Superheated steam is used to heat the flue gas; the amount of superheated steam required is calculated and controlled. Urgent! Urgent! Urgent! ! !
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The flue gas at 45°C is heated to 85°C using superheated steam at 1.0 MPa and 290°C; after heat exchange, the steam parameters become 0.6 MPa and 200°C, and a 2205 finned tube heat exchanger is used for this process. Is such heat exchange possible? How should the parameters of the exhaust steam be controlled? Usually, the temperature and pressure reduction of steam is achieved through a temperature and pressure reducer plus water. Can indirect heat exchange achieve this as well? Some supplementary elements still need to be added.
This post was last edited by lupg on 2021-10-31 at 10:01. 1. The original poster’s question specifies two requirements for steam: a decrease in pressure and a decrease in temperature. 2. Since the steam has not yet undergone phase change, pressure reduction is achieved through throttling principles, such as using throttle valves or orifice plates; if pressure reduction is to be accomplished via the resistance of a heat exchanger, the tube spacing must be very small, resulting in high flow velocities. 3. The temperature decrease is determined through heat balance, that is, the steam flow rate is determined by the enthalpy difference required to raise the temperature of the flue gas. 4. It is theoretically possible to meet these two requirements using finned tube heat exchangers, but this may not be practical due to issues such as noise and vibration associated with high flow velocities. 5. Using steam to reduce pressure first is also not complicated.
It should be possible to implement high-temperature steam exhaust pipes. Check the standards related to pressure vessels; such temperatures and pressures require higher standards for manufacturing.
It depends on whether you want to maintain the steam outlet temperature or the flue gas outlet temperature; if you want to maintain one, use that as the signal source to adjust the flow rate of B, and vice versa.