Electric accompanied by tropical for flue gas desulphurisation pipeline reason

　　In the environmental protection requirements are becoming more and more strict today, flue gas desulphurisation system has become a coal-fired power plants, iron and steel mills and other industrial facilities standard equipment. These systems, conveying limestone slurry, gypsum slurry and other media of the pipeline is facing special heat preservation challenges, electric accompanied by the application of the tropical is to solve these special working conditions under the technical difficulties.

　　Flue gas desulphurisation pipeline medium has easy to precipitate, easy to crystallise characteristics. Limestone slurry in the low temperature environment viscosity rises sharply, gypsum slurry in the temperature is lower than 10 ℃ is easy to precipitate crystallisation, these changes will lead to pipeline circulation cross-sectional area is reduced, or even completely blocked. The actual operation data of a power plant shows that the desulphurisation slurry pipeline without heat tracing measures occurs 2-3 times a month on average in winter, and each time the treatment needs to be shut down for 4-6 hours, resulting in huge economic losses. The introduction of electric accompanied by the introduction of tropical effectively maintain the pipeline temperature of the medium, so that it is always maintained at 15-25 ℃ of the best flow interval, completely solve this problem.

　　Corrosion protection is electric accompanied by tropical application in desulphurisation pipeline is another important reason. Desulphurisation system in the medium usually contains chloride ions, sulphide and other strong corrosive components, ordinary carbon steel pipeline corrosion rate will be significantly accelerated in a low-temperature humid environment. Electric accompanied by the tropical through the maintenance of pipeline wall temperature higher than the dew point temperature, effectively prevent the formation of condensate, thus significantly reducing the risk of corrosion. Specially designed corrosion-resistant electric accompanied by heat adopts polyperfluoroethylene propylene (FEP) outer sheath, can resist the chemical erosion in the desulphurisation medium, to ensure long-term reliable operation of the system.

　　Energy saving and environmental protection considerations also promote the application of electric accompanied by heat tape in the desulphurisation system. The traditional steam accompanies the heat to need to pump the steam from the power plant, not only affects the power generation efficiency, but also increases the carbon emission. The electric accompanies the heat system to use the electric energy directly, the energy conversion efficiency is as high as 95% above, and can realise the precise temperature control, avoids the energy waste. In the carbon peak, carbon neutral policy background, this kind of clean accompanying heat way is more in line with the green development requirements.

　　Process stability demand is also a key factor in the choice of electric heat tracing. The operation efficiency of desulphurisation system directly affects the final emission index, while the fluctuation of pipeline temperature may lead to the change of chemical reaction rate, affecting the effect of desulphurisation. The electricity accompanies the heat system to cooperate with the PID temperature controller, can the pipeline temperature fluctuation control in ±1℃ range, for the desulphurisation chemical reaction provides the stable temperature environment. Monitoring data show that the use of electric accompanied by heat insulation desulphurisation system, its SO2 emission concentration fluctuation range than steam accompanied by heat system narrowed by 60%, emission indicators more stable and reliable.

　　The convenience of installation and maintenance is also an important reason for selecting electric accompanying heat for desulphurisation pipeline. Desulphurisation system is usually complex layout, pipeline direction changeable, steam accompanied by heat need to lay complex steam pipe network and hydrophobic system, construction difficulty. The electric accompanies the heat tape to have the installation flexible characteristic, can easily adapt to the various complex direction, especially suitable for the transformation project. In terms of maintenance, electric heat tracing system basically realises maintenance-free operation, while steam heat tracing needs regular maintenance of traps, dealing with leakage and other problems.

　　Safety enhancement is also the choice of electric heat tracing points of consideration. Desulphurisation area usually exists corrosive gas, belongs to the typical dangerous environment. The low surface temperature design of the electric heating cable, together with the explosion-proof junction box and grounding protection, fully comply with the electrical safety standards for hazardous areas. Steam tracing systems, on the other hand, carry the risk of scalding at high temperatures, and piping leaks may cause secondary contamination.

　　The demand for intelligent control further consolidates the advantageous position of electric trace heating. Modern desulphurisation system generally adopts DCS centralised control, electric trace heating system can be seamlessly integrated into the automation system to achieve remote monitoring and intelligent adjustment. Through the linkage with the efficiency parameters of desulphurisation, the electric accompanying heat system can automatically optimise the operation temperature and minimise the energy consumption under the premise of guaranteeing the process requirements. An intelligent power plant project practice shows that this intelligent heat tracing way makes the desulphurisation system overall energy consumption reduced by 12%, at the same time improve the operation reliability.

　　Electric accompanies the tropical belt in the flue gas desulphurisation pipeline application, is the perfect combination of technical development and engineering needs of the model. From solving the medium characteristic problem to enhance the system energy efficiency, from guaranteeing the safe operation to realise the intelligent control, the electricity accompanies the heat technology for the desulphurization system to provide the omni-directional solution. Along with the environmental protection standard continues to improve and the power industry digital transformation of the depth, electricity accompanies the tropical in the field of desulphurisation application will continue to expand, for win the blue sky defence war to provide strong technical support.