What is a desulfurization flue gas heat exchanger and what are its characteristics?

The flue gas heat exchanger in a desulfurization system is a heat exchange device that uses the heat of a high-temperature fluid to heat a low-temperature fluid. The heat pipe in a heat exchanger generally consists of a shell and tube, and a working fluid (the working fluid) within. The shell and tube are made of steel and are sealed to a vacuum. The working fluid is a specially treated liquid.

The heated side of the heat pipe absorbs heat from the high-temperature fluid, which is then transferred through the heat pipe wall to the working fluid within. After absorbing heat, the working fluid boils and evaporates, turning into steam. The steam, under the influence of a pressure differential, rises to the heat-releasing side. Cooled by the low-temperature fluid outside the pipe, the steam condenses and releases its latent heat of condensation, allowing the low-temperature fluid to gain heat. The condensate then returns to the heated side by gravity. This cycle repeats, transferring heat from the high-temperature fluid to the low-temperature fluid, heating it.

Because the interior of a heat pipe is generally evacuated to a certain vacuum, the working fluid easily boils and evaporates, allowing the heat pipe to start up very quickly, resulting in high thermal conductivity. Compared to metals like silver, copper, and aluminum, heat pipes can transfer several orders of magnitude more heat per unit weight.

Working characteristics of flue gas heat exchanger - desulfurization flue gas heat exchanger

Compared with conventional heat exchange equipment, heat pipe technology has the following important characteristics:

(1) Heat pipe heat exchange equipment is safer and more reliable than conventional heat exchange equipment and can operate continuously for a long time. Conventional heat exchange equipment generally uses inter-wall heat exchange, and the cold and hot fluids flow through the two sides of the wall respectively. If there is a leak in the pipe wall or the wall, it will cause production losses. The heat exchange equipment composed of heat pipes is a secondary inter-wall heat exchange, that is, the hot fluid must pass through the evaporation section and condensation section of the heat pipe to transfer to the cold fluid. It is generally impossible for the heat pipe to be damaged at the same time in the evaporation section and the condensation section, so the reliability of the equipment operation is greatly enhanced;

(2) High heat transfer efficiency. The cold and hot sides of the heat pipe can use winding fins to increase the heat transfer area as needed;

(3) Effectively avoid the cross-flow of cold and hot fluids. Each heat pipe is a relatively independent closed unit. The cold and hot fluids flow outside the pipe, and the cold and hot fluids are completely separated by the intermediate sealing structure;

(4) Effectively prevent dew point corrosion by adjusting the number of heat pipes or the heat transfer area ratio between the hot and cold sides of the heat pipes to increase the wall temperature of the heat pipes above the dew point temperature;

(5) Effectively prevent dust accumulation by using a variable cross-section design to ensure that the fluid flows at a constant velocity through the heat pipe heat exchanger, achieving the purpose of self-cleaning;

(6) There are no rotating parts, no additional power consumption, and no need to frequently replace components. Even if some components are damaged, normal production will not be affected;

(7) Damage to a single heat pipe will not affect other heat pipes, and the impact on the overall heat exchange effect can be ignored.