Composition Characteristics Study on The Pyrolysis Gas Products of Substation Control Cables under Fire

Synchronous thermal analyzer, tube furnace flue gas analyzer and gas chromatography-mass spectrometry (GC-MS) are used to study the combustion simulation experiment of control cable in substation. In the experiment, different gas atmosphere and heating rates are selected to simulate the combustion conditions in different scenarios of actual fire. The results show: in term of pyrolysis characteristic, the main components of the control cable (outer sheath, inner sheath and insulating layer) have one or two weightlessness stages during pyrolysis in nitrogen atmosphere, and two or three weightlessness stages during pyrolysis in air atmosphere. Due to the existence of oxidation reaction, the mass fraction of the control cable pyrolysis residues in nitrogen atmosphere is generally higher than that in air atmosphere; In term of gas product, the inorganic products mainly include CO, CO2, HCl and H2O. Under the condition of sufficient oxygen supply, CO2 and CO are the majority. The yield of CO2 is usually more than 10 times that of CO, and the yield of HCl is only 20% that of CO. Organic products mainly include benzene series, and its yield ranges from 0.0001 to 0.04g/g. According to the analysis of pyrolysis gas products’ composition, the pyrolysis gas products of control cables have certain toxicity and corrosiveness, and have certain risks to the safety of personnel and environment under fire.