I have a question regarding heat balance
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I’ve encountered a heat balance issue recently and would appreciate everyone’s guidance. First, 1 ton of liquid material at a temperature of -10°C and a pressure of 0.3 Mpa is placed in a metering tank. The tank is then heated using steam until the pressure rises to 1.6 Mpa; this pressure is maintained as the material is fed into the reaction vessel for processing. I would like to calculate the amount of steam required. Initially, I thought that the heat provided by the steam should be sufficient to convert the liquid material at -10°C into saturated vapor at 1.6 Mpa, based on the enthalpy change associated with this process. I’m not sure if this approach is correct How should the energy balance of this system be conducted? I ask for the guidance of all teachers
Is 0.3 MPa the liquid pressure at the beginning? ? It’s vapor pressure, right?
Study*study*, so what is the temperature at 1.6 MPa?
Is there a enthalpy value at the corresponding temperature? If it exists, it’s easy; or, if there is a heat capacity, the latent heat can be calculated indirectly as well.
First: During the rise in pressure from 0.3 MPa to 1.6 MPa in your metering tank, does the liquid inside undergo any phase change? Is there any temperature rise? If there is a phase transition, what is the phase transition temperature? For safety, the enthalpy at low temperature can be multiplied by the phase change volume plus the sensible heat change ； Secondly: when calculating steam consumption, it is also necessary to assume the temperature and pressure at which phase change of the steam occurs, in order to calculate the steam usage based on the enthalpy change at the saturated temperature under that pressure. I hope this helps you. If you have any further questions, feel free to contact me!