A heat balance can be achieved in a heat exchanger with a cooling fluid and a condensing fluid at constant temperature by applying the principles of thermodynamics, specifically the concept of enthalpy changes during phase changes. The equation (m*Cp*ΔT)fluid 1 = (m*Cp*ΔT)fluid 2 is used to relate the mass flow rates and specific heat capacities of both fluids. The heat of vaporization or condensation is critical in this scenario, as it allows for energy transfer without a change in temperature for the condensing fluid. Understanding these principles is essential for accurately modeling heat exchangers in thermodynamic systems.
PREREQUISITESStudents studying thermodynamics, engineers designing heat exchangers, and professionals involved in thermal system optimization will benefit from this discussion.
You are aware that enthalpy changes at constant temperature for a phase change of a single component substance, correct? You've heard of the heat of vaporization/condensation, correct?Kqwert said:Homework Statement
If you have a heat exchanger with a cooling fluid and a fluid that condenses, and the fluid condenses over the entire heat exchanger i.e. its temperature is constant. How can one make a heat balance in such a case, when dT is 0 for the condensing fluid but not the other? i.e. (m*Cp*Dt)fluid 1 = (m*Cp*Dt)fluid 2
Homework Equations
The Attempt at a Solution
I wasn't aware that the enthalpy changes at constant temperature for a phase change.Chestermiller said:You are aware that enthalpy changes at constant temperature for a phase change of a single component substance, correct? You've heard of the heat of vaporization/condensation, correct?
Are you taking thermodynamics now, or have you had it yet?Kqwert said:I wasn't aware that the enthalpy changes at constant temperature for a phase change.
I haven´t had it yet. We had a small brief on it in the course I am taking, but maybe I didn't pay enough attention.Chestermiller said:Are you taking thermodynamics now, or have you had it yet?
Well, I'm sure you know that water boils at a constant temperature of 100C while you are adding heat.Kqwert said:I haven´t had it yet. We had a small brief on it in the course I am taking, but maybe I didn't pay enough attention.