Final answer:
Purging a double-pipe condenser should be performed from the top, near the gas inlet, to effectively remove non-condensable gases which rise due to their lower density.
Step-by-step explanation:
Purging a double-pipe condenser should be done carefully to maintain the efficiency of a refrigeration system. When purging a double-pipe condenser, it's important to remove non-condensable gases that could impair the heat transfer process.
The best place to purge these gases is from the top, near the gas inlet, because non-condensable gases tend to accumulate at the highest points within the system due to their lower density compared to the refrigerant.
In the cycle of refrigeration, the electrically driven compressor increases the temperature and pressure of the gas before it enters the condenser coils.
Here, heat is transferred to the surrounding environment, causing the gas to condense into a liquid. The condensed liquid then travels through a pressure-reducing valve and reaches the outdoor evaporator coils, where it is cooled.
Identifying the condenser's role is crucial for understanding where to purge. The condenser is the component where the gas is transformed into a liquid.
Thus, the correct answer to the question of where to purge a double-pipe condenser is from the top, near the gas inlet.