Heater for heat exchange

The temperature of saturated steam remains constant when the pressure is stable, whereas the temperature of superheated steam at the same steam pressure varies with the degree of superheating. If the temperature of the steam is unstable, it leads to instability in the heat transfer temperature difference across the heat exchanger. According to the heat transfer equations, the amount of heat transferred will change, making control difficult. Therefore, in chemical production, it is generally required that the steam used in heat exchangers be saturated steam. The steam coming out of the boiler can be superheated steam or high-pressure steam, in order to reduce losses due to the condensation of some of the steam as a result of heat loss during transportation through the steam pipes; its degree of superheating is generally determined based on the level of heat loss. Near the centralized steam supply points used in the plant, saturated steam can be obtained by reducing temperature and pressure, thereby achieving the steam temperature and pressure required for the process.

My personal understanding: 1. The latent heat and sensible heat differ significantly in terms of value (they have different units), and under certain conditions, more heat is provided by latent heat. 2 Heated using latent heat, with stable temperature and easy control. This post was last edited by LTY on 2007-12-14 10:13]

I think there are several points: 1) The heat transfer coefficient of saturated steam is much higher than that of superheated steam and water; 2) The latent heat of steam is also much greater than the sensible heat of water; 3) Superheated steam places higher demands on equipment. These factors determine that saturated steam should be used instead of water or superheated steam

If that’s the case, wouldn’t it be better to utilize the sensible heat of the saturated condensate after using up the latent heat of the steam?

The heat released during latent heat release is generally an order of magnitude higher than that of sensible heat, right?

At 1 standard atm, the latent heat is about 6 times that of the sensible heat; as pressure increases, the proportion of latent heat decreases. Additionally, the process of steam condensation (condensation phase change) is an efficient heat transfer process; therefore, latent heat is used in design and selection calculations. Of course, it is also possible to consider the recovery of the condensed water (at the corresponding saturation temperature), in terms of both thermal energy and water – but that represents another complex issue.