Questions about heat transfer? ?

To calculate the heat required for water to change from a certain temperature to saturated steam, the concept of enthalpy is usually needed. Enthalpy is a thermodynamic state function that represents the heat content of a system; it is related to the system’s pressure, temperature, and amount of substance. The process of water turning into saturated steam generally involves the following stages: 1. Heating liquid water to its boiling point (that is, the saturation temperature at that pressure). The heat required at this stage can be calculated using the following formula: \ Where \( Q_1 \) is the heat needed to heat the water to its boiling point, \( m \) is the mass of water, \( c \) is the specific heat capacity of water, \( T_{\text{sat}} \) is the saturation temperature, and \( T_{\text{initial}} \) is the initial temperature. 2. At the boiling point, latent heat is supplied to convert water completely into saturated steam. This latent heat is known as the heat of vaporization, and is usually denoted by \( h_{\text{fg}} \). For saturated steam at a specific temperature, the latent heat of vaporization is a constant value that can be obtained from tables. The corresponding heat calculation formula is: Therefore, the total amount of heat required for water at 250°C and 319°C to turn into saturated steam is respectively: To determine the exact amount of heat needed to convert water into saturated steam at these two temperatures, it is necessary to know the mass of the liquid water initially, the specific heat capacity of water, as well as the saturation temperatures and vaporization heats at those two temperatures (which can be found by referring to tables of thermodynamic properties of water). Generally, water at higher temperatures requires less total heat to be absorbed in order to turn into steam in the same state, as it already possesses a higher initial thermal energy. However, this also depends on the changes in the specific heat capacity and latent heat of vaporization of water at high temperatures. Usually, these values need to be looked up in a table, as they change with temperature and pressure. In practice, such detailed data can be obtained from tables of thermodynamic properties or software, such as Steam Tables and Thermodynamic Properties of Substances. .

The saturated steam is in the drum, and as water is continuously supplied to the boiler, the water in the boiler turns into saturated steam condensate

There’s also ice at over 400 degrees;P

It seems you know too little about water; you’re such a stubborn person

Isn’t it just about looking at latent heat? I remember that the higher the temperature, the lower the latent heat of vaporization.

Okay, thank you. In our process, n-butane is oxidized to produce maleic anhydride; molten salts are used to remove the heat generated by the oxidation reaction, thereby producing 30 kilograms of saturated steam at a temperature of around 250°C. Subsequently, the saturated steam is subjected to pressure buildup, with the pressure being increased to 110 kilograms and the temperature reaching around 319°C. During this pressure buildup process, less heat is removed from the oxidation reaction; if no adjustments are made, the temperature inside the reactor will rise. Is that right? I have another question: if, under the same feed load of n-butane, the heat released during the reaction is the same, then after this pressure buildup process is complete, does the amount of steam also decrease? ?

Okay, thank you. In our process, n-butane is oxidized to produce maleic anhydride; molten salts are used to remove the heat generated by the oxidation reaction, thereby producing 30 kilograms of saturated steam at a temperature of around 250°C. Subsequently, the saturated steam is subjected to pressure buildup, with the pressure being increased to 110 kilograms and the temperature reaching around 319°C. During this pressure buildup process, less heat is removed from the oxidation reaction; if no adjustments are made, the temperature inside the reactor will rise. Is that right? I have another question: if, under the same feed load of n-butane, the heat released during the reaction is the same, then after this pressure buildup process is complete, does the amount of steam also decrease? ?

It’s over 250; consider the latent heat – at lower temperatures, the latent heat is higher, so more heat is required