What are the main functions of an LNG vaporization and pressure regulation station?

The LNG (liquefied natural gas) vaporization and pressure regulation station is a critical facility in the natural gas transmission and distribution system. Its core function is to convert low-temperature liquid natural gas into gaseous natural gas and adjust it to the pressure required by urban pipelines or end-users. Below is a detailed explanation of its primary functions:

1. LNG Vaporization Function
Liquid to gas:
The LNG vaporization and pressure regulation station heats the cryogenic (-162°C) liquid natural gas through vaporizers, converting it into ambient-temperature gaseous natural gas. This process is a prerequisite for LNG to enter urban gas pipelines.
Gasification method:
Ambient air gasifier: Utilizes natural heating from the surrounding air, suitable for warm regions or small-scale gasification.
Water-bath vaporizer: Heated by hot water or steam, suitable for cold regions or large-scale vaporization.
Forced vaporization (BOG heater): Process the evaporated gas (BOG) from storage tanks to prevent excessive pressure buildup.
2. Pressure Regulation Function
Pressure regulation:
The pressure of the gasified natural gas is adjusted from high pressure (e.g., 4.0 MPa) to medium pressure (e.g., 0.4 MPa) or low pressure (e.g., 0.01 MPa) to meet the requirements of urban pipeline networks or industrial users.
Voltage regulation method:
Multi-stage pressure regulation: Achieve gradual pressure reduction through series-connected regulators to ensure stability.
Backup pressure regulation: Install a backup pressure regulator to ensure continuous gas supply.
3. Filtration and Purification Function
Impurity Removal:
By removing solid particles, moisture, and oil contamination from natural gas through filtration, it prevents pipeline blockages and equipment corrosion.
Quality Assurance:
Ensure that natural gas complies with national standards (such as GB 17820 "Natural Gas") to safeguard user safety.
4. Odorization function
Leak detection:
Add an odorant (such as tetrahydrothiophene) to natural gas, giving it a noticeable distinctive smell to facilitate timely detection in case of leaks.
Safety requirements:
Comply with the requirements of the "Code for Design of Urban Gas" (GB 50028) to ensure public safety.
5. Measurement function
Flow measurement:
Accurately measure natural gas flow using flow meters (such as turbine flow meters and ultrasonic flow meters) to provide a basis for trade settlement and gas supply management.
Data Monitoring:
Real-time recording of traffic data, supporting remote monitoring and data analysis.
6. Safety Protection Function
Overpressure Protection:
Install safety valves and venting devices to automatically release pressure when it exceeds the set value, preventing equipment damage or explosions.
Leak detection:
Install a combustible gas detector to monitor natural gas concentration in real time, triggering alarms and initiating emergency measures.
Emergency shut-off:
In the event of a leak or fire, automatically or manually cut off the gas supply to prevent the accident from escalating.