Flash tank design and control for heat pumps

#The present disclosure relates to vapor injection systems and more particularly to an improved flash tank and control scheme for a vapor injection system.

#Scroll machines include an orbiting scroll member intermeshed with a non-orbiting scroll member to define a series of compression chambers. Rotation of the orbiting scroll member relative to the non-orbiting scroll member causes the compression chambers to progressively decrease in size and cause a fluid disposed within each chamber to be compressed.

#During operation, the orbiting scroll member orbits relative to the non-orbiting scroll member through rotation of a drive shaft, which is typically driven by an electric motor. Because the drive shaft is driven by an electric motor, energy is consumed through rotation of the orbiting scroll member. Energy consumption increases with increasing discharge pressure as the scroll machine is required to perform more work to achieve higher pressures. Therefore, if the incoming vapor (i.e., vapor introduced at a suction side of the scroll machine) is at an elevated pressure, less energy is required to fully compress the vapor to the desired discharge pressure.

#The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

#FIG. 1 is a perspective view of a flash tank in accordance with the principles of the present teachings;

#FIG. 2 is a cross-sectional view of a flash tank in accordance with the principles of the present teachings incorporating a baffle arrangement;

#The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

#Vapor injection may be used in air conditioning, chiller, refrigeration, and heat pump systems to improve system capacity and efficiency. Such vapor injection systems may include a flash tank that receives liquid refrigerant and converts the liquid refrigerant into intermediate-pressure vapor and sub-cooled liquid refrigerant. The intermediate-pressure vapor is supplied to a compressor while the sub-cooled liquid refrigerant is supplied to a heat exchanger. Supplying intermediate-pressure vapor to a compressor and sub-cooled liquid refrigerant to a heat exchanger improves the overall system capacity and efficiency of an air conditioning, chiller, refrigeration, and/or heat pump system.

#Vapor injection may be used in heat pump systems, which are capable of providing both heating and cooling to commercial and residential buildings, to improve one or both of heating and cooling capacity and efficiency. For the same reasons, flash tanks may be used in chiller applications to provide a cooling effect for water, in refrigeration systems to cool an interior space of a display case or refrigerator, and an air conditioning system to effect the temperature of a room or building. While heat pump systems may include a cooling cycle and a heating cycle, chiller, refrigeration and air conditioning systems often only include a cooling cycle, however, heat pump chillers, which provide heating and cooling cycle, are the norm in some parts of the world. Each system may use a refrigerant to generate the desired cooling or heating effect through a refrigeration cycle.