Influence of composite pipe sampling on the prevention of freezing and blocking of ammonia pipeline in flue gas denitrification system

Published on:

2023-02-16 16:19

The flue gas denitrification system of a thermal power plant is an important environmental treatment facility in the power generation system The stability of the denitrification system has a great impact on the protection of the atmospheric environment in the adjacent area. Take a power plant in South China as an example to see which heating method is suitable for flue gas denitrification system.

The ammonia hydrolysis urea production system is an important link in the flue gas system. The urea hydrolysis ammonia production system includes a urea dissolution tank, a urea solution pump, a urea solution storage tank, a feed pump, a hydrolyser, an ammonia buffer tank, and other equipment. The urea solution in the hydrolyser is hydrolyzed to ammonia, carbon dioxide, and water vapor under specified conditions such as temperature, pressure, and residence time, and after pressure adjustment is transported to the ammonia buffer tank.

The trachea heating method of the ammonia product was originally steam-powered. The denitrification system is unstable in operation, the ammonia gas is highly contaminated with water, the reaction efficiency of the denitrification catalyst is low. After the analysis, it is found that the main reasons are: the product line of the unit is long, and the heat preservation and heating effect of the pipeline is poor, resulting in the temperature of the product vapor dropping too much, and the volume of the product gas is very high. The product condenses after the temperature is below the dew point, there is a hidden danger of the ammonia and air mixing pipeline corrosion, and water and secondary air in the pipeline after the ammonia/air mixer to the SCR zone. After the ash powder is removed, ash deposits form, which will cause a serious blockage of the main injection pipe of denitrifying ammonia. Direct response to county authorities delays the efficiency of denitrification, resulting in unstable emissions of nitrogen oxides into flue gases, and also brings certain economic losses to the enterprise.

Therefore, the choice of heat preservation and heating method, which is better than steam, has become an important measure to prevent pipeline blockage. Thanks to comparative analysis, the composite sampling tube was even better.

An important element of the environmental monitoring system is the anti-corrosion heating composite pipe, consisting of a group of corrosion-resistant high-performance polymer pipes, supplemented by self-regulating electric heating cables or compensation cables Composite polyethylene (PE) protective jacket. The constant power parallel heating cable is a constant power heating cable. It is widely used to drain condensate, remove paraffin and keep oil and other pipelines heat, heat and keep Christmas trees at the oil field estuary, heat and heat preservation of chemical pipelines, tanks, tool pipelines, heating and hot water pipelines. Oil pipelines of offshore oil platforms Antifreeze, electric heating and insulation of medium pipelines in port oil depots and antifreeze for water pipes.

The total capacity per unit length of the constant power parallel single phase heating cable is constant, and the longer the heating cable used, the greater the power output. The heating cable can be cut arbitrarily according to actual needs in place (at least one heating section is reserved), it is flexible and can be laid close to the surface of the pipeline. The braided layer of the outer layer of the electric heating cable can play the role of heat transfer and heat dissipation, improve the overall strength of the heating cable, and can also be used as a protective ground wire. The three-phase constant power also has the following advantages: the maximum allowable use of a heating cable with the same power length is three times longer than that of a single-phase constant power heating cable, Large cross section and large conductivity area, which can improve transmission efficiency.

Latest News

Please search according to your needs.