Hey, I can answer both of those!
When you store refrigerant in a receiver, you have the potential to lose a bit (or a lot) of any subcooling that you might have got from the condenser (or you did not get any to start with). As the TXV's are in the remote units, you _need_ 8 to 10C subcooling to ensure you have a solid column of liquid at the TXV, so they use some refrigerant in a tube-in-tube heat exchanger to subcool the liquid as it leaves the receiver. As they are aiming for maximum efficiency, even this loop is controlled by an EEV.
The "bleed" doohickey is the oil return from the oil-separator into the suction line. Under some conditions it's possible for refrigerant to condense in the oil separator, so the capilliary is there to ensure it evaporates before it hits the compressor. Once things are up to temperature, the bypass solenoid opens to make it easier for the oil to return.
Someone over are refrigeration-engineer.com pointed me at that diagram. I keep it open in a firefox tab as I find it fascinating. Someone has spent a lot of money engineering a solution that is as efficient as possible with the minimum number of parts, so I like trying to figure out what each bit does and why it must be required.
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