What is the heat outflow when 2kg of dry saturated steam at 8.0 bar is converted into ice at -10°C
To determine the heat outflow when converting 2 kg of dry saturated steam at 8.0 bar into ice at -10°C, we need to calculate the heat required to cool down the steam from its initial state to -10°C, and then subtract the heat required to convert it into ice.
Here's how to calculate it step by step:
1. Determine the initial state of steam:
Dry saturated steam means that it is in a thermodynamic state where it is fully vaporized and in equilibrium with its liquid phase (water). At 8.0 bar, we can use steam tables to determine the corresponding temperature and enthalpy.
2. Find the temperature and enthalpy of the steam:
Use steam tables or a steam properties calculator to find the temperature and enthalpy of steam at 8.0 bar. Let's assume the temperature is T1 and the enthalpy is H1.
3. Calculate the heat required to cool down the steam to -10°C:
The specific heat capacity of steam is different from that of ice, so we need to consider the energy required to change the temperature of the steam from T1 to -10°C. The specific heat capacity of steam can again be found in the steam tables. Let's assume it is denoted by Cp1.
The heat required to cool down the steam can be calculated using the following formula:
Q1 = mass of steam * specific heat capacity of steam * (T1 - (-10°C))
4. Calculate the heat required to convert the steam into ice:
To convert the steam into ice, we need to remove the latent heat of vaporization from the steam. The latent heat of vaporization can also be found in the steam tables. Assume it is denoted by Lv.
The heat required to convert the steam into ice can be calculated using the following formula:
Q2 = mass of steam * latent heat of vaporization
5. Calculate the total heat outflow:
Finally, calculate the total heat outflow by adding Q1 and Q2:
Total heat outflow = Q1 + Q2
Note: In order to get accurate calculations, it's important to use accurate steam tables or reliable steam properties calculators to obtain the necessary values.
By following these steps and using the appropriate steam properties, you'll be able to determine the heat outflow when converting 2 kg of dry saturated steam at 8.0 bar into ice at -10°C.