60 cubic meter LNG storage tank

Technical and Quotation Proposal for Liquefied Natural Gas (LNG) Storage Tanks

RMB unit; (10,000 RMB)

Serial Number

Name

Specs and Models

Quantity

Unit Price

Price

Note

1

Low-temperature LNG storage tank

CFL-60/0.8

(23T Maximum Liquid Capacity)

1 unit

37.3

37.3

Vertical; group seating support.

Note: This quotation is after tax, excluding shipping costs.

Production Cycle: Shipment ready within 15 days of contract生效.

Payment Terms: 30% deposit upon contract signing, with the remaining balance due in full before shipment.

Vessel Color: Base coat is polyurethane paint, top coat is white acrylic magnetic paint, with two coats of each.

60m3 Vertical LNG Storage Tank Technical Specifications:

Container Category: Type II

Structure Type: Horizontal

Insulation Method: Vacuum Powder Insulation (Pearlescent Sand)

Medium: LNG (Liquefied Natural Gas)

Design Temperature: Inner Shell: -196℃   Outer Shell: -20-50℃

Design Pressure: 0.84 MPa                Outer Shell: -0.1 MPa

Maximum Working Pressure: 0.8 Mpa             Outer Shell: -0.1 MPa

Volume: 60 m³                   Effective Volume: 54 m³

Material: Inner Shell: S30408               Outer Shell: Q345R

Specs: Inner Shell: ?2500×11310×10/10; Outer Shell: ?3000×12110×10/12

Total Length: 24,260 kg; Sandwich Layer Spacing: 250mm; Inner Tube Material: S30408

Insulation Material: TCHP-50 Pearl Sand  Filling Quantity: >52.2 m³

Internal bladder pneumatic test: Medium: Nitrogen; Test Pressure: 0.96 Mpa

Valves; Low-temperature stainless steel stop valves.

Sealing vacuum degree: ≤5 Pa

Static evaporation rate ≤ 0.2%/d

Vacuum sandwich leakage air release rate ≤ 2×10-6 Pa.m3/s

Manufacturing Acceptance Standards; GB150-2011, "Capacity Regulations", GB/T18442-2011

Tank Pipeline Valve Instrument List (Domestic High-Quality Products):

Serial Number

Name

Specs

Quantity

Manufacturer

1

Low-temperature long-handled ball valves

DN50

6 sets

Furui Special Equipment Co., Ltd.

2

Low-temperature long handle ball valve

DN10

1 set

Furui Special Equipment Co., Ltd.

3

Three-way ball valve

DN25

1 set

Furui Special Equipment Co., Ltd.

4

Safety valve

DN25

2 sets

Furui Special Equipment Co., Ltd.

5

Detonation Sheet

DN25

2 pieces

Shanghai Huali

6

Level Differential Pressure Gauge

1 set

Sichuan Xinlan Stone or Lan Stone

7

Vacuum Valve Assembly

DN50

1 set

Sichuan Xinlan Shi or Lanshi

8

Oxygen Pressure Gauge

0-1.0MPa

1 piece

Chengdu Tianwei Instrument Factory

Huzhou Boiler Factory Co., Ltd.

LNG Gasification Plant Major Equipment

LNG Storage Tank

Tanks are the main equipment of LNG liquefaction stations, accounting for a significant portion of the construction cost. The design of tanks should be given high priority.

1.1 Material Selection for LNG Tanks

The working temperature of the LNG tank during normal operation is -162.3°C; it must be cooled to -196°C before the first use.

Liquid nitrogen pre-cools the tank, making the design temperature of the tank -196°C. The inner tank must withstand both the working pressure of the medium and the low temperature of LNG, requiring the inner tank material to have excellent comprehensive mechanical properties at low temperatures, particularly good low-temperature toughness. Therefore, the inner tank material is 0Crl8Ni9, which is equivalent to ASME (American Society of Mechanical Engineers) standard 304.

The outer shell material of the atmospheric pressure vessel is selected as low-alloy structural steel Q345R, low-carbon steel Q245R, and Q235B.

1.2 Assume Design Responsibility

Tapping ports on the inner tank of the storage tank include: upper liquid inlet, lower liquid inlet, liquid outlet, vapor outlet, level measurement port, upper level gauge port, lower level gauge port, and 8 process manholes. All the tapping ports on the inner tank are made of 0Cr18Ni9 material.

For easy regular measurement of vacuum and evacuation, a vacuum evacuation port is provided on the bottom cover of the outer casing (the port is sealed after evacuation). To prevent vacuum failure and the leakage of the inner casing medium into the outer casing, a pressure relief device is installed on the top cover of the outer casing.

2. Unloading Vehicle Booster Vaporizer

Due to the absence of pressure boosting equipment on the LNG tank trucks, an onboard gasification booster with a capacity of  m3/h is installed at the station to increase the tank truck pressure to 0.6 MPa. The temperature of the LNG entering the gasifier is -162.3°C, while the temperature of the gaseous natural gas exiting the gasifier is -145°C.

3. Storage Tank Pressure Vessel Aerator

After filling a 100m³ LNG tank with 90m³ of LNG, calculate the pressure increase from 0.4 MPa (卸车状态) to 0.6 MPa (工作状态) in the 10m³ gas phase space within 30 minutes. According to the calculation, one 200m³/h capacity atmospheric temperature gasifier is selected for each tank to boost pressure. The temperature of LNG entering the booster gasifier is -162.3°C, and the temperature of the gaseous natural gas exiting the booster gasifier is -145°C.

Designs commonly feature one LNG tank paired with one booster gasifier. Multiple tanks can also share a single or a set of gasifiers for boosting, with the process simplified through valve switching, reducing equipment and lowering costs.

4. Air-cooled vaporizer

The air-temperature vaporizer is the main vaporization facility for LNG gasification stations to supply gas to the city. The vaporization capacity of the vaporizer is determined based on the peak-hour gas consumption, with a certain margin, usually set at 1.3 to 1.5 times the peak-hour gas consumption. They are typically grouped in sets of 2 to 4, with 2 to 3 sets designed for alternating use.

5. Water Bath Vaporizer

When the ambient temperature is low and the outlet temperature of the air-cooled vaporizer is below 5°C, a water bath natural gas heater is connected in series after the air-cooled vaporizer to heat the natural gas after vaporization [5, 6]. The heating capacity of the heater is determined as 1.3 to 1.5 times the peak hour gas consumption.

6. BOG Heater (Boil Off Gas)

Essentially an air-temperature vaporizer

The design capacity of the BOG air temperature heater is calculated based on the largest quantity of gaseous natural gas after unloading from the reclaiming tank trucks, with the unloading time for gaseous natural gas set at 30 minutes. Taking a 40m³ tank truck with a pressure drop from 0.6MPa to 0.3MPa as an example, the required capacity of the BOG air temperature heater is calculated to be 240m³/h. Generally, the BOG air temperature heater is selected based on the number of tank trucks that can be unloaded simultaneously at the gasification station. Typically, the heating capacity of the BOG heater ranges from 500 to 1000m³/h. During winter, water bath natural gas heaters are used, with BOG serving as fuel for hot water boilers, while the rest is sent into the urban transmission and distribution network during other seasons.

7. BOG Buffer Tank

For peak-shaving type LNG liquefaction stations, to recover excess gas from unloading trucks during off-peak periods and BOG (Boil Off Gas) from storage tanks, or for natural gas blending stations to achieve uniform blending, a BOG buffer tank is often added at the outlet of the BOG heater. Its capacity is set according to the recovered excess gas from the trucks.

8. Safety Discharge Gas (EAG) Heater

The EAG air temperature heater equipment capacity is calculated based on the maximum safe venting volume of a 100m3 storage tank. The calculated safe venting volume for the 100m3 storage tank is 500m3/h, and a single air temperature heater with a gasification rate of 500m3/h is selected in the design. The incoming gas temperature to the heater is -145°C, and the outgoing gas temperature is -15°C.

9. Pressure Regulation, Metering, and Odorization Equipment

Select pressure regulating devices based on the scale of the LNG gasification station. Typically, a two-way pressure regulating device is set up, with self-contained regulators featuring controllers and over-pressure cut-off.

Metering is done using a turbine flow meter. The odorant used is tetrahydrothiophene, and it is added by a diaphragm metering pump powered by the flow signal, injecting the odorant into the gas pipeline.

Filter

Structural Features of Filters

The station uses a mesh core filter for filtering out particulate impurities and water from the outgoing natural gas. The filter cores are replaceable, and the removed cores (made of stainless steel mesh) can be reused after cleaning. The filter is equipped with a pressure gauge that indicates the pressure difference between the inlet and outlet of the filter, indicating the degree of clogging of the filter core. The precision of the filter cores is generally selected as 50um, and the volume of the water collection chamber is greater than 12% of the filter's volume.