I have a seemingly simple question
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There is a reactor containing half water; the pressure inside the reactor is 2.0 mPa (gauge pressure). It is heated to 200°C, and oxygen is introduced into the reactor to maintain an oxygen partial pressure of 0.5 MPa. After reaching equilibrium, is the water vapor in the kettle superheated vapor? At this point, water is placed in a flash tank under a pressure of 1.0 MPa; will the water boil at this time? Will the generated steam be saturated steam? At 200 degrees Celsius, the saturated vapor pressure of water is approximately 1.55 MPa (absolute pressure)
The water vapor ahead is not superheated vapor; as long as there is no heat loss during the depressurization process, the water vapor is saturated vapor.
It’s hard to say, because the temperature of steam at 1.0 MPa should be around 181–185 degrees, while the temperature of your water is 200 degrees; it’s not clear whether the heat from these 200 degrees can provide enough latent heat for vaporization
In my understanding, no saturated steam is generated within the equipment, nor is there any superheated steam; instead, water boils in the flash tank at 1.0 MPa, thereby producing steam
In my understanding, no saturated steam is generated within the equipment, nor is there any superheated steam; instead, water boils in the flash tank at 1.0 MPa, thereby producing steam
As long as the system reaches gas-liquid equilibrium, it must be saturated steam; when water is placed in a flash tank, it will definitely boil, and once equilibrium is achieved, the steam is also saturated steam. The so-called superheated steam is produced by further heating dry saturated steam.
There is half water inside the tank; under such conditions it is impossible for all of it to turn into steam. In other words, a external heat source is needed to keep heating the tank, and there is still some liquid water left in it (equivalent to 20 kgf of steam condensate). The temperature of this liquid water is higher than 200 degrees, as the required pressure is 20 kgf. In other words, the two conditions of “pressure inside the kettle at 2.0 mPa (gauge pressure) and heating to 200°C” are contradictory to each other; only one of them can be satisfied, and this has nothing to do with whether oxygen is added or not! As for the second question, it is feasible; it’s equivalent to using the sensible heat of water to replace latent heat. In actual production, the waste heat from the condensation of high-pressure steam is often used to generate low-pressure steam, but it is necessary to control the pressure properly.