Functional Characteristics of Distributed Fiber Optic Heat Network Leakage Monitoring System
1. Continuous distributed measurement:
Distributed fiber optic sensors are truly distributed measurements that can continuously obtain measurement information along the detection fiber optic cable for tens of kilometers, greatly reducing false alarm and false alarm rates, and achieving real-time monitoring.
2. Anti electromagnetic interference, achieving on-site no electricity detection:
The optical fiber itself is composed of quartz material and is completely electrically insulated; At the same time, the signal of fiber optic sensors is carried by optical signals, which are inherently safe and not affected by any external electromagnetic environment interference. It can enter without being charged, thus eliminating the potential danger of electric sparks in areas containing combustible mixed gases, and achieving on-site non electric detection, which is inherently safe.
3. Intrinsic lightning protection:
Thunder often damages a large number of electrical sensors. Fiber optic sensors, due to their complete electrical insulation, can withstand the impact of high voltage and high current.
4. Long measurement distance, suitable for remote monitoring:
The two outstanding advantages of optical fiber are large data transmission volume and low loss. It can achieve remote monitoring for tens of kilometers without the need for relays.
5. High sensitivity and measurement accuracy:
In theory, the sensitivity and measurement accuracy of most fiber optic sensors are superior to general sensors, and this has been proven by mature products in practice.
6. Long lifespan, low cost, and simple system:
The normal working life of the fiber optic leakage monitoring device exceeds 20 years. After the completion of a construction project, maintenance free automated operation can be basically achieved, which can greatly reduce the annual operating and maintenance costs of the entire heating project, and achieve the state based maintenance and repair of the heating pipeline.
Distributed optical fibers can be applied in different scenarios, such as pipeline and tunnel leakage monitoring.
The necessity of distributed fiber optic heating network monitoring
In order to ensure the safe and reliable operation of the heating network and to keep track of its operation at all times, it is necessary to set up a monitoring system in the heating network. For directly buried heating networks, some countries have promoted the use of heating network leakage monitoring systems. The leakage of heating pipelines can easily lead to the loss of a large amount of water and heat energy, reducing the transportation efficiency of the heating system. At the same time, there are safety hazards in thermal pipelines: due to aging of pipelines, gas and water leaks occur, or due to accumulated water or a large amount of sewage gathering around the thermal pipeline after rain, continuous gasification forms a large amount of steam accumulation, which is difficult to evacuate. There have been varying degrees of thermal pipeline explosions both domestically and internationally.
During the use of thermal pipelines, they will be subjected to high temperatures, wear, physical and chemical effects, as well as disturbances from surrounding underground engineering construction and ground traffic dynamic loads. As a result, thermal pipelines will gradually develop defects such as cracks, deformation, and joint damage, leading to accidents such as fractures and leaks. In addition, the low welding quality between pipe sections, the pressure inside the pipeline exceeding its bearing range, and the corrosion damage of the steel pipe caused by water ingress into the insulation layer also seriously affect the safe operation of the thermal pipeline. Due to the high temperature of the heating medium, emergency rescue is often difficult, and the harm of hot water to other underground public facilities is also significant, making the losses difficult to estimate. Due to the lack of stable and reliable thermal pipeline state detection technology, the existing management mode lacks foresight, and many accidents are only discovered after pipeline damage. Therefore, it is extremely important for the safe operation of thermal pipelines to take preventive measures and timely grasp the status information of the pipeline.
Distributed fiber optic temperature measurement technology can continuously and accurately sense the spatial temperature field distribution along the sensing fiber optic, and the sensing fiber used has the advantages of small volume, light weight, simple structure, convenient use, high pressure and high temperature resistance, and electromagnetic interference resistance. It provides a new technical means for online temperature and leakage detection of thermal pipelines.
The distributed fiber optic temperature measurement system not only has the advantages of ordinary fiber optic sensors, but also has the ability to distribute temperature sensing at various points along the fiber optic line. The fiber optic is not only a conductor for transmitting information, but also a sensor for distributed measurement. It can continuously measure the temperature along the fiber optic cable, with a maximum measurement distance of over 20 kilometers. Each continuous temperature sensing segment and spatial positioning accuracy reach a high resolution of 0.4 meters, making it particularly suitable for applications that require large-scale and continuous temperature measurement.