Final answer:
During the re-expansion phase of the compressor cycle in a heat pump or refrigeration system, the suction valve is open to allow for the entry of the refrigerant into the compressor, while the discharge valve is closed to prevent backflow.
Step-by-step explanation:
Understanding Compressor Cycle and Valve Operations
During the compressor cycle specifically concerning re-expansion, the behavior of the suction valve and the discharge valve becomes critical to the operation of HVAC systems. When discussing the re-expansion phase, which can be viewed as part of the exhaust or low-pressure side, it is important to note that the suction valve should be open to allow the refrigerant to enter the compressor. At the same time, the discharge valve should be closed to prevent backflow and maintain the directionality of the refrigerant cycle.
In the context provided, detailing the cycle within a heat pump or refrigeration cycle, the relevance of the valve positions during re-expansion is paramount to ensure efficient system performance. Once the refrigerant is compressed and subsequently cooled in the condenser, it passes through the expansion valve where the pressure is reduced, and then it is ready to be re-admitted into the evaporator through the open suction valve. The discharge valve remains closed to keep the high-pressure side of the cycle separated from the low-pressure side.