for the seller to guarantee its performance. 3.2 Rated
The maximum power and corresponding speed specified by the steam turbine are called rated power and rated speed, which include the margin required by the driven equipment. 3.3 Maximum continuous speed
It is at least 105% of the maximum operating speed required by the driven machinery under any specified operating conditions. 3.4 Tripping speed
refers to the operating speed of the emergency disconnector. The setting value is generally about 110% of the maximum continuous speed. 3.5 Maximum steam inlet parameters
The highest steam inlet pressure and temperature during continuous operation of the steam turbine. 3.6 Minimum steam input parameters
Approved by the Ministry of Machinery and Broadcasting Industry on 1993-08-21
Implemented on 1993-10-01
68
JB/T 676593||tt| |The minimum inlet steam pressure and temperature during continuous operation of the steam turbine. 3.7 Maximum exhaust steam pressure
The highest exhaust steam pressure during continuous operation of the steam turbine. 3.8 Minimum exhaust steam pressure bZxz.net
The lowest exhaust steam pressure during continuous operation of the steam turbine, 3.9 Maximum exhaust steam pressure of the exhaust cylinder
The highest exhaust steam pressure allowed by the cylinder required by the buyer under the highest steam inlet parameters. 3.10 Speed ??change rate
When the steam turbine meets the following stable operating conditions, the speed change that deviates from the speed setting value (or the total amplitude of the speed fluctuation as a percentage of the rated speed is called the speed change of the speed control system rate. When the steam parameters (inlet steam pressure, inlet steam temperature, exhaust steam pressure) are set at the highest value and remain unchanged: a
When the output power of the relay regulator is adjusted to the rated power and reaches the rated speed: b.
When the external control device is not put into use and is fixed in the open position, the Yan steam can enter the regulating steam pot without restriction c.
=±n+m×100%|| tt | ,——Rated rotation.
The speed change rate includes the retardation rate and the continuous swing rate of the speed. 4 Technical requirements
4.1 General
.+....||tt| |....(1)
4.1 The steam turbine and its auxiliary equipment shall have a service life of at least 20 years (excluding easy-to-photograph parts) and operate continuously for three years under specified operating conditions. Years of design and belt production.
4.1.2 The steam turbine should be able to operate under certain deviations in steam pressure and temperature, but the deviation value shall not exceed the following requirements: 4.1.2.1 Inlet steam pressure
During the continuous 12-month operation period, the average value of the inlet steam pressure shall not exceed its maximum pressure value. For normal operating conditions, the inlet steam pressure shall not exceed 105% of the maximum pressure for abnormal operating conditions. , the accidental swing value of the inlet steam pressure is not allowed to exceed 120% of the maximum pressure, but it does not exceed 12h during the cumulative operation period of every 12 months.
4.1.2.2 Inlet steam temperature
During the 12-month operation period, the average inlet steam temperature shall not exceed the maximum temperature. For normal operating conditions, the inlet steam temperature shall not exceed the maximum temperature by 8°C. For abnormal operating conditions, it may exceed the maximum temperature. Within the range of 8 to 14°C, the cumulative time shall not exceed 400h during each 12-month operation period. It is also allowed to operate at a swing value of less than and equal to 15min within the range of the maximum temperature of 14 to 28°C, but every 12 months. The cumulative time during the monthly operation period shall not exceed 80 hours, and the maximum temperature shall never be exceeded 28°C. 4.1.2.3* The exhaust steam pressure of the back-pressure turbine shall be the average exhaust steam pressure during the continuous 12-month operation period. Do not exceed the maximum exhaust pressure. Under the above conditions, the exhaust pressure should not be higher than 110% of the maximum exhaust pressure. The minimum deviation value is determined by the buyer and the manufacturer. Note: Those marked with "" next to the article number. , indicating that this part contains content selected by the buyer or agreed with the manufacturer. These content can be noted in the data sheet (see Yanglu B) or stated in the contract. The exhaust pressure of the condensing steam turbine
4.1.2.4*3
64
JB/T6765-93
The expected deviation value is specified by the buyer to be considered in the turbine design. , 4.1.3 The steam turbine shall meet the following requirements:
a. The guaranteed steam consumption rate should be met under normal steam parameters, normal power and normal speed, b. Continuous operation at the highest continuous speed and any speed within the specified range, c.* Under the highest steam intake parameters and high volume or the lowest exhaust Continuous operation at rated power and rated speed when the steam pressure is high, or continuous operation under the conditions specified in the contract,
d, *The power at the lowest steam inlet parameters and the highest stripping pressure causes the maximum rotational speed and the corresponding The minimum speed requirements are agreed between the buyer and manufacturer.
Operates continuously under specified conditions of extraction or admission, or both extraction and admission. e.
f. It is possible to conduct a trial operation without coupling under the condition of high inlet steam parameters (when the regulation is unstable, measures such as inlet steam throttling and pressure reduction are allowed), and the operation time shall comply with the provisions in the instruction manual.
4.1.4 All equipment can operate without damage to the running surface when it is lower than the tripping speed setting and safety pressure setting value. 4.1.5 The combined performance of the steam turbine and driven equipment shall be jointly borne by the buyer and the manufacturer. If specified, the manufacturer shall review the buyer's piping and foundation drawings, and may also send representatives to inspect the unit alignment and piping. . 4.1.6 All equipment should be easy to maintain. The main components of the machine, such as cylinder components and bearing seats, should be able to be accurately positioned during reassembly. 4.1.7 Control devices, bearing seats, steam seals and oil supply devices should all be considered to reduce the entry of mixed steam, dust and foreign impurities during operation or shutdown.
4.3.8 Steam inlet pipe, steam exhaust pipe All places where water may accumulate in the chamber, red body, steam seal and piping system should be fully drained. When the buyer requires noise control of the unit, the sound level level and measurement method shall be agreed between the buyer and the manufacturer. 4.1.9
4.1.10* All electrical components and devices shall comply with the buyer’s location category, level and group requirements specified in GBJ58. 4.1.11 The steam turbine can at least withstand the external force and external moment values ??that meet the verification calculation in Appendix A. 4.1.12 The buyer should specify whether the steam turbine device is installed indoors (heated or not) or outdoors (with or without coupling) and the working climate and environmental conditions (including the highest and lowest temperatures, unusual temperatures or dust, etc.), The unit and auxiliary equipment should be adapted to operate under specified conditions. 4.2 Body structure
4.2.1 Cylinder
4.2.1.1 It should be able to operate when the pressure and temperature under the specified steam inlet parameters reach the worst values ??at the same time. 4.2.1.2 The maximum allowable working pressure of the cylinder should be at least equal to the setting value of the safety valve used. For condensing steam turbines, the allowable limit pressure of the exhaust cylinder should be complete vacuum and at least 0.07MPa(g). Note: Usually, a full-flow safety lubrication is required in the steam pipe between the exhaust steam outlet and the exhaust valve to avoid steam overpressure and possible failure. 4.2.1.3 Only suitable sealing coatings are allowed to be used on the cylinder and radial center. No plastic materials are allowed. 4.2.1.4 Pre-lifting screws, guide posts and positioning pins should be provided to facilitate disassembly and reassembly. Pre-lifting operations should be carried out. Nails must not damage the sealed painting. The lifting hook or lifting ring is only used to lift the upper half of the cylinder. The guide post should be of sufficient length to prevent damage to the rotor when installing the lifting cylinder. 4.2.1.5 End bolt connection
Priority is given to double-ended studs, and through-connection forms are used as much as possible: a.
There is enough space where the blasting bolt is located to facilitate the use of pipe sleeves or sleeves. Hand; b.
e. Do not use round nuts with holes, fine channels or spiral ladder climbing nails. 4.2.1.6 The cylinder screw hole structure should be used as little as possible. 4.2.1.7 Cylinder accessories
The nozzle group, partition or vane holding ring should adopt a replaceable structure. 4.2.1.8 Cylinder pipe interface
4.2.1.8.! The pipe connection of the cylinder should be flanged as much as possible. Where flange connection is not applicable, pipes with a diameter less than 40mm are allowed to be threaded with the cylinder body. The pipe pipes with threaded holes should be installed as follows: a. The length of the pipe should generally not exceed 150mm. ,. and controlled into the hole; 65
b. There should be butt welding flange or flat welding flange on the pipe: c. Threaded joints should be sealed and welded.
JB/T6765--93
4.2.1.8.2 Screw holes without pipes should be plugged with steel screw plugs. 4.2.1.8.3 The nominal diameter of non-instrument connection channels, pipes, pipe fittings, flanges, etc. shall not be less than 15 mm. 4.2.1.8.4* The selection of flanges should comply with domestic standards. The supply of flange accessories is determined by the buyer and manufacturer. Non-standard flanges should comply with the following requirements.
Steel with a nominal pressure less than 4MPa The steel flange and the iron flange can adopt a flat sealing surface structure; 8.
The flange on the entire component should be such that the center of the blasting bolt hole is fixed to the inner hole of the flange, and the coaxiality ensures that the positioning washer does not stretch. into the fluid: b.
allows the use of flanges that are thicker and have a larger outer diameter than the standard flange; C,
The manufacturer should provide all matching parts; d.||tt ||e.
The connecting flange provided by the manufacturer can be connected to the manufacturer's standard production. 4.2.1.8.5 The interface on the cylinder connected by fixed studs should be equipped with studs and nuts. 4.2.2 Rotor
4.2.2.1 The rotor should be guaranteed to be safe at an instantaneous speed up to 110% of the tripping speed setting value. 4.2.2.2 The set impeller structure should ensure that there is no relative movement between the impeller and the main shaft at any speed equal to or less than 110% of the decoupling speed. 4.2.2.3 Each rotor should have a clear identification number, preferably marked on the coupling. End letters so that they can be easily seen when the rotor is disassembled. 4.2.2.4 The spindle should be precision machined, and the surface roughness parameter Ra value when installing the impeller, coupling, journal and carbon ring sealing position is 0.8μm.
4.2.2.5 is used for radial vibration measurement The surface of the monitoring area should be coaxial with the journal. The entire sensor monitoring area of ??the spindle should not have printed marks, holes or other discontinuous surfaces such as oil holes or keyways. The surface should not be spray-painted or plated with metal or metal. After adding the shaft, the surface roughness parameter Ra value is 0.4 or 0.8 μm. For good measurement, use processes such as polishing, full polishing or rolling. This area should be strictly demagnetized or other methods should be used to ensure that the combined mechanical and electrical runout does not exceed the following value
For the radial vibration probe monitoring area, it is 25% of the maximum allowable amplitude peak or 6m, whichever is chosen The larger one; b. The monitoring area of ??the axial displacement operating head is 13um. 4.2.2.6 The shaft section at the carbon ring seal should be protected with corrosion-resistant and wear-resistant materials. The widely used method for manufacturing this layer, the coating material and the final coating thickness should be stated.
4.2.2.7 The rotor of the driving generator should be able to withstand the torque of the generator during short circuit. 4.2.2.8 Moving blades
4.2.2.8.1 The tangential in-phase, tangential out-of-phase, axial interrogation, and torsion of the blades caused by the rotational speed within 15 times and the puff frequency and double the nozzle rate As well as any other high-order response data type of excitation, there should be a resonance line diagram (Campbell diagram or equivalent diagram) to verify that it is outside the specified operating speed range, otherwise the dynamic stress level of the moving blade should be limited, and the energy storage period Even if resonance occurs within the transmission range, it can still operate safely. This should be verified by using the composite fatigue strength diagram (Goldman diagram or equivalent). The moving blades should be able to operate at the common alarm frequency when the engine is warmed up. 4.2.2.8.2 All moving blades should operate within the specified speed range and in instantaneous transition states. Unless otherwise specified, it is generally assumed that the torque is proportional to the square of the speed.
4.2.3 Steam seal
4.2.3.1 The external steam seal should adopt a replaceable uterine seal, and generally no carbon ring seal is used. 4.2.3.2 When carbon ring seal is used, the friction speed of the shaft seal surface should not be greater than 50m/s. The number of carbon rings depends on the use conditions and the requirements for leakage. The maximum average pressure difference of each sealing ring is 0.17MPa. The carbon ring seal spring should be made of stainless spring steel. When determining the cold state trace of the sealing ring, the change in steam working fluidity should be considered. 4.2.3. The steam seal of the 3rd stage partition plate should adopt a replaceable quick palace seal. 4.2.3.4 The steam seal operating below atmospheric pressure should introduce positive pressure sealing steam to prevent the entry of air. When the steam seals at both ends are connected, connecting pipes and pipeline accessories should be supplied. The pipes should have public joints leading to the buyer's seal. Steam supply pipe, during normal operation, the sealing steam should preferably come from the positive pressure section of the steam turbine.
56
JB/T 676593
4.2.3.5* When specified, a separate steam seal extraction device should be supplied, which is connected to the steam seal to reduce external leakage and the possibility of contaminating the dissipation oil.
4.2.3.6 All pipes and components of the steam seal and steam seal extraction system should generally be sized according to three times the designed leakage of the steam seal. 4.2.4 Rotor dynamic characteristics
4.2.4.1 Critical speed
4.2.4.1.1 Amplification system effect of rotor vibration
F=
where:. ---Critical speed of the rotor;
n
n,-n;
n---lower than the critical speed, and the amplitude is 0.707 times the peak amplitude of the vibration at the critical speed. Speed ??n. - is higher than the critical speed, and the vibration slack is the speed at 0.707 times the amplitude peak at the critical speed; (2)
When the dynamic test actually measures the amplification factor of the rotor to be greater than or equal to 2.5, the operating aid will be reduced The frequency at is called the critical rate, and the corresponding shaft speed is called the critical transfer. A system with an amplification factor lower than 2.5 is considered a system with extremely high damping. 4.2.4.1.2 The critical speed should be determined by the damped rotor unbalance response analysis method. When the critical speed is lower than the maximum continuous speed, it should be determined by testing on the test bench.
4.2.4.1.3 The support system supplied by the manufacturer within the specified operating speed range or avoidance range shall not produce resonance unless the resonance can be attenuated to the maximum extent.
4.2.4.1.4 The operation specifications of the unit and any starting dwell speed dock will not cause resonance due to the critical speed of the shaft system and the unit. The transfer of all undesirable stops from fog to tripping speed shall be stated in the product instructions for use. 4.2.4.2 Transverse vibration analysis
4.2.4.2.1 In order to ensure that the machine vibration amplitude is within the allowable range at any speed from waiting to tripping speed, the manufacturer should make the rotor unbalanced Response analysis.
4.2.4.2.2 The damped unbalanced response analysis should at least consider the following factors: a. The cost, quality and elucidation characteristics of the support (base, machine channel and bearing seat) taking into account the influence of rotational speed changes; b. The changing values ??of bearing lubricating oil film melting and damping, which are related to rotational escape, shear load, preload, oil Temperature, the accumulated assembly error of the bearing is related to the maximum to minimum interval:
s, speed, including each starting dwell speed, travel speed related to the load range, tripping rotation and speed slip state; c. Rotor mass, including the mass moment of half the coupling, the influence of stiffness and damping (such as fit, stiffness and damping of the fluid, and the influence of the frame and cylinder):
e asymmetric load (such as Partial steam intake, gear force, steam stream and eccentric clearance). When there are regulations, lateral motion analysis of the shaft system should be carried out 4.2. 4.2.3 *
4.2.4.2.4. The pre-analysis room for damped unbalance should include at least the following items: a. The gripping curve of each response speed from the tripping speed to the tripping speed and the judgment of the shooting type, as well as the drop that occurs above the tripping speed. Mode shape curve diagram and mode shape determination (including extremely damped and undamped conditions). b. For a specific mode shape, the unbalance amount is configured according to the following requirements. When passing through each critical speed zone, the frequency, phase and response amplitude at the alarm probe position are obtained. The unbalanced plate should be enough to increase the displacement of the rotor on the probe to the amplitude limit value, and the amplitude limit value is determined according to equation (3). 12000
L,=25.4
where: L - amplitude limit value (unfiltered silver spoke peak value), m; n----the operating speed closest to the critical state, r /min: (3)
The imbalance should be greater than twice the specified remaining imbalance limit. Unbalanced counterweights, determined by analysis to have the greatest adverse impact on a specific vibration mode, should be placed at one or more locations between the bearing spans (for example, in the middle of the span for translational vibrations, or in the middle of the span for tilting vibration vibrations). Close to both ends and out of phase by 180*). For the curved shape with the largest deflection at the shaft end, the unbalance should be concentrated at the shaft extension end: each response vibration intensity diagram in item cb should represent the joint surface of the coupling, the center of the bearing, the position of the alarm probe and each sealing section The long axis vibration 67
JB/T6765-93
and phase. It should also show the smallest designed diameter flow space at the seal: According to the provisions of item b, the test imbalance amount configuration area diagram used in the factory qualification test. The test weight should be 2 to 8% of the allowable remaining imbalance. The placement location is determined by the manufacturer, e, *If specified, the degree of response of the rotor without nylon shall be included. The stiffness diagram can be derived from the damped unbalanced analysis of term C. It represents the relationship between frequency and support system stiffness superimposed on the calculated support system stiffness curve. 4.2.4.2.5 Damped unbalance response analysis should show that the machine meets the following acceptance criteria under the unbalanced conditions specified in 4.2.4.2.4 b:
If the amplification factor F<2.5, it can be considered The response under large damping does not require an avoidance margin; a.
b, if F=2.5~3.55, an avoidance margin of 15% higher than the maximum continuous speed and 5% lower than the lowest operating speed is required. Opening degree: c
If F>3.55 and the critical response peak speed is below the minimum operating speed, the required avoidance margin B (which is the percentage of the minimum operating speed) is calculated according to equation (4): ||tt| |B100 (84+ F-)3% .
(4)
d. If F>3.55 and the critical response peak speed is higher than the tripping speed, the required avoidance degree B (is the highest continuous The percentage of rotation speed) is calculated according to Wu (5):
B[(126-P-3
6
+(5)
-1001%||tt ||4.2.4.2.6 The calculated peak-to-peak value of the unbalanced operating amplitude of the rotor at any speed from zero to tripping (see item b in 4.2.4.2.4) shall not exceed the designed small diameter clearance of the complete machine. 75% of the value (floating ring seal damage), if the design in 4.2.4.2.7 cannot meet the avoidance margin requirements or there is still a critical speed that falls within the operating speed range, the rotor insensitivity test should be carried out to determine the total Agree on the acceptance vibration value, but first it should meet the requirements of 4.2.4.2.6. Factory supervision of 4.2.4.3 unbalance response analysis and 4.2.4.3.1 will comply with the rotor unbalance amount and configuration of item d in 4.2.4.2.4. The actual critical speed response measured on the test bench at the location determined by the manufacturer (usually on the coupling) is a criterion for the validity of the damped unbalance response analysis. Note that due to the pressure, measurement and pressure requirements of the test bench and the field , load, support conditions, etc. are not in phase, the test results may be inconsistent with the expected values ??on site. 4.2.4.3.2 The measurement parameters during the test are the rotation speed and shaft amplitude and their corresponding phases. The maximum amplitude of the damage should be calculated (i.e. Long axis amplitude), which is the correlation sum of the vibration and phase of each pair of X-Y vibration probes. The long axis amplitude of each response value should not exceed the limit specified in 4.2.4.2.6 of the recording instrument. The measuring range should have enough stickiness so that the maximum value measured during deceleration of the test unit is within 60% to 100% of the measuring range. See 4.2.4.3.4 for the estimated maximum peak value. Note: Alarm during identification. The weight value should be subtracted from the total runout loss including electrical and mechanical components under mirror rotation (300~600z/min). Generally, the dynamic loss with the bearing seat should also be subtracted
4.2.4.3. .3 If the data obtained from the above test or the damping unbalanced response analysis (based on the unbalanced condition of item b in 4.2.4.2.4) does not meet one of the following conditions, structural correction and corrected response analysis should be carried out. And conduct supplementary tests. 8. A certain critical response does not meet the requirements of avoidance margin (see 4.2.4.2.5) or falls within the operating speed range; b. The long-axis amplitude of a certain response peak does not meet 4.2.4.2.6. limits specified in . 4.2.4.3.4 Acceptance criteria for factory qualification testing: 8. At any rotation speed, the deflection of the main shaft should not exceed 90% of the minimum design flow gap: b. Within the operating speed range, the spindle leverage should not exceed 55% of the minimum design flow gap, or 150% of the allowable vibration limit at the probe (see 4.2.4.2.4 item b). The above provisions The spindle lift value is based on the reported ratio calculated from the relevant parts indicated in item c of 4.2.4.2.4, and is calculated by multiplying these ratios by the long axis amplitude measured in 4.2.4.3.2. The acceptance is based on the calculated deflection, not the inspection of the steam seal after the test. The test shall be deemed to be unsatisfactory if the test results in the occurrence of whiskers in any area. Slight scratches on the internal steam seal, if the gap does not exceed the regulations, will not be regarded as damage,
4.2.4.4 Torsional alarm analysis
68
JB/T 6765-93
4.2.4.4.1 The torsional common frequency of the entire unit shaft system should be at least 10% higher or lower than any possible excitation frequency within the specified operating speed range.
4.2.4.4.2 It should be avoided that the critical speed of torsion is two times or higher multiples of the operating speed, or even if there is an unfavorable excitation frequency, it should be shown that it is harmless. In addition to frequencies that are multiples of the operating speed, if there are torsional excitation forces or non-synchronous excitation forces that are not functionally related to the operating speed, they should be considered in the rotation analysis. 4.2.4.4.3 If the calculated torsional joint value falls within the limits specified above and the filter element cannot be improved, a stress analysis should be performed to prove that the shaft system is harmless under the action of resonance force.
4.2.4.4.4* If specified, the manufacturer should conduct a torsional vibration analysis of the entire connected shaft system and propose improvements needed to meet the requirements of 4.2.4.4.1~4.2.4.4.3. 4.2.4.5 Vibration and balance
4.2.4.5.1 The main components of the rotor such as impeller, balance plate, etc. should be separately statically balanced and additionally low-speed dynamically balanced. 4.2.4.5.2 After the rotor is dynamically balanced, the maximum remaining unbalance disk on each shaft side is required to be 1Uam6350W/ng
Wuzhong: U--residual unbalance, g·mm; W---journal dead weight Load, kg:
na Maximum continuous speed, r/min
(6)
4.2.4.5.3 When high-speed balancing (balance at operating speed) is specified, The vibration degree of the balancing machine support should not be greater than 1.8mm/s. 4.2.4.5.4 The coupling should generally be dynamically balanced independently. When the rotor with a half coupling is dynamically balanced, it is not allowed to remove weight from the coupling. 4.2.4.5.5 The balanced rotor is subjected to a mechanical operation test. Within the maximum continuous speed or the specified operating speed range, the amplitude of the relative vibration without filtering is measured on any plane adjacent to the radial bearing. Should exceed the calculated value according to formula (7): A=25.4X,
In the formula, A——peak amplitude without filtering, pm:n.---load continuous speed,/min.
/12000
pe
(7)
When A is greater than 50, the limit of A is 50um. At any speed less than or equal to the tripping speed from the maximum continuous speed plane, the amplitude shall not exceed 150% of the maximum value recorded at the highest continuous speed. Note: The limit value of A is not to be confused with the limit value of Lv. 4.2.4.5.6 The runout values ??of the electrical and mechanical quantities at the vibration measurement site should be measured and recorded by using a non-contact measuring instrument probe and a dryer while the rotor is rotating in the V-groove pad or bearing. The total runout of the sub-meter when filtering the dynamic value, electric power and machine quantity in the same diagram section should not be greater than 25% of the A value or 6μm, whichever is the larger value. 4.2.4.5.7. When the amplitude of the shaft cannot be measured, the maximum vibration can be measured on the bearing seat. The unfiltered vibration intensity is not greater than 3.8mm/s4.2.5 Bearing and bearing seat
4.2.5.1 Radial bearing|| tt|| should be a dynamic pressure radial bearing. The bearing should have a horizontal center plane, which can suppress the instability of the hydrodynamic force, and provide sufficient resistance to limit the rotor vibration from reaching the limit amplitude when operating under any specified working conditions, including critical speed (see 4.2.4.5. 5). The thrust transmission bearing | thrust capacity, both equipped with continuous pressure oil lubrication. 4.2.5.2.2 The size of the thrust bearing should be determined based on the continuous operation of the turbine under the most unfavorable working conditions. 4.2.5.2.3 The thrust plate should preferably be integral with the shaft. The integral plate should be Additional margin is provided for remachining if the thrust plate is damaged. The replaceable thrust plate should be reliably fixed on the spindle to prevent micro-wear on the shaft. The surface roughness parameter Ra value of the two thrust surfaces of the thrust plate is 0.4μm, and the axial total runout value of the two thrust surfaces is no more than 7.5um per 100mm of thrust plate radius. 4.2.5.2.4 For gear couplings, the additional axial thrust should be calculated according to formula (8) 69
JB/T 6765-93
F=(0.25X0550)xP.||tt ||n,
P.--Rated power, kW.
4.2.5.2.5 The thrust load of the diaphragm coupling should be calculated based on the maximum deflection angle allowed by the coupling manufacturer. 4.2.5.2.6 Assuming that the thrust bearing bears the thrust of multiple rotors, it should be designed according to the maximum thrust after superposition. 8 |
Note, the plate limit negative pressure refers to the load under the small thickness of the debris allowed for the lowering of the continuation line of the east construction, or the highest mixing area of ??babbitt alloy on the tile does not exceed its frequency. It becomes the recommendation to take into account the service strength, and the minimum value is recommended. 4.2.5.2.8 The thrust bearing should generally be placed at the steam turbine inlet end, and can adjust the axial position of the rotor and the gap between the thrust plate and the pads. 4.2.5.3 Bearing seat
4.2.5.3.1 The bearing seat should have a horizontal center plane so that the bearing can be easily replaced without dismantling the unit cylinder. 4.2.5.3.2 Where the main shaft passes through the bright body of the bearing seat Labyrinth chrysanthemum seals and oil retaining rings should be installed, and packing seals should not be used. The seal and oil retaining ring should be made of materials that will not produce sparks. The structure of the seal and the limit should be effectively maintained in the shell and prevent external substances from entering the body.
The dynamic pressure lubricated with pressure oil The bearing housing structure should be cut to a minimum to reduce fluid concentration. The oil return system should ensure that the oil and oil foam level 4.2.5.3.3
is lower than the bottom of any rotating body in the housing and the shaft end seal. Under the most unfavorable operating conditions, the temperature rise through the bearing and bearing seat should not exceed 28°C, and the daily oil temperature of the bearing should generally not exceed 75°C. 4.2.5.3.4 The bearing diameter should be narrow enough to accommodate a radial vibration probe and an auxiliary displacement tracer and speed sensor at the end of the thrust bearing. When installing a shaft pressure transmitter There should also be corresponding lead-out line structures, 4.2.6 Lubricating oil and control oil systems.
4.2.6.1*
Supplier:
a
b.
c.
d.
according to Ordering requirements, when the steam turbine manufacturer supplies the pressure oil system, it should clearly specify the bearings that are driven and driven (including gear devices) for one or more of the following purposes: continuously lubricated couplings; ||tt| |Control system;
Sealing oil system (only considered if it supplies oil integrally with the lubrication system). 4.2.6.2 When the lubrication and control oil system is supplied by others, the turbine manufacturer shall:,
Provide stable and instantaneous oil volume and pressure ballast, oil filtration accuracy and benzene to be subject to the maximum heat load, oil viscosity, cooling The oil mixer behind the oiler provides the pressure of each gear to lubricate the pipeline to the main oil supply wiper port and the oil return pipe that returns all the oil to the oil tank. b
If a common oil supply system is used to supply oil to two or more units (such as compressors, gear transmission installations and steam turbines), the 4.2. 6.3 *
characteristics of the oil should be determined by the general oil supply system. The complete set party shall agree with each seller of the equipment using the oil supply system. Turbine oil is commonly used in utility oil systems. 4.2.6.4 Where oil is used to provide grease, there should be appropriate channels to add grease. 4.2.6.5 All oil systems and components should comply with the requirements of ZBK54036. 4.3 Auxiliary equipment
4.3.1 Gear transmission device should comply with the requirements of GB8542, 4.3.2 Coupling and coupling protection or
4.3.2.1* Unless otherwise specified, the driving and driven parts The optional couplings and guards between the engine units should be provided by the manufacturer of the driven unit. If the turbine seller provides its adjacent equipment (such as gear transmission), the flexible couplings and guards between these equipment must be supplied. 4.3.2.2 The coupling shall comply with the requirements of ZBK54030, and the integral type and installation label shall be agreed by the buyer and the two manufacturers of the driving and driven equipment. Unless otherwise specified, a flexible coupling that enables the turbine to operate independently after the steam turbine and driven unit are combined should be used. 70
JB/T6765-93
4.3.2.3 The steam turbine manufacturer should provide the coupling supplier with the geometric dimensions that match the coupling and the axial displacement caused by thermal effects and other factors. and the required shaft end distance. 4.3.2.4 The external gear sleeve and the main shaft have an interference fit, and the transmission power value at their joint should be at least equal to the rated power value of the coupling. 4.3.2.5 The coupling seller shall provide an idle adapter that meets the requirements of 5.3.3.1.8 based on actual needs. 4.3.3 Chassis (the base frame is regarded as a separate small chassis) 4.3.3.1 Vertical pre-lifting bolts should be provided between the feet of the equipment and the chassis. The chassis installed on concrete should also be provided with flat screws or pads. 4.3.3.2 The connections between the turbine components and the chassis and components for leveling shall be supplied by the chassis seller. .4.3.3.3 For units that use a common chassis, the scope of the equipment they can carry must be specified in the order contract. The chassis should have a lifting structure. When lifted together with all the equipment on it, the chassis should have no permanent deformation and no damage to the parts installed on it.
The mounting pads of the chassis should be on each surface so that a foundation with an elevation can be used for continuous grouting. The use of additional bottom plates (calibration 4.3.3.5
flat plates) should be mutually agreed upon by the buyer and the seller. . If necessary, the attached base plate should be supplied by the capable seller. 4.3.4 Control system and measuring device
4.3.4.1 General
4.3.4.1.1 The measuring device and its installation location shall comply with the requirements of the order contract, 4.3.4.1.2* The buyer shall specify Depending on the type of driven machinery and its operating characteristics, the turbine manufacturer should provide a control system suitable for the application.
4.3.4.2 Control system
4.3.4.2.1 When using electric adjustment, at least dual speed signal sensing systems should be provided. When a speed sensing system fails, an alarm should be issued. Keeps the speed signal constant and prevents governor control from malfunctioning. 4.3.4.2.2* Unless otherwise specified, the governor shall control the steam turbine within the specified speed range. Other control methods (such as extraction or admission steam units) should be mutually agreed between the buyer and the manufacturer. 4.3.4.2.3 When the rated load is used up instantaneously, the speed control system should be able to control the speed of the unit so as not to cause the emergency breaker to operate. 4.3.4.2.4 The speed control system should be equipped with a test device to artificially control the maximum set speed of the overspeed governor during the overspeed trip test.
4.3.4.2.5 The turbine speed should change linearly with the external control signal. Unless otherwise specified, the increase in the control signal should increase the turbine speed. 4.3.4.2.6 All control signals specified by the buyer The range should correspond to the remote travel range required by the driven equipment, and the maximum control signal should correspond to the maximum speed or maximum flow.
4.3.4.2.7 The external control signal is activated or the signal is neutral, or the actuator failure shall not hinder the automatic speed limiting function of the speed regulator, nor shall it hinder manual adjustment by the manual speed regulator. Transfer. 4.3.4.2.8 For driving non-generator units, the speed control system shall meet the following requirements: Sales. *The droop should meet the buyer's requirements; b. The speed change rate is less than or equal to ±0.25%; c, *The adjustable speed range should meet the buyer's requirements; when the speed control system is controlled by a signal from an external control device, an actuator that receives the signal from the external control device should be set on the speed regulator: d.|| tt||e.
is equipped with on-site speed regulator.
4.3.4.2.9 For units that drive generators, the speed control system should meet the following requirements: The droop should generally be 3%~5%:
a.
b .The speed change rate is less than or equal to 0.25%; c. Equipped with a remote control speed adjustment device;
, equipped with on-site synchronizer.
4.3.4.2.10 Unless otherwise specified, on a steam turbine with a single regulating valve, there shall be at least two manual valves. Each valve shall have a description of its purpose. These valves shall meet the requirements when the turbine is at the lowest steam intake at the same time. The parameter section has specific requirements for the maximum exhaust pressure, and makes the unit operate at a temperature lower than the rated load of 71
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.