This refers to the section where two or more streams mix. the mixing chamber does not necessarily have to be a distinct chamber. Mixing chambers can also be referred to as direct-contact heat exchangers.
An ordinary T-elbow or a Y-elbow in a shower serves as the mixing chamber for the hot and cold streams as shown below:
Considering the Y-elbow mixing chamber above with negligible kinetic and potential energies, the energy equation simplifies as follows:
Example
It is desired to produce
a water stream at 35°C by mixing a hot water stream at 60°C with a stream of
cold water at 20°C. If the mass flow rate of the hot water stream is 0.5 kg/s,
determine the mass flow rate of the cold-water stream. Assume all the streams
are at a pressure of 300 kPa.
Solution 1
Solution 2
Note that the enthalpy of a compressed liquid can be approximated as the enthalpy of saturated liquid at the given temperature. Therefore, from Appendix B (Table B.1) from M.D Koretsky, Engineering and Chemical Thermodynamics, Wiley, 2004.
No comments:
Post a Comment