MF-4.5/(3-7) -250 type M, micro-oil lubrication, air-cooled, reciprocating piston CNG compressor is a mature technology product, the machine has less energy consumption, low noise, low vibration, high reliability, easy operation, and other characteristics.
This machine mainly comprises a public chassis, compressor host, explosion-proof power frequency motor, gas path system (including separation, and safety release unit), lubrication system, operating instrument system, and electrical system. All the equipment (non-explosion-proof PLC control cabinet, non-explosion-proof frequency conversion starting cabinet installation, and distribution room) is integrated on the standard base and installed indoors/outdoors.
Technical requirements for the compressor:
Process requirements
Compression Medium: Natural gas (dry gas after desulfurization and dehydration)
Nominal volume flow:4.5M³/min
Compressor suction Pressure: 0.3 ~ 0.7MPa(G)
Compressor discharge pressure:25.0MPa (G)
Cooling Mode: Air cooling
Suction Temperature of the: 0 ~ 40 ° C
Compressor Control Mode: Manual start, automatic shutdown if a fault occurs
Usage Conditions
Ambient Temperature: -20°C to +40°C
Installation Mode: Indoor installation/outdoor installation
Power Supply: 380V/50Hz
Altitude: ≤1000m
Main technical parameters of a compressor:
| 1 | Type | MF-4.5/(3-7）-250 |
| 2 | Host structure form | M-type, four-column, four-stage, first-stage double-acting/second-stage double-acting /Three or four double-order difference |
| 3 | Compression medium | Natural gas (dry gas after desulfurization and dehydration) |
| 4 | Nominal volume flow | 4.5m3/min |
| 5 | rate of flow | 950～1950Nm3/h |
| 6 | Suction pressure (gauge pressure) | 0.3～0.7MPa |
| 7 | Inspiratory pressure (gauge pressure) Rated exhaust pressure (gauge pressure) | 25.0MPa |
| 8 | suction temperature | 0～40℃ |
| 9 | Gas delivery temperature | ≤ Ambient temperature +15 ° C |
| 10 | type of cooling | forced air cooling |
| 11 | Lubricating Method | Cylinder and packing oil lubrication; The crankshaft, connecting rod, and cross head are lubricated by an oil pump. |
| 12 | Lubricating oil temperature | ≤70℃ |
| 13 | travel of piston | 105mm |
| 14 | mean piston speed | 3.45m/s |
| 15 | shaft power | ≤339kW |
| 16 | the rotational speed of the compressor | 985r/min |
| 17 | Be powered | Explosion-proof motor: 355kW, SF1.05, 985r/min, AC380V/50Hz, IP55, B3, dⅡBT4 |
| 18 | type of drive | Coupling, motor drive |
| 19 | intensity of vibration | ≤18.0mm/s |
| 20 | Detection and control mode | Transmitter detection, PLC control, touch screen display |
| 21 | Automatic control signal | Automatic control signal oil pressure, first intake pressure, last exhaust pressure, exhaust temperature, etc |
| 22 | seal form | Medium body and packing seal |
| 23 | operating mode | continuous |
| 24 | Compressor dimensions (length × width × height) | ~ 7000×3300×3300mm (based on actual design and manufacture) |
| 25 | Total machine weight | ～23000kg |
| 26 | The service life of the compressor unit | More than 20 years |
The design, manufacture, inspection, and installation of the unit shall adopt the latest version as the execution of this technical Agreement. The compressor can be automatically protected.
The compressor is equipped with a high-reliability programmable controller. The pressure transmitter and temperature transmitter of the compressor provide various working parameters such as pressure and temperature to PLC so that PLC can continuously monitor the working condition.
Parameters are displayed by text or touch screen, remote monitoring operation can be performed, timely and flexible control, advanced and reliable performance.
Startup mode: frequency conversion startup (power frequency operation)
Unit characteristics
All parts of the MF-4.5 / (3-7) -250 CNG compressor unit are integrated into the skid-mounted base to form an integral skid-mounted compressor station. Host machine structure: M – type, four-column, four-level compression.
The motor of the unit is connected to the crankshaft through the elastic coupling. When the crankshaft is driven by the motor for rotating motion, the piston is driven in the cylinder for reciprocating linear motion for gas compression. Then the cooling system is connected with the compressor at all levels by the piping system, which forms the potential energy conversion of electric-kinetic energy and gas.
The unit mainly has the following characteristics:
（1）The unit adopts an integrated design from the overall layout, all equipment is integrated on the skid, and takes full account of the convenience of operation and maintenance, so the floor area is small, and the overall layout is beautiful and reasonable;
（2）The basic parts choose basic parts of 6.5 tons of piston force products, which play an important role in the performance and operation reliability of the compressor;
（3）Adopt the M-shaped structure with good motion balance, the unit has small vibration and smooth operation;
（4）Compressor piston ring, supporting ring, packing, and valve using domestic famous brands, greatly prolonging the service life of important parts such as wearing parts;
（5）The piston rod is hardened by the surface of the packing part, and the hardness and wear resistance is enhanced by ion spraying treatment;
（6）The compressor is provided with a safety valve, which can be opened and unloaded when the pressure exceeds the standard to ensure the safe operation of the system;
（7）The compressor oil pan is equipped with an electric heater to ensure the normal use of the equipment in winter;
（8）The compressor adopts PLC programmable controller control, advanced automatic protection, low and high intake pressure, high exhaust pressure at the end, low oil pressure and automatic shutdown program monitoring operation, timely and flexible control, high degree of automation, advanced and reliable performance;
（9）Siemens PLC reserved an RS485 communication interface to provide remote transmission of the compressor running state and parameter signals to the DCS system (communication protocol is Modbus protocol). The operation parameters of the whole set of compressor equipment are not only on site
（10）The display on the control cabinet can also be transmitted to the display of wireless communication equipment (mobile phones, etc.), which can realize 24-hour monitoring.
Material of main parts: fluorine rubber is used for the O-ring.
The above is to MF-4.5/(3-7) -250 type M CNG compressor a basic product introduction!