What Heat Exchangers Will Be Used in the Flue Gas Denitrification Process

What heat exchanger will be used in the process of flue gas denitrification

Rotary air preheater

Structure principle: It is mainly composed of rotor, shell, sealing device, transmission device and other parts. The rotor is a rotatable cylinder with a large number of heat storage elements inside. When the flue gas passes through the rotor, the heat will be transferred to the heat storage element, so that its temperature rises; when the rotor rotates to the other side, the cold air passes through the heat storage element and absorbs the heat, thus realizing the heat exchange between the flue gas and the air.

Advantages: compact structure, small footprint; heat storage element has a large specific surface area, high heat exchange efficiency; able to adapt to a large range of flue gas flow and temperature changes.

Application Scenario: Widely used in the flue gas denitrification system of large-scale thermal power plants, often used as heat exchange equipment at the end of the boiler, used to preheat the combustion air, improve the combustion efficiency, and at the same time, reduce the exhaust temperature, reduce heat loss.

Plate Heat Exchanger

Structure Principle: A series of metal plates with corrugated shape are stacked, and a fluid channel is formed between the plates. The flue gas and the heated fluid flow in different channels and exchange heat through the plates.

Advantages: high heat transfer coefficient, due to the corrugated structure of the plate surface, so that the fluid in the channel to form a strong turbulence, enhancing the heat transfer effect; compact structure, covers an area of small; easy to disassemble, easy to clean and maintain.

Application Scenario: It is suitable for flue gas denitrification systems of various scales, especially in some occasions with high space requirements, such as industrial boilers, small thermal power plants, etc. It can be used to heat the reductant solution or other related fluids in the denitrification process.

Tube heat exchanger

Structure principle: It is composed of tube bundle, shell, tube plate, header, folding plate and other parts. The flue gas flows in the shell, and the heated fluid flows in the tube, and the heat is transferred through the tube wall. According to the different arrangement of the tube bundle, it can be divided into fixed tube plate type, floating head type, U-shaped tube type and other types.

Advantages: sturdy structure, can withstand high pressure and temperature; adaptable, according to different process requirements to choose different pipe and tube arrangement; easy to manufacture and maintenance.

Application Scenario: Widely used in flue gas denitrification system, it can be used to heat or cool all kinds of denitrification-related fluids, such as in some of the large power station boilers with selective catalytic reduction (SCR) denitrification technology, it is used to heat the reductant ammonia to the appropriate reaction temperature.

Heat pipe heat exchanger

Structural principle: It consists of a bundle of heat pipe tubes, which is a highly efficient heat transfer element and consists of a tube shell, a suction core and an end cap. The tube is filled with an appropriate amount of working liquid, when one end of the heat pipe is heated, the working liquid evaporates into steam, flows to the other end under the effect of pressure difference, and condenses into liquid when it is cold, and then flows back to the heated end through the liquid-absorbing core, and so on, to realize the transfer of heat.

Advantages: very high thermal conductivity, can quickly and effectively transfer heat; high heat exchange efficiency, and can realize the complete isolation of hot and cold fluids to avoid mutual pollution; simple structure, reliable operation, low maintenance costs.

Application Scenario: In flue gas denitrification, it can be used to recover the waste heat in the flue gas, heat the flue gas or other fluids entering the denitrification reactor, improve the efficiency of denitrification, and at the same time reduce the temperature of the flue gas to save energy, especially suitable for industrial kiln flue gas denitrification system with high requirements for waste heat recovery.