What is a common cause of liquid slop over in an ammonia refrigeration system?

Liquid slop over in an ammonia refrigeration system occurs when there is an excess of liquid refrigerant entering the evaporator compared to the amount that can be effectively vaporized. Under normal operation, the evaporator is designed to saturate a specific amount of liquid refrigerant, converting it to vapor while absorbing heat. However, when there is an overfeeding of liquid refrigerant, it can overwhelm the evaporator's capacity to vaporize it, leading to liquid refrigerant carrying over into the suction line of the compressor.

This situation can cause a range of operational issues, including compressor damage due to liquid slugging, reduced cooling efficiency, and potential system failure. Managing the flow of refrigerant and ensuring the system operates within design parameters is critical to maintaining efficient and safe operation.

The other options, while they can impact system performance, do not directly lead to liquid slop over in the same manner that overfeeding does. For instance, underfeeding may not provide enough refrigerant for efficient operation, low refrigerant temperature can indicate other issues but doesn't directly cause slop over, and excessive compressor speed can affect overall system balance but typically does not directly relate to liquid slop over without an accompanying overfeed of liquid.