In the large-scale natural gas pipeline transportation industry, due to the very long distance between the natural gas production site and the end user, hundreds need to be laid
Even thousands of kilometers of transmission pipelines. The transportation of natural gas in the pipeline needs to maintain a certain pressure, so every few kilometers or tens of intervals are required
To establish a compressor station, the pressure of natural gas in the pipeline should be ensured by a special high-power natural gas compressor. The main road is attached to the living area of each province and city
In the near future, it is necessary to establish a distribution station to transport natural gas to the feeder pipeline through the distribution station and finally reach the end user.
The main road, branch pipelines, compressor stations, and distribution stations form a huge and orderly natural gas transmission pipeline network.
Due to the wear or aging of components during the use of the compressor, it will cause natural gas leakage, which will be caused by a certain gas concentration
The explosion seriously endangers the life safety of the staff in the station and the normal use of equipment. At the same time, the boiler room of each distribution and compressor station is due to the use
There is also a risk of natural gas leakage in natural gas power generation. In addition, various fuels are stored in the refined oil warehouses of each distribution and compressor station
Hazard of flammable gas leakage.
The natural gas pipeline has a long transmission distance, and the pipeline and various compressor and distribution stations are located in remote areas far away from the city, with logistics support and design
Preparation and maintenance difficulties. At the same time, most of the gas-producing countries around China and China's gas-producing areas are concentrated in the central and western regions of Asia, and natural gas pipelines
The road stretches from the gas-producing area to the eastern coastal region, covering the whole of China. The ambient temperature ranges from -40°C in Northeast China and Inner Mongolia to Guangdong,
Xiamen's +55°C high temperature (station temperature). From the dry environment of Xinjiang and Gansu to the salty and wet environment of the seaside area. Ring of the gas pipeline industry
The environment puts forward the most stringent requirements for the adaptability of the equipment used to the environment.
As can be seen from the introduction of the natural pipeline industry, in the natural gas pipeline industry, the main gas detected is methane-based flammability
gas. The main testing locations are the natural gas compressor plants of each compressor station, as well as the boiler rooms and refined oil warehouses of each compressed gas distribution station.
The main component of natural gas is methane, which is a flammable and explosive gas that is lighter than air. According to the petroleum and petrochemical industry specifications, the detector is indoors
The installation position is generally a corner of the wall, which is convenient for detecting the natural gas that has accumulated together. The installation height of the detector is generally 30~50cm from the top of the wall.
For a large space like a compressor plant, combustible gas detectors need to be installed in all four corners. And for boiler rooms, refined oil warehouses
In such a small storage room, only two combustible gas detectors are required. The combustible gas detector is mounted diagonally.
The structure of a typical gas alarm control system for a compressor station is as follows:
3-wire system, 4-20mA signal
3-wire system, 4-20mA signal
Fire alarm control cabinet
220VAC input
System57
Fire alarm controller
Relay signal (high report high high report
Fault) - to the station system
Senspoint XCD
Combustible gas detector
Safe area
Explosion-proof area
Optima Plus
Combustible gas detector
Typical natural gas pipeline line
Gas alarm system diagram
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Honeywell Gas Detection Industrial Product Application Brochure ·
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As shown in the figure above, the combustible gas detector in the field can be either the Optima Plus type combustible gas detector or the XCD-IR type flammable gas
detector。 The combustible gas detector detects the concentration of flammable gas in the field (explosion-proof area).
A fire alarm control cabinet is installed in the cabinet room (safe area), and a System57 fire alarm controller is installed in the cabinet. System57
The gas alarm controller not only provides the power supply of DC24V to the field detector, but also accepts the 4-20mA analog signal delivered by the field detector.
Each control card and one detector in the field of the System57 gas alarm controller form an independent detection loop, each of which can be output
There are 3 relay signals: High Alarm (A1), High High Alarm (A2), and Fault. In addition, according to some special requirements, System57 gas
The alarm controller can also output a 4-20mA signal per loop, or a Modbus signal to the station control system.
Due to the harsh working environment in the natural gas pipeline industry, maintenance is difficult, and once natural gas leaks, the situation can be very dangerous. These factors,
Very high requirements are placed on the stability, reliability and safety of field instruments and systems. Therefore, combustible gas detectors on site are selected
Choose a combustible gas detector with an infrared absorption compensation detection principle, and also require the detector to have SIL2 safety level certification. For example,
Optima Plus combustible gas detector and XCD-IR combustible gas detector. The detector of the infrared absorption compensation detection principle has a response
It is very suitable for the advantages of fast speed, high accuracy, stable and reliable work, small drift, long service life, no oxygen participation, no poisoning, etc
Environmental and working conditions requirements in the natural gas pipeline industry.
In order to improve the safety and reliability of the system, in addition to selecting a high-reliability field detector, the system generally needs to have an independent backup power
Source System (UPS). When the system loses power, the system can maintain normal operation for a period of time (2~8 hours) and can send out a power failure signal.
Since each station is located in the open area of the principle city, it is easily affected by lightning strikes. Therefore, in the natural gas pipeline industry, they are all required
Both the on-site detector and the controller in the control cabinet are equipped with surge protectors.
Due to the limitations of the size of the station, the scale of gas alarm systems in the natural gas pipeline industry is very small. The average distribution station has only 2~4 flammable gases
The larger compressor station also has only 16~20 combustible gas detectors. Therefore, the general gas alarm system will be the same as the flame alarm system,
The fire alarm system is integrated to form an independent, compact, safe, efficient and reliable fire alarm system.
Honeywell sensepoint XCDfixedgas detector
Honeywell Searchpoint Optima Plus Spot Infrared Fixedgas Detector