JB/T 6764-1993 Technical requirements for general purpose industrial steam turbines
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T 6764-1993
Technical requirements for general-purpose industrial steam turbines
Published on August 21, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on October 1, 1993
Mechanical Industry Standard of the People's Republic of China
General-purpose industrial steam turbines, technical requirements 1 Subject content and scope of application
JB/T 67641993
This standard specifies the main performance indicators of general-purpose industrial steam turbines and the basic requirements for the main structure and auxiliary equipment. This standard applies to general-purpose industrial steam turbines. Cited standards
GB1348
GB4159
GB7231
GB8117
GB8542
GB9239
GB9439
GBJ236
JB1265
JB1266
JB286 2
JB2901
JB/T6765
ZBK54030
ZBK54038
3 Terminology
3.1 Normal
Steel pressure vessels
Ductile iron castings
Metal low temperature Charpy impact test method
Basic identification colors and symbols for industrial pipelines Thermal performance test procedures for steam turbines in power plants
Technical conditions for turbine gear transmission
Determination of allowable imbalance of brushed rotor balance quality Grey cast iron parts
Design specifications for power installations in explosion and fire hazardous areas Specifications for construction and acceptance of welding projects for field equipment and industrial pipelines Technical conditions for vacuum-treated carbon steel and alloy steel forgings for turbine rotors and main shafts Technical conditions for vacuum-treated alloy steel forgings for turbine rotor discs and impellers Technical conditions for steam turbine packaging
Technical conditions for rust prevention of steam turbines
Technical conditions for special-purpose industrial steam turbines
Technical conditions for flexible couplings of industrial steam turbines Technical conditions for steam turbine steel castings
Indicates parameters under normal operating conditions such as normal power, normal speed and normal steam acquisition parameters. The unit efficiency is highest under normal operating conditions. This operating point is generally the acceptance operation point where the seller guarantees its performance. 3.2 Rated
The maximum power and corresponding speed specified for a 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 tripping device. The setting value of the tripping speed varies with the speed control system. 3.5 Maximum steam inlet parameters
The maximum steam inlet pressure and temperature during continuous operation of the steam turbine. Approved by the Ministry of Machinery Industry on August 21, 1993
Implementation on October 1, 1993
3.6 Minimum steam inlet parameters
JB/T 67641993
The minimum steam inlet pressure and temperature during continuous operation of the steam turbine. 3.7
Maximum exhaust pressure
The maximum exhaust pressure of the steam turbine when it is in continuous operation. 3.8
Minimum exhaust pressure
The minimum exhaust pressure of the steam turbine when it is in continuous operation. 3.9Maximum exhaust cylinder pressure
The maximum exhaust pressure allowed by the buyer for the cylinder under the maximum steam inlet parameters. 3.10Speed variation rate
The total amplitude of the speed variation (or speed fluctuation) that deviates from the speed setting value of the steam turbine under the following stable operating conditions as a percentage of the rated speed is called the speed variation rate of the speed control system. When the steam parameters (inlet pressure, inlet temperature, exhaust pressure) are set at the highest value and remain unchanged a.
When the speed regulator is adjusted to the rated power and the rated speed; b.
When the external control device is not put into use and is fixed in the open position, the steam enters the regulating steam valve without restriction. #=±n+An×100%
Where: — speed change rate;
△ni—speed change above the set speed; An
speed change below the set speed;
△n, rated speed.
The change rate includes the slow rate and the continuous swing rate of the speed. 4 Technical requirements
4.1 General
4.1.1 The steam turbine and its auxiliary equipment shall be designed and manufactured to have a service life of at least 20 years (excluding wearing parts) and uninterrupted continuous operation for 3 years under the specified operating conditions.
4.1.2 The steam turbine shall be able to operate under the condition of deviation of steam pressure and temperature, but the deviation value shall not exceed the following requirements; 4.1.2.1 Steam inlet pressure
During the continuous 12-month operation period, the average value of the steam inlet pressure shall not exceed its maximum pressure value. For normal operating conditions, under the above conditions, the steam inlet pressure shall not exceed 105% of the maximum pressure. For abnormal operating conditions, the inlet steam pressure is allowed to have an occasional swing value not exceeding 120% of the maximum pressure, but not exceeding 12 hours in the cumulative operation period of every 12 months.
4.1.2.2 Inlet steam temperature
In the continuous 12-month operation period, the average value of the inlet steam temperature shall not exceed the maximum temperature. For normal operating conditions, under the above conditions, the inlet steam temperature shall not exceed the maximum temperature by 8°C. For abnormal operating conditions, it may vary within the range of 8 to 14°C exceeding the maximum temperature, and the cumulative time shall not exceed 400 hours in the operation period of every 12 months. It is also allowed to operate at a swing value of less than and equal to 15 minutes within the range of 14 to 28°C exceeding the maximum temperature, but the cumulative time shall not exceed 80 hours in the operation period of every 12 months, and it is never allowed to exceed the maximum temperature of 28°C. Exhaust pressure of back-pressure steam turbine
In the continuous 12-month operation period, the average value of the exhaust pressure shall 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 lower limit deviation value shall be agreed upon by the buyer and the manufacturer. Note: The star "" mark next to the clause number indicates that the part contains content selected by the buyer or agreed upon with the manufacturer. These contents can be indicated in the data sheet (see Appendix A) or stated in the contract. 2
4.1.2.4* Exhaust pressure of condensing steam turbine JB/T6764—1993
The expected deviation value shall be specified by the buyer so that it can be taken into account in the design of the steam turbine. 4.1.3 The steam turbine shall meet the following requirements:
It shall meet the guaranteed steam consumption rate under normal steam parameters, normal power, and positive belt conversion: b, continuous operation at the highest continuous speed and any speed within the specified range; the power at the lowest steam inlet parameters and the highest or lowest exhaust pressure shall be agreed upon by the buyer and the manufacturer. When the rated power is required to be generated at the rated speed, it can be achieved by opening the overload valve or opening the manual steam regulating valve: d Continuous operation at the rated power and rated speed at the highest steam inlet parameters and the highest or lowest exhaust pressure. 4.1.4 All equipment will not be damaged when it is operated at a speed lower than the trip speed setting value and at the safety pressure setting value. 4.1.5 All equipment should be easy to maintain, and the main components such as cylinder assemblies and bearing seats should be able to be accurately positioned during reinstallation. 4.1.6 Control devices, bearing seats, steam seals and oil supply devices should all be considered to reduce the entry of moisture, dust and foreign matter during operation or shutdown.
4.1.7 Single-stage steam turbines should be able to start quickly and reach full load. 4.1.8 All places where water may accumulate in the steam inlet pipe, steam room, cylinder body, steam seal and piping system should be able to be completely drained. When the buyer requires the noise of the unit to be controlled, the sound level and measurement method can be agreed upon by the buyer and the manufacturer. 4.1.9
4.1.10*All electrical components and devices shall be adapted to the buyer’s site category, grade and group requirements as specified in GBJ58. 4.1.11*The buyer shall specify whether the device is indoors (heated or unheated) or outdoors (with or without a shed) and the working climate and environmental conditions (including maximum and minimum temperatures, abnormal humidity or dust, etc.). The unit and its auxiliary equipment shall be adapted to operate under the specified conditions. 4.1.12 The steam turbine shall at least be able to withstand the external forces and torque values calculated and verified in accordance with Appendix A of JB/T6765. 4.2 Main structure
4.2.1 Cylinder
4.2.1.1 It shall be able to operate when the specified steam inlet pressure and temperature simultaneously reach the worst values. 4.2.1.2 Suitable sealing coatings are allowed to be used on the axial center plane of the cylinder, and no gaskets shall be used. When gaskets are used to seal between radial center planes, there shall be a gasket limiting structure to ensure safety and reliability. 4.2. 1.3
Generally, lifting screws, guide posts and positioning pins should be provided to facilitate disassembly and reinstallation. Lifting screws shall not damage the sealing surface. Lifting brackets or eye screws are only used to lift the upper cylinder. The guide posts should be of sufficient length to prevent damage to the rotor when installing the upper cylinder. 4.2.1.4 The threaded hole structure of the cylinder should be used as little as possible. Bolt connection
Preferably use studs, and try to use through connections; leave enough space at the bolt location to facilitate the use of pipe sleeve wrenches or socket wrenches; b.
Do not use round nuts with holes, slotted nuts or screws. 4.2.1.6 Cylinder accessories
Nozzle groups, plates or stationary blades should be replaceable structures. 4.2.1.7 Pipeline interface of cylinder
4.2.1.7.1 Pipes on cylinders should be connected by flanges as far as possible. Where flange connection is not applicable, pipes and cylinder bodies can be connected by threads or welded in socket holes. Pipes with threaded holes or socket holes should be installed as follows. The pipe length should not exceed 150mm. It should be inserted into the hole or welded firmly. a.
Pipes should be equipped with butt welding flanges or flat welding flanges b.
Threaded joints should be sealed welded. However, there are exceptions for joints, instrument joints or places where disassembly is required for maintenance on cast iron cylinders. c.
4.2.1.7.2 Screw holes that are not connected to pipes should be plugged with steel screw plugs. 4.2.1.7.3 The nominal diameter of non-instrument connection channels, pipes, pipe fittings, flanges, etc. should not be less than 15mm. 4.2.1.7.4#
The flanges selected should comply with the provisions of domestic standards. The supply of flange accessories shall be agreed upon by the buyer and the manufacturer. Non-standard flanges shall comply with the following requirements,
JB/T 6764—1993
Steel flanges and cast iron flanges with a nominal pressure less than 4MPa may adopt a flat sealing surface structure: a.
The flange on the integral component shall ensure that the coaxiality of the center circle of the bolt hole relative to the inner hole of the flange can ensure that the positioning gasket does not extend into the fluid; b.
Flanges with thicker thickness and larger outer diameter than standard flanges are allowed; c.
The manufacturer shall provide all matching parts; d.
The connecting flanges for auxiliary pipelines provided by the manufacturer can be made according to the manufacturer's standards. 4.2.1.7.5 The interfaces connected with fixed studs on the cylinder shall be equipped with studs and nuts. 4.2.1.8 The nozzle chamber of a single-valve steam turbine and the first stage of a multi-stage steam turbine shall be equipped with an interface for connecting a pressure gauge. 4.2.2 Rotor
4.2.2.1 The rotor shall ensure that the instantaneous speed is up to 110% of the trip speed setting value and is safe. 4.2.2.2 The structure of the impeller set shall ensure that there is no relative movement between the impeller and the main shaft under any specified starting or operating conditions and any speed equal to or less than 110% of the trip speed.
4.2.2.3 The main shaft shall be precision machined, and the surface roughness parameter Ra value of the coupling, shaft neck and carbon ring sealing area shall be 0.8μm. 4.2.2.4 If a non-contact vibration or axial displacement meter is used, the surface of the vibration probe monitoring area on the rotor shall be coaxial with the shaft neck. The entire monitoring area (including radial vibration and axial displacement) shall not have printed marks and scratches or other discontinuous surfaces such as oil holes or keyways. It shall not be sprayed or electroplated with metal or added with a sleeve. The surface roughness parameter Ra value is 0.4 or 0.8um. It is best to use grinding, polishing or rolling processes. This area should be strictly demagnetized or other methods should be used to make the combined value of mechanical and electrical runout not exceed 25% of the maximum allowable peak-to-peak amplitude or the values of the following two cases, whichever is greater: 6μm for radial vibration monitoring area;
13μm for axial displacement monitoring area.
4.2.2.5 The shaft section at the carbon ring seal should be protected by corrosion-resistant and wear-resistant materials. The coating material used by the manufacturer and the final key layer thickness should be stated.
The rotor of the driving generator should be able to withstand the torque when the generator is short-circuited. 4. 2. 2. 6
4.2.2.7 Moving blades
4.2.2.7.1 The composite stress of the blade (static stress plus alternating stress) should be low enough to ensure safe operation even if a co-reporting state occurs within the operating range.
All moving blades should be adapted to operate within the specified speed range and in transient state. 4. 2. 2. 7. 2
4.2.3 Steam seal
4.2.3.1 The external steam seal should adopt replaceable labyrinth seal or carbon ring seal or a combination of the two. 4.2.3.2 If carbon ring seal is used, the friction speed of the shaft seal surface should not exceed 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 0.24MPa. The spring of the carbon ring seal should be made of stainless spring steel. When determining the cold state of the sealing ring, the change of the steam working temperature should be considered. 4.2.3.3 The steam seal of the intermediate plate shall be a replaceable labyrinth seal. 4.2.3.4 The steam seal working below the maximum steam pressure shall be introduced with positive pressure sealing steam to prevent air infiltration. When the steam seals at both ends are connected, connecting pipes and pipe accessories shall be provided. The pipes shall have a common joint leading to the buyer's sealing steam supply pipe. In normal operation, the sealing steam should preferably be drawn from the positive pressure section of the steam turbine.
When specified, a separate steam seal extraction device shall be provided, which is connected to the steam seal to reduce the possibility of leakage to the outside and contamination of the bearing oil 4.2.3.5*
.
4.2.3.6 The cutting pipes and components of the steam seal and steam seal extraction system shall generally be sized according to three times the leakage of the steam seal design interval. 4.2.4 Rotor dynamic characteristics
4.2.4.1 Critical speed
4.2.4.1.1 Amplification factor of rotor vibration
Where: nc—rotor critical speed;
JB/T6764—1993
n1—speed below the critical speed, with an amplitude of 0.707 times the peak amplitude at the critical speed; n2—speed above the critical speed, with an amplitude of 0.707 times the peak amplitude at the critical speed; When the vibration probe measures the rotor amplification factor to be greater than or equal to 2.5, the frequency at the peak amplitude is called the critical frequency, and the corresponding shaft speed is called the critical speed. Systems with amplification factors less than 2.5 are considered to have extremely damped systems. 4.2.4.1.2 The critical speed should be determined by the damped rotor unbalance response analysis method, and 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 Within the specified operating speed range or avoidance margin range, the support system supplied by the manufacturer shall not produce resonance unless the resonance can be attenuated to the maximum extent. 4.2.4.1.4 The operating speed range of the unit and any starting retention speed will not cause resonance due to the critical speed of the shaft system and the unit. All speeds that are not expected to stay between zero and the tripping speed should be stated in the product manual. 4.2.4.1.5 The critical speed of the first order rigid vibration mode of a single-stage steam turbine shall be at least 120% of the maximum continuous speed. 4.2.4.2 Lateral vibration analysis
4.2.4.2.1 The actual critical speed of a steam turbine with the same structural dimensions and the same rotor and bearing structure that has been manufactured in the past is allowed to be used as the critical speed value of the corresponding steam turbine and can be included in the quotation. For newly designed steam turbines with new rotors or new bearing structures, the manufacturer shall conduct lateral vibration analysis. The analysis requirements shall be in accordance with JB/T6765. When specified, the manufacturer shall provide calculated and tested avoidance margin values or only provide either value. They shall meet the requirements of 4.2.4.1.5 and JB/T6765 respectively. 4.2.4.3 Torsional vibration analysis shall meet the requirements of JB/T6765. 4.2.4.4 Vibration and balance 4.2.4.4.1 The main components of the rotor, such as the impeller and the balance disc, shall be statically balanced separately or dynamically balanced at low speed. 4.2.4.4.2 The dynamic balance quality of the rotor shall be G2.5 in GB9239. The coupling shall be balanced separately. When the rotor with a half coupling is dynamically balanced, it is not allowed to remove weight from the coupling. 4. 2. 4. 4. 3
4.2.4.4.4 The balanced rotor is subjected to a mechanical running test. The relative dynamic unfiltered amplitude peak-to-peak value measured on any plane on the shaft adjacent to the radial bearing within the maximum continuous speed or the specified operating speed range shall not exceed the value calculated according to the following formula: A=25.4X,
Wherein, A—unfiltered amplitude peak-to-peak value, μm; nn—maximum continuous speed, r/min.
When A is greater than 50μm, the limit value of A is taken as 50μm. At any speed higher than the maximum continuous speed or less than or equal to the tripping speed, the amplitude shall not exceed 150% of the maximum value recorded at the maximum continuous speed. 4.2.4.4.5*When specified, the runout values of the electrical and mechanical quantities at the vibration measuring part shall be measured and recorded. The method is to use the probe of the non-contact measuring instrument and the micrometer to measure the runout value in the same cross section when the rotor rotates in the V-groove shim or bearing. The total momentum of the electrical and mechanical quantities should not be greater than 25% of the A value or 6μm, whichever is greater. 4.2.4.4.6 When the amplitude value of the shaft cannot be measured, the vibration can be measured on the bearing seat. The unfiltered vibration intensity at the speed specified in 4.2.4.4.4 shall not exceed 3.8mm/s.
4.2.5 Bearings and bearing seats
4.2.5.1 The radial bearing shall adopt dynamic pressure sliding bearings or rolling bearings. The rolling bearing shall meet the design life of not less than 25000h under the maximum axial and radial loads and rated speed.
4.2.5.2 The horizontal steam turbine shall be equipped with a thrust bearing, which shall be able to withstand axial thrust in both directions. Multi-stage steam turbines shall use hydrodynamic sliding thrust bearings. When rolling bearings are used, they shall have the same design life as radial rolling bearings. 4.2.5.3* Vertical steam turbines may use ball or roller type radial thrust bearings lubricated with oil or grease. The thrust bearings shall be calculated based on twice the thrust (upward or downward) of the driven equipment. When using grease for lubrication, excess grease shall be prevented. 5
JB/T6764-1993
4.2.5.4 Hydrodynamic radial bearings shall have a center face for easy assembly. The bearings shall be able to suppress the instability of the hydrodynamics and provide sufficient resistance to limit the rotor perturbation to the limit amplitude value when running at the critical speed (see 4.2.4.4.4). 4.2.5.5 Hydrodynamic thrust bearings
4.2.5.5.1 Multi-wall type with steel lining and Babbitt alloy cast on both sides, usually designed to have the same thrust capacity in both axial directions, and continuous pressure oil lubrication is configured on both sides. Www.bzxZ.net
Thrust bearings should generally be placed at the steam inlet end of the turbine and be able to adjust the axial position of the rotor and the gap between the thrust plate and the pad. 4.2.5.5.2 The size of the thrust bearing should be determined based on the continuous operation of the turbine under the most unfavorable working conditions. 4.2.5.5.3 The thrust plate should preferably be integral with the shaft. Additional margin should be left on each thrust surface of the integral plate for reprocessing when the thrust plate is damaged. The replaceable thrust plate should be securely fixed on the main shaft to prevent micro-vibration 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 shall not exceed 7.5um within the thrust plate radius value of every 100mm. 4.2.5.5.4 For gear couplings, the additional axial thrust should be calculated as follows: F = (0.25 × 9550)
Where: F coupling axial thrust, kN,
nr-rated speed, r/mint
D-coupling pitch diameter, mm,
P.--rated power, kW.
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4.2.5.5.5 The thrust load of diaphragm couplings should be calculated based on the maximum allowable deflection angle allowed by the coupling manufacturer. 4.2.5.5.6 If the thrust bearing bears the thrust of multiple rotors, it should be designed according to the maximum thrust after superposition. .·(5)
4.2.5.5.7 The maximum load borne by the thrust bearing under the specified speed, lubricant and lubricant temperature conditions should not exceed 50% of the bearing limit load under these conditions.
Note: The extreme root load refers to the load under the minimum oil film thickness allowed without failure in continuous operation, or the load that does not exceed the creep or service strength in the highest temperature area of the babbitt alloy on the pad, whichever is smaller. 4.2.5.6 Bearing seat
4.2.5.6.1 The bearing seat should have a center dividing surface to facilitate the replacement of bearings without removing the unit cylinder. 4.2.5.6.2 Where the main shaft passes through the bearing seat housing, a labyrinth end seal and oil deflector should be installed; packing seals are not used. Seals and oil deflectors should be made of materials that will not produce sparks. The structure of seals and oil deflectors should effectively retain oil in the housing and prevent foreign matter from entering the housing.
4.2.5.6.3 The bearing seat structure of hydrodynamic bearings lubricated with pressurized oil should reduce oil foam to a minimum. The oil return system should ensure that the oil and oil foam level is lower than the bottom of any rotating body in the housing and the shaft end seal. Under the most unfavorable operating conditions, the oil temperature rise through the bearing and bearing seat should not exceed 28°C, and the bearing oil outlet temperature should generally not exceed 75°C. 4.2.5.6.4* If specified, each bearing seat should have a structure that can accommodate two radial displacement probes and an axial displacement probe and a speed sensor mounted on the thrust bearing end.
4.2.5.6.5 The bearing seat of the pressureless oil lubricated bearing should have an oil filling and oil drain hole greater than or equal to 10mm. A fixed oil level indicator should be provided.
4.2.5.6.6 The bearing seat of the bearing lubricated with oil rings should be equipped with an observation window to monitor the oil rings during operation. 4.2.5.6.7 Cooling measures should be provided for oil ring lubrication or splash lubrication. Under the specified operating conditions, ensure that the oil temperature in the bearing seat does not exceed 82°C. If cooling is performed by a cooling water jacket, there shall be no water leakage in the oil storage area. When a cooling coil structure is used, the coil shall be made of anti-corrosion materials. There shall be no pressure-bearing connectors inside the oil storage area. The wall thickness of the coil shall not be less than 1mm and the pipe diameter shall not be less than 13mm. 4.2.6 Lubrication
4.2.6.1 Pressure lubrication or pressureless lubrication shall meet the requirements of 4.2.5. The pressure oil lubrication system must also comply with the provisions of 4.3.5.
4.2.6.2 If a common oil supply system is used to supply oil to two or more units (such as compressors, gear transmissions and turbines), the characteristics of the oil shall be jointly agreed upon by the general package party and the sellers of each equipment using the oil supply system. Turbine oil is usually used in the common oil system. 6
JB/T6764-1993
4.2.6.3*If the unit is required to have a wide speed range, fast start or low speed operation, these state values should be specified, and special consideration should be given to the lubrication of the turbine and gear transmission. 4.2.6.4*When using a pressure oil system (excluding the governor with its own oil system), the oil system should include the following items:, the main oil pump driven by the main shaft (except for the oil supply from an external oil source), it should be considered that the oil pump will not be damaged when the unit is automatically started due to lack of oil in the oil suction pipeline during shutdown;
lubrication during starting can be supplied by oil rings or manual auxiliary oil pumps; use an independent shell and tube type oil cooler as much as possible, and do not use a built-in oil cooler; c
a full-flow oil filter with a sawn pressure shell, and no pressure relief or automatic bypass. The oil filtration accuracy is 25um. .
Thermometers (with sockets for inserting manual sleeves) should be installed before and after the oil cooler and the oil return of the bearing: pressure gauges (with valves for removable pressure gauges) should be installed before and after each pressure block and oil filter; when specified, an oil flow peep sight should be installed on the oil return pipeline of each bearing seat; when specified, a standby oil pump with independent drive and automatic control can be equipped; the oil tank should have the following characteristics:
The capacity should be large enough and should not be less than the oil supply capacity of the main oil pump at normal speed for 2 minutes; there should be facilities to separate air and prevent impurities from entering the oil pump suction port; the oil filling port, oil level indicator and exhauster should be able to adapt to outdoor installation, with inclined bottoms and interfaces to drain the oil; there should be suitable cleaning manholes.
4.2.6.5When specified, a removable steam heater or a thermostatically controlled immersion electric heater installed outside the oil tank should be provided to heat the stored oil before starting in cold weather. The heat capacity of the heater should enable the oil in the oil tank to be heated from the specified lowest ambient temperature to the required starting temperature within 12 hours. The maximum power per unit area of the immersion electric heater is 2.3W/cm. When using an oil pan or oil ring for lubrication, the immersion depth of the oil pan or oil ring is 3 to 6mm, and the oil pan should be securely fixed on the shaft 4.2.6.62
4.3 Auxiliary equipment
4.3.1 Gear transmission device
4.3.1.1 Gear transmission devices are used in situations where they can improve the efficiency of the steam turbine. 4.3.1.2 Steam turbines with a rated power greater than 56kW shall generally not use an integral rotor structure integrated with a gear transmission device. 4.3.1.3 The gear transmission device shall comply with the requirements of GB8542. 4.3.2 Couplings and coupling guards.
4.3.2.1 Coupling
4. 3. 2. 1. 1
Unless otherwise specified, the flexible coupling and guard between the driving and driven units shall be provided by the manufacturer of the driven unit. When specified, the driving half-coupling shall be installed by the turbine manufacturer. If the turbine manufacturer provides its adjacent equipment (such as gear transmission), the guard of the flexible coupling between these equipment must be supplied. 4.3.2.1.2 The coupling shall comply with the provisions of ZBK54030. The type and installation arrangement shall be agreed upon by the buyer and the two manufacturers of the driving and driven equipment. Unless otherwise specified, a separate coupling with a spacing of at least 125 mm shall be used. 4.3.2.1.3 The turbine manufacturer shall provide the coupling supplier with the geometric dimensions that match the coupling, the axial displacement caused by thermal effects and other factors, and the required shaft end spacing. 4.3.2.1.4 The external gear sleeve and the main shaft are interference fit, and the transmission power value at the joint shall be at least equal to the rated power value of the coupling. 4.3.2.2 Coupling guard
The coupling guard shall be easy to disassemble and cover all the exposed parts of the coupling. 4.3.3 Chassis
If a chassis is used, the scope of the equipment to be mounted on it shall be clearly defined. 4.3.3.2 The foot of the equipment and the mounting surface of the chassis shall be machined. 7
JB/T6764—1993
Vertical jacking bolts shall be provided between the foot of the equipment and the chassis. 4.3.3.31
The chassis mounted on concrete shall also be provided with leveling screws or washers. 4.3.3.4
The connection parts and leveling components between the turbine components and the chassis shall be supplied by the chassis vendor. 4.3.3.5
The chassis shall have a lifting structure, and when lifted together with all the equipment on it, the chassis shall not be permanently deformed and will not damage the components installed on it. 4.3.3.6
|The mounting blocks of the chassis shall be on the same plane so that a foundation at a same elevation can be used for continuous grouting. 4.3.3.7
When specified, the rigidity of the chassis shall be suitable for installation without secondary grouting. 4.3.4 Control system and measuring device
4.3.4.1 General
4.3.4.1.1
The measuring device and its installation position shall comply with the requirements of the purchase contract. 4.3.4.1.2 Control system and measuring device suitable for the site shall be provided. 4.3.4.1.3*When specified, manually controlled steam valves capable of economical operation under abnormal parameters shall be provided. The purchaser shall specify the number of manually controlled valves required and the performance data to be provided.
4.3.4.2 Control system
4.3.4.2.1 A corrosion-resistant steam filter screen shall be provided in front of the main steam valve. The effective flow area of the filter screen shall be at least twice the cross-sectional area of the steam inlet pipe of the steam turbine and shall be easily replaceable without dismantling the steam inlet pipe. Unless otherwise specified, a hydraulic relay speed control system shall be provided. The performance values of the speed control system shall be agreed upon by the buyer and the seller, and the range is as follows:
The inequality rate is 0.5%~10% of the rated speed; a.
The speed variation rate is ±0.25%~±0.75% of the rated speed; b.
The tripping speed is equal to 110%~115% of the maximum continuous speed; c.
When the rated load is instantly dropped, the adjustment system shall be able to control the speed of the unit without causing the emergency trip device to operate. d.
4.3.4.2.3 Unless otherwise specified, the speed shall be adjustable by a manual speed regulator. 4.3.4.2.4* If a control signal for controlling the speed is specified, the manufacturer shall provide a speed adjustment mechanism that meets the following requirements: The full control signal range specified by the buyer shall correspond to the operating range required by the driven equipment. Unless otherwise specified, the maximum a.
control signal shall correspond to the highest continuous speed: the action or interruption of the control signal, or the failure of the speed regulating mechanism shall not prevent the governor from limiting the speed to the maximum permissible b.
value, nor prevent manual adjustment with the manual speed regulator. 4.3.4.2.5* The speed adjustment range of the governor and the manual speed regulator shall meet the requirements of the buyer. 4.3.4.2.6 The main steam valve and regulating valve shall generally use metal rings or other non-compression type bushings for valve stem sealing. If the inlet steam pressure is equal to or higher than 1.7MPa (g), a steam exhaust point shall be set in the middle of the sealing structure. 4.3.4.2.7 The steam turbine shall be equipped with a separate overspeed emergency trip system to shut off the steam entering the turbine when the operating speed reaches the tripping speed. The emergency trip system shall have the following characteristics:
Easy to access;
b. Manual tripping can be performed at the highest steam inlet pressure and maximum steam inlet flow in the pipeline; The steam turbine can trigger the trip valve to shut down the steam turbine under any load state; c.
It can be reset when the pipeline reaches the highest steam inlet pressure. d.
4.3.4.2.8*For steam turbines with exhaust pressure lower than atmospheric pressure, the need to operate the exhaust vacuum breaker by the trip system shall be agreed upon by the buyer and the manufacturer.
Note: For steam turbines with exhaust pressure lower than atmospheric pressure, even if the emergency trip valve is closed, there may be steam leakage that makes it impossible to shut down the steam turbine and its driven equipment. The vacuum breaker introduces air into the exhaust cylinder, which increases the exhaust pressure and reduces the exhaust time. For steam turbines that exhaust to a common condenser system, a highly reliable emergency trip or multiple trips are required. Instrument panels and dashboards
4.3. 4.3. 1 *
Instrument panels
JB/T6764-1993
When specified, local instrument panels should be supplied. The buyer should specify the scope of required instruments. 4.3.4.3.2 Instrument panels
4.3.4.3.2.1*When specified, instrument panels that meet the buyer's requirements should be provided. The buyer may specify that only the instrument panel is installed on the same foundation of the unit or installed separately. The operator at the control point should be able to clearly see all the instruments on the instrument panel. 4.3.4.3.2.2 When the control or measuring instrument requires multiple wiring points, a wiring box and wiring should be provided. Wires shall be enclosed in metal conduits and boxes. Identification labels shall be attached to all wires and terminals. 4.3.4.4 Instruments and Accessories
4.3. 4. 4.1*
Tachometer
When specified, tachometers shall be supplied. The purchaser may specify the type of tachometer, such as electrical or reed type. Unless otherwise specified, the tachometer range shall be at least 0 to 125% of the maximum continuous speed. 4.3.4.4.2 Thermometer sleeves
Thermometers and thermometers installed in pressure lines or filled fluid lines shall be equipped with stainless steel removable stem thermometer sleeves. 4.3.4.4.3 Pressure gauges
The range of the pressure gauge is generally selected to be twice the normal pressure value, and the maximum value shall not be less than 110% of the setting value of the safety valve used. The operating element of the pressure gauge shall be nickel-chromium stainless steel. 4.3.4.5 Alarm and shutdown
4.3.4.5.1*
The manufacturer shall provide and install switches and operating devices in accordance with the regulations. Exhaust pressure over-alarm device
4.3.4.5.2*
When the exhaust pressure over-alarm device is required, for condensing steam turbines, the set pressure is 35kPa (g), and the set pressure value of back-pressure steam turbines is either 10% higher than the maximum exhaust pressure, or 70kPa higher, whichever is greater. 4.3.4.5.3 Alarm switch and disconnect switch 4.3.4.5.3.1 Each alarm switch and disconnect switch shall have a separate housing and be located in a place that is convenient for maintenance. An airtight single-gate double-throw switch shall be used, and mercury switches shall not be used.
4.3.4.5.3.2 Unless otherwise specified, electrical switches for open circuit (de-energized) alarm and closed circuit (energized) interruption shall be provided. 4.3.4.5.3.3 The setting value of the alarm and interruption switches cannot be adjusted outside the housing. 4.3.4.5.4 Housing of arc type switch
Special attention should be paid to whether the performance of the arc type switch housing meets the explosion-proof requirements of the buyer. The manufacturer shall provide and install the switch control device and the indicating device in accordance with the buyer's regulations. The buyer may negotiate with the manufacturer and select from the following contents in 4.3.4.5.5 *
.
Vibration is too large
Axial displacement of rotor is too large
Speed is too high
Bearing temperature is too high
Lubricating oil supply pressure is too low
Lubricating oil supply temperature is too high
Oil level in oil tank
Oil filter pressure difference
Exhaust pressure is too high
Exhaust pressure is too low
Vibration and displacement detector
4. 3. 4. 6.1*
Corresponding monitor.
4.3.4.6.2 *
4.3.4.6.3+
JB/T 67641993
The Purchaser shall specify in the Contract Data Sheet whether non-contact probes, velocity or acceleration sensors and their equivalents are required. Vibration and axial displacement sensors and monitors shall be supplied when specified. Velocity and acceleration sensors and monitors shall be supplied when specified. 4.3.5 Piping and accessories
4.3.5.1 General
4.3.5.1.1 The piping system shall include piping, isolation valves, regulating valves, safety valves, thermometers and thermowells, pressure gauges, pressure reducing valves, throttling devices, peep sights and related exhaust and drain valves. 4.3.5.1.2 The piping system is an auxiliary system attached to the steam turbine and auxiliary equipment, which includes the following items: lubricating oil piping system; control oil piping system; steam piping, steam seal piping system: cooling water piping system; drainage or drainage piping system; condensate piping system; air or nitrogen piping system.
4.3.5.1.3 The manufacturer shall provide the relevant piping system in accordance with the contract. 4.3.5.1.4 The piping design shall be carried out in accordance with the contract, and the following items shall be achieved: have appropriate support and protection to prevent damage caused by movement or transportation, operation and maintenance;
have appropriate flexibility and easy access for operation, maintenance and cleaning; b.
The layout of the piping system shall be reasonable;
eliminate air pockets;
without removing the pipe, it can be completely drained from the lowest point. e.
4.3.5.1.5 Pipes should be made by bending and welding. Minimize the use of flanges and pipe connectors. Threaded joints should be used as little as possible. Pipe-over-tube welding should not be used.
4:3.5.1.6 Welding is not allowed where instruments are connected to cast iron equipment or where disassembly is required for maintenance. 4.3.5.2 Oil pipelines
4.3.5.2.1 When the return oil flow rate is 0.3m/s, the oil flow should not exceed half of the diameter and should be configured to drain the oil smoothly (consider the influence of foam generation). The pipeline flowing to the oil tank should have a continuous downward slope of at least 2%. As far as possible, the branch pipeline should be arranged along the flow direction of the main pipe and merge into the main pipe at 45°.
2 Welded lining rings or sleeve simple connectors should not be used. The pressure pipe downstream of the oil filter shall be free of obstructions that may accumulate dirt. 4.3.5.2.2
Sleeve welded fittings shall not be used. If specified, stainless steel fittings shall be provided. 4.3.6 Special tools
4.3.6.1 Tools and installation tools for assembling, disassembling or maintaining the turbine equipment that are not purchased from outside shall be provided as part of the turbine package. 4.3.6.2 The tools provided shall be packed in sturdy boxes marked with the tool number and machine number. Each tool shall be labeled to indicate its purpose.
4.3.7 Insulation and covers
4.3.7.1* If specified, insulation and covers that are easy to install and remove shall be provided when the operating temperature of the turbine casing is greater than 70°C. 4.3.7.2 Under normal conditions, the insulation layer should ensure that the surface temperature of the shell is less than 70°C, and the shell and insulation layer should ensure that they are not easily damaged during disassembly or assembly.
4.4 Materials
44.1 General
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