Mobile CNG Refueling Station

2 configuration list for CNG MRU skid

3 Technical data sheet for dispenser

4 configuration list for dispenser

5 technical data sheet for CNG discharging post

6 configuration list for discharging post

1 Skid design

All the components are installed on the same skid container including hydraulic oil tank, motor, oil pump, instrument, buffer device, heat ex-changer, heat dissipation system, valve body connecting pipe, gas discharge column, gas storage system, dispenser, electrical control system and other equipment. The connection pipeline between the equipment and the fixing of the equipment and the base are detachable connections. Therefore, this type of compressor is extremely convenient for transportation, installation, operation and maintenance.

2 Skid safety designation

2.2.1 High-pressure components such as high-pressure cylinders with integrated skids are made of high-quality forged steel to eliminate internal stress and perform mechanical performance tests and ultrasonic flaw detection tests as required. Ensure long-term stable and reliable operation of the product in harsh environments.

2.2.2 We choose pressure vessel components as per standard "GB 150.2-2011 steel pressure vessel "or equivalent ISO9809 standard.

2.2.3 High pressure pipeline material: 06Cr19Ni10 stainless steel pipe, complying with "GB/T14976-94 high pressure pipeline " or equivalent ASME standard.

3 Lubrication system

The unique design of compressing cylinder and cylinder oil free lubrication guarantee no pollution to the gas even the seal leaked. It saves lubrication oil and guarantees the gas clean.

4 Cooling system

The integrated skid use water circulating air cooling system. The air-cooled radiator uses fin-type high-efficiency stainless steel tubes, so that compressed gas and hydraulic oil at all levels can be fully cooled after passing through the cooler. The cooling medium is in areas where the outside temperature is below zero in winter, and an appropriate temperature antifreeze is selected according to the temperature. The cooling medium cools hydraulic oil and compressed natural gas. The cooling medium is cooled by the integrated air-cooled heat sink.

5 Filtration system

1) The precision of the integrated skid inlet filter is 50 μ m, which removes particulate impurities and moisture to ensure the purity of the natural gas entering the integrated skid.

2) No filter is required at the equipment outlet. Because the piston adopts oil-free lubrication process, the unique sealing structure of the oil cylinder guarantees

This proves that there is no possibility of mixing oil and gas, and zero pollution to natural gas is achieved during the compression process.

3) Full-size stainless steel ball valve is installed at the inlet of the integrated skid hydraulic pump, and an oil return magnetic filter is set at the oil return port. The accuracy is 10 μ m, which is effective filter out metal and particulate impurities.

6 Safety valve relief and maintenance relief system

The venting pipes of all levels of the compression system are collected at the compressor outlet venting manifold to lead the skid. The venting pipe is provided with a manual bypass valve in front of the safety valve to facilitate maintenance.

7 Noisy deduction system

The frame structure is conducive to space saving and equipment heat dissipation. The skid has the function of sound insulation, noise reduction and rainproof; the main frame of the box is made of square steel and channel steel by bolts; the inner layer is made of multiple layers of sound insulation and sound absorbing materials. Absorb high-frequency noise, block the transmission of low-frequency noise, prevent panel vibration, etc., effectively prevent the noise from being transmitted to the environment during equipment operation.

1 Electrical configuration

A. The cables between the main motor and the explosion-proof control box and the explosion-proof transfer box on the skid body are regularly routed through galvanized steel pipes. All other cables are routed through plastic-clad metal hoses. , Vibration, corrosion area.

B. The connection between each cable and electrical equipment adopts strict explosion-proof isolation and sealing measures,and explosion-proof plastic-clad metal hoses are used to protect the connection.

C. Each cable uses a whole line without a connector in the middle.

D. The incoming end of the power distribution cabinet supporting the integrated skid has an anti-surge protector. The distribution cabinet has the function of receiving external control contacts, such as flammable gas detection alarm signals and station control ESD signals, which can cut off the power supply of the compressor unit when the accident is alarmed, at the same time cut off the power supply of the fire-fighting solenoid valve, and cut off the connection of various process pipelines. Reduce the scope of the accident.

E. Integrated cooling fan motor electric control device and PLC (24-point input, 16-point + extended 8-point output, 12-channel analog input, 2-channel analog output, system redundancy 10%). Inside its explosion-proof box.

2 PLC function control system design

A. start up

PLC program logic control: Power-on self-inspection equipment operating conditions-Host computer displays self-inspection status-Judging the status of the control panel-Opening the inlet and outlet electric control valves-Cooling cycle and automatic fan temperature control startup-Oil pump startup- Automatically judge dynamic data-normal range of inlet and outlet air pressure-compressor starts normally.

B. normal operation

PLC program logic control: The program control valve group first chooses to supply gas to the high pressure pipeline; when the pressure of the high pressure pipeline reaches the specified pressure (20-25.0MPa adjustable), it automatically switches to the middle pressure pipeline for gas supply; When the pressure of the pressurized pipeline reaches the specified pressure (20-25.0MPa adjustable), the system automatically stops.

The trailer is used as a low-pressure unit to supply gas, and the residual gas of the trailer can be quickly discharged through the control of the station process valve, reducing the logistics cost.

C. Accident alarm

PLC program logic inspection: abnormal intake pressure, exhaust pressure, upper computer display, audible and visual alarm, Internet remote monitoring.

PLC program logic control: When the air intake pressure, exhaust pressure, hydraulic system pressure, oil temperature, cooling system, gas leakage exceeds the alarm and fault set values, the upper computer displays the alarm and fault content, sound and light alarm, or protective shutdown .

E. External signal interface

The PLC control system must have an external emergency stop signal interface, and the signal source is the station-controlled ESD switch signal.

Reserved communication expansion interface: RS422 / RS485 interface, supports standard MODBUS protocol, and Internet interface supporting TCP / IP protocol.

F. System software

Provide station process software, equipment operation control software, host computer software, transportation service software.

Free software upgrade service for life.

3 Composition of equipment management control system

A. System Components

Adopts PLC automatic programming control, which is composed of standard PLC electrical control system, soft start, host computer industrial computer (touch screen), A / D converter, pressure transmitter, temperature and level sensor, position transmitter, and combustible gas probe Sensor, solenoid valve, etc .; can realize automatic operation interface, remote monitoring on the Internet.

The unit control PLC system consists of an explosion-proof slave station explosion-proof box on the skid base and a master station operation cabinet inside the skid. The compressor control box can complete the automatic start and stop of the compressor oil pump motor, intake, exhaust program control valve group, cooler fan, compression cylinder operation, etc., and complete its interlock control. The explosion-proof control box on the skid and the touch screen on the skid are used for data exchange, which can automatically complete all daily control functions such as startup, alarm information, and emergency stop. And can display the cylinder piston position, intake and exhaust pressure curve.