Methods and systems to increase evaporator capacity

摘要

Embodiments to increase the capacity of the evaporator of a vapor-compression refrigeration system are described. The refrigeration system may be configured to have a first stage suction line heat exchanger and a second stage suction line heat exchanger. The refrigerant exiting the evaporator can be heated by the first heat exchanger. A thermal bulb of an expansion device, such as a thermostatic expansion valve (TXV) can be positioned downstream of the first heat exchanger. The thermal bulb is capable of regulating a variable volume of refrigerant through the expansion device in response to temperature changes. Thus, the superheat refrigerant vapor region in the evaporator can be reduced, thereby increasing the efficiency of the refrigeration system. The refrigerant exiting the evaporator is a liquid/vapor refrigerant mixture. The mixture can be vaporized to a refrigerant vapor in the first heat exchanger.

主权项

1. A refrigeration circuit comprising:
an evaporator; a condenser; an expansion device configured to provide a variable volume of refrigerant into the evaporator; a suction line heat exchanger including a liquid line inlet and a suction line inlet, the liquid line inlet configured to receive refrigerant from the condenser and the suction line inlet configured to receive refrigerant from the evaporator, the suction line configured to facilitate heat exchange between refrigerant flowing out of the condenser and refrigerant flowing out of the evaporator; a thermal control device configured to measure a temperature of the refrigerant at a measurement location downstream of the suction line inlet of the suction line heat exchanger; and a second suction line heat exchanger positioned downstream of the suction line heat exchanger; wherein the measurement location is between the suction line heat exchanger and the second suction line heat exchanger, wherein the thermal control device is configured to regulate the expansion device so as to regulate the variable volume of refrigerant, so that the refrigerant at the measurement location is in a superheat state.