Product Details
BRIEF DESCRIPTIONS
Bypass high Pressure Reducing System is the pressure reducing desuperheater system for turbine bypass applications, also called turbine bypass PRDS. It is one of the most critical systems in the power plant, allowing operation of the boiler independent of the turbine and also providing steam at the same pressure and temperature as the turbine steam expansion process. With this capability, the Bypass high Pressure Reducing System is used in start-up and rapid ramp down modes, protecting the turbine, boiler and condenser from damaging thermal and pressure excursions.
BASIC PARAMETERS |
FEATURES |
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Available inlet pressure: P1<17.0 MPa
Available inlet temperature: T1<570 DegreeC
Available Inlet flow rate: 10%~100%
Outlet pressure controlling accuracy:
P2<0.98 MPa, accuracy range: ±0.04MPa
0.98 MPa<P2<3.82 MPa, accuracy range: ±0.06MPa
P2>3.82 MPa, accuracy range: ±0.15MPa
Outlet temperature controlling accuracy: ±4 DegreeC
Noise Level: <85 dbA
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Apply with forged pressure reducing valve of angle structure, designed specifically to handle severe thermal shock conditions normally associated with turbine bypass applications.
Multi-stage piston trim design gives rapid start-up and shut off capacity, the piston is guided in two areas, with long guiding surfaces and not subject to distortion.
High performance and quick operation pneumatic actuator or Electro-hydraulic actuator is selected, which gives quick action in 5 seconds or even less time for PRDS moving into operation
The multi nozzles provide excellent atomization over a wide range of spray flows. The design optimizes the cooling liquid particle size so that quick evaporation can take place.
The high performance feed water control valve is assembled and gives accurate water supplying to the spray nozzles for desuperheating.
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RECOMMENDATIONS |
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Minimum distance of Temperature Sensor from the point of water injection should be 10 to 12 mtrs
It is recommended to install a strainer of 0.8 mm mesh before water control valve
Spray water should be very clean (equivalent to boiler feedwater)
Instrument quality air is required
Inlet isolation valve is needed
Floor support to safety valve is needed
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DESIGN PRINCIPLE
Layout |
 |
Assemble Parts |
Basic Parameters |
Available inlet pressure: P1<17.0 MPa
Available inlet temperature: T1<570 DegreeC
Available Inlet flow rate: 10%~100% |
Desuperheater System |
Noise Level: <85 dbA |
Classical Venturi design |
Double Venturi Design |
Pressure Class |
Custom-design,
acc to specifications |
Multiple Nozzle with Venturi Design |
Annular Nozzle with Venturi Design |
Size |
From DN200 to DN700 (8" to 28") |
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Additional sizes on request |
Feed Water Control System |
Design Temperature |
Maximal. 570 Degree C
Higher temperature on request |
Feed Water Control Valve |
Strainer and Globe Valve |
Actuator |
Pneumatic |
Check Valve |
Other actuators on request |
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Electric |
Safety System |
Installation |
Horizontal |
Safety Valve |
Connection |
Flange (ASME B16.5) |
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Butt weld (Acc to request) |
Instruments System |
Valves |
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Pressure Gauge |
SA 105 |
Thermometer |
SA182-F11 |
Pressure Transmitter |
SA182-F91 |
Thermocouple |
Additional Materials on request |
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Pipes |
SA-106B |
Others Parts |
SA-355 P11 |
Connection Pipe |
SA-355 P22 |
Counter Flange and Fastens |
SA-355 P91 |
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Additional Materials on request |
Applications |
Apply Standards |
Bypass high Pressure Reducing System is applicable for turbine bypass applications, allowing operation of the boiler independent of the turbine and also providing steam at the same pressure and temperature as the turbine steam expansion process. |
NB/T47033-2013
<Pressure Reducing Desuperheater System>
Manufacturing acc. to ASME
IBR, CE certificated on request |
PRESSURE REDUCING & DESUPERHEATING PART
Basic Control |
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Main Parts |
 |
NY963Y
HP Steam Pressure Reducing Valve
Availability of the pressure reducing valve in the turbine bypass application for steam supply to the process is critical. Reliability and performance are paramount to the operation of the plant. The LY963/663Y PRV design with its unique features stands alone in the industry for steam conditioning applications.
(Details please find control valve brochure) |
Desuperheating Design
The desuperheaters reduce steam temperatures by introducing cooling water directly into the hot steam. Temperature reduction is essentially a matter of heat transfer, where the cooling water is placed in direct contact with steam and receives the necessary heat for evaporation. |
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Venturi Concept
The venturi design is based on a sophisticated concept. The upstream steam comes from venturi chamber with accelerated velocity, which turns the spray water and flows with it through the mixing module where steam and water meld together with very high contacting efficiency. The design brings many advantages including minimal pressure drop, shorter installation length and higher range ability, also there is no moving parts which ensure the stability and low maintenance cost in future operation. |
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Multiple-Nozzle Design
HZVALVE has incorporated the latest technology in the multiple spray nozzle design. The high quality spring loaded nozzle was employed and assembled with desuperheaters to atomize the water droplets and produce the heat transfer contact area necessary for cooling the steam so that to bring steam and water to meld together with very high contacting efficiency. |
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Special Spray Effect
The spray water enters the nozzle chamber through multiple tangentially drilled holes, thereby causing water to swirl within the nozzle chamber. The spring, which is pre-compressed to a certain set pressure, keeps the nozzle plug pressed against the seat. As soon as the pressure differential between the water & steam exceeds the set pressure, the plug lifts from its seat and the spray water exits through the small circumferential opening, in the form of a fine mist. Number of nozzles, spring range and spring set pressure is selected based on the process specifications. |
Feed Water Control Valve
Feed water control valve is one of the most important control components of the feed water line, it controls the supply of feed water to the nozzles, the commonsense is the high performance of feed water control valve with accurate flow and pressure controlling is the priority concern for the operation of desuperheater. |
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High Performance Multiple Cage Control Valve
The multiple-cage guided single seat control valve is used for high pressure and high temperature working condition of steam and water purpose. It is assembled with pressure sealed forged body and trim of anti-cavitation design, processed with high grade alloy steel, which offers the effective solution to high pressure drop conditions. The cooperation between cage and trim ensures the more accurate adjusting performance and very tight sealing under extreme steam conditions.
(Details please find control valve brochure)
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Layout |
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SIZE AND DIMENSION
DRAWING |
No |
Item Name |
 |
1 |
Steam Condition Valve |
2 |
Multipe Nozzle |
3 |
Check Valve |
4 |
Steam Pipe |
5 |
Pressure Gauge |
6 |
Bimetal Thermometer |
7 |
Globe Valve |
8 |
Throttle Valve |
9 |
Control Valve |
No |
CODE |
PRESSURE REUDCE VALVE |
STEAM PIPE OUTLET |
WATER CONTROL VALVE |
SAFETY VALVE |
1 |
PWYK01 |
DN50 |
DN50 |
DN80 |
DN20 |
2 |
PWYK01 |
DN80 |
DN65 |
DN100 |
DN25 |
3 |
PWYK01 |
DN100 |
DN80 |
DN150 |
DN32 |
4 |
PWYK01 |
DN125 |
DN100 |
DN200 |
DN40 |
5 |
PWYK01 |
DN150 |
DN150 |
DN250 |
DN50 |
6 |
PWYK01 |
DN175 |
DN200 |
DN300 |
DN65 |
7 |
PWYK01 |
DN225 |
DN250 |
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DN80 |
8 |
PWYK01 |
DN250 |
DN300 |
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DN100 |
9 |
PWYK01 |
|
DN350 |
|
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10 |
PWYK01 |
|
DN400 |
|
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11 |
PWYK01 |
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DN500 |
|
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12 |
PWYK01 |
|
DN600 |
|
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13 |
PWYK01 |
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DN700 |
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14 |
PWYK01 |
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DN800 |
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http://www.desuperheating.com/
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