Abstract: The hydraulic drive unit of Fast hydraulic control valve and electrical control part of the series design .
Keywords：Fast off valve；Hydraulic actuator；Series Design
1 Overview
Extraction Steam Turbine Cogeneration can be achieved and widely used in thermal power plant of heating systems to prevent backflow of steam turbine extraction steam piping and condensate back flow , turbine speed caused the accident , the steam turbine extraction steam pipes and electric cut-off valve Check valve be installed between the valve off quickly to instantly cut off the steam pipe to protect the security . As soon shut off butterfly valves for fast (<1s), the output power large (> 100kN), must use the hydraulic drive unit , to adapt to various types of valves , quick closing valve on the hydraulic drive device of the serial design .
2 Structure
Hydraulic drive fast off valve by the hydraulic pump station , control valve , accumulator , fast tank, electric control box, 5 parts (Figure 1 ), which can slow the completion of valve opening , slow pass, fast valving , Activities and other activities.
Figure 1 hydraulic drive unit of Fast butterfly shape (1.Electric control box 2.accumulator 3.Hydraulic Pump Station 4.Control valve 5.fast tank)
2.1 Hydraulic Control section
According to the requirements of quick closing valve and calculation of hydraulic driving system of the basic parameters such as " Table 1 . "
| Parameter | Series 1 | Series 2 |
|---|---|---|
| Tank volume V / L | 50 | 80 |
| Rated flow qm / L * min | 2.0 | 3.0 |
| Working pressure p / MPa | 13~16 | 15~18 |
| Packing properties | 4h drop no more than 2MPa | |
| Valve open time | 10 ~ 30s (0 ~ 90 °) adjustable | |
| Time off valve | 10 ~ 30s (90 ~ 0 °) Adjustable | |
| Quick opening valve time | <0.5s ( including the buffer time is less than 1s) | |
| Filter Precision | 10μm | |
| Pre- pressure accumulator py / MPa | 8.0±10% | 9.0±10% |
| Working medium | N46 ~ N68 No. antiwear hydraulic oil | |
Hydraulic Pump Station consists of motor, coupling, hydraulic pump , into the oil filter , pressure filters, fuel tanks and other components, its main role is to pressure oil supply system required for the accumulator to provide flow and pressure , design Using imported low-noise high-pressure gear pumps, pump installation and use of inverted vertical structure of high pressure filters , compact , and ensures the system clean oil to ensure that all control valves to operate correctly. To meet the needs of different fast off valve is divided into two series to be designed .
Figure 2, hydraulic control valve (1 . solenoid valve DT3 2. solenoid valve DT2 3. valve AV1 4. valve AV3 5. valve AV2 6. relief valve RV 7. manometry joint MP 8. valve AV4 9 . Pressure switch KP2 10. Pressure Switch KP1 11. solenoid valve DT1)
Control valve (Figure 2) mainly by the valve block, relief valve , check valve, throttle valves, solenoid valves, pressure switch and pressure gauges etc. , relief valve RV ‘s role is to set system security Pressure valve AV1 is the role of oil back to tank pressure release system , the role of the throttle AV3 off valve to regulate the system speed , throttle valve AV2 is the role of the Valve -conditioning systems , the role of pressure switch is set KP2 Upper limit of hydraulic control system , pressure is the role of relay KP1 Pressure Control limit set point is the role of pressure gauge oil pressure display system , in order to reduce leakage within the system and pump start-up times , saving energy, ease of maintenance And installation, use the import threaded cartridge valves and high-quality two -pass Valve . In order to meet the needs of different fast off valve , the valve block into the left valve block , the middle valve block and valve block of the three parts of the right to design, through different combinations of response to different requirements.
Accumulator valve slowly to open , slow pass, fast , and activities related actions to provide energy storage device through a rigorous specification of the choice of calculation , different for each system to meet the fast butterfly valve system, packing and related Requirements . Used for storage of nitrogen can be seen as an ideal gas , while the rapid expansion and compression process can be regarded as adiabatic change of state , choose the required total volume of the accumulator is calculated as:
Where:
V0- The total volume of an ideal energy storage , m3
ΔV – Accumulator fuel required for the effective row , m3
P0- Accumulator charge pressure ( absolute pressure ), Pa
P1- System minimum working pressure ( absolute pressure ), Pa
P2- System maximum working pressure ( absolute pressure ), Pa
K – polytropic exponent of gas ( nitrogen, volatile index K = 1.4)
Figure 3 Fast tanks
Quick cylinder ( Figure 3) is to promote the butterfly valve by rack and pinion actuator , in order to ensure its reliable operation, use the imported fuel tank sealing ring , and set the buffer to protect the hydraulic valve , designed throttle Device, according to system requirements for control of driving external load , directly installed in the rack and pinion drive device. To better off valve with quick connect , quick fuel tank has done a series design , see " Table 2 . "
| Cylinder Specification | d | M | D1 | M1 | L1 | L2 | L3 | L | D | M2 |
|---|---|---|---|---|---|---|---|---|---|---|
| φ40/25 × 95 | 66 | M20 × 2 | 85 | M8 | 80 | 50 | 5 | 250 | 105 | M18 × 115 |
| φ40/25 × 126 | 66 | M20 × 2 | 85 | M8 | 80 | 50 | 5 | 280 | 105 | M18 × 115 |
| φ50/28 × 126 | 72 | M24 × 2 | 92 | M10 | 100 | 65 | 5 | 300 | 112 | M22 × 115 |
| φ50/28 × 157 | 72 | M24 × 2 | 92 | M10 | 100 | 65 | 5 | 350 | 112 | M22 × 115 |
| φ63/35 × 157 | 80 | M30 × 2 | 100 | M10 | 110 | 70 | 10 | 380 | 120 | M33 × 2 |
| φ63/35 × 189 | 80 | M30 × 2 | 100 | M10 | 110 | 70 | 10 | 420 | 120 | M33 × 2 |
| φ80/45 × 189 | 90 | M42 × 2 | 110 | M12 | 120 | 80 | 10 | 440 | 135 | M42 × 2 |
| φ80/45 × 220 | 90 | M42 × 2 | 110 | M12 | 120 | 80 | 10 | 480 | 135 | M42 × 2 |
2.2 The electrical control
According to the requirements of hydraulic control parts , electric control system to determine the parameters , see " Table 3 . "
| Parameter | Series 1 | Series 2 |
|---|---|---|
| Motor power P / kW | 1.1 | 1.5 |
| Switching Power Supply | 60W | |
| Control voltage | DC 24V | |
| Inlet Line | Three-phase four -wire AC 380V/AC 220V ± 10%, 2kW | |
| Control power | AC 220V ± 10% | |
Hydraulic drive fast off valve electronic control system designed using a special integrated circuit board, through rigorous testing to prove that the circuit board to facilitate adjustment , stable performance , reliable quality . Electronic control box from the switching power supply , AC contactors, thermal relays , circuit breakers, circuit boards and terminals, etc . Electrical control points common relay control box and two PLC type electronic control box .
3 for the model
Electro-hydraulic control drive model from the nine modules, used to show that the device code , the valve nominal diameter , valve nominal pressure , energy storage form, the form of fast valving , with hand movements , with the oil supply system, electric Options and product version number. Device models of nine units in the following order:
① Product Code – HGKG, electro-hydraulic control valve fast turn-off drive electro-hydraulic control unit ;
② valve nominal diameter – DN200, DN250, DN300, DN350, DN400, DN450, DN500, DN550, DN600, DN650, DN700, DN750, DN800, DN900, DN1000, DN1.00, DN1200, DN1300, DN1400, DN1500, DN1600, DN1800, DN2000;
③ Nominal pressure valves – PN6, PN10, PN16, PN20, PN25, PN40, PN50, PN63.3;
④ storage format – X for the accumulator type ( default option ), T for the spring -type ;
⑤ fast valving form – E to get power movement type ( default option ), D -type action for the loss of power ;
⑥ with manual movement – S ( storage -type use) ;
⑦ with oil-source systems – P ( spring -type use) ;
⑧ Electrical Options – PT for the general relay controlled (the default option ), XD is PLC controlled ;
⑨ product version number – 2X, 3X;
For example : HGKG① – 450②/06③ – X④ – E⑤ – S⑥/ P⑦ – PT⑧ – 2X⑨
4 Conclusion
Fast electro-hydraulic control valve off drive optimized for many times after the design is both remote control , can achieve local control box operation panel control . Imports through the use of low noise, high pressure gear pumps, high pressure and large flow of logic valves, compact screw cartridge valves and dedicated control circuit board , fast off rate up to 0.3s, and the stable and reliable operation .