Question about Multiple Stream Mixings into Units

AI Thread Summary
The discussion revolves around thermodynamic analysis involving a condenser and a feed-water heater with multiple streams. The user has defined one stream entering the condenser but lacks information on the other two streams, leading to challenges in balancing the multi-stream units. They assume all streams enter and exit at the same pressure and that the exit stream is a saturated liquid. Key concepts mentioned include adiabatic mixing points, equal pressure inlets, and the heat exchanger properties where enthalpy equals heat transfer (Q). The user seeks guidance on effectively performing unit balances in this context.
royblaze
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Homework Statement



I'm currently doing some thermodynamic analysis. I don't know where to put this question, but here goes:

I have a system that has two streams entering a condenser, and one leaving. I don't know mostly anything about two of the streams.

One stream I have fully defined via other unit balances. I am making an assumption: all streams entering the condenser must be the same pressure, and as a result, so too must the exit stream. The exit stream is a saturated liquid, from the question.

I am making this same assumption on a feed-water heater, which has two streams in, and two streams out. One of the streams leaves as a saturated liquid to a throttler, whose exit stream goes back to the condenser.

The feed-water heater's other outlet stream goes to a boiler, and then to a two turbine system, where between the two turbines, one stream goes to the feed-water heater. The second turbine's outlet goes to the condenser.

I'm having a real tough time trying to balance the multi-stream units. This is an intro to thermodynamics class with one of the worst lecturers in history. We have learned how to balance units when one stream enters and then exits. We have not learned anything about units that have multiple streams entering.

So far, we have learned that mixing points are adiabatic with equal pressure inlets. We also know that heat exchangers (which I assume the condenser and feed-water heater are) do no work, and the enthalpy is equal to Q.

Could I just get a few tips/facts about how to go about this unit balance?

Here's a picture. See attached:
 

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I have solved the question after clarifying some assumptions that were not given to us.
 

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