Flash tank economizer
AssigneeCarrier Corporation
InventorsRichard G. Lord, Mark R. Rabbia, Kevin J. Glover
Life of this patent
Estimating the term…
Abstract
A flash tank economizer containing a first expansion device to expand high pressure refrigerant from a system condenser to an intermediate pressure and a second expansion device for further expanding liquid refrigerant at the intermediate pressure that has collected in the tank to a desired low pressure for delivery to the system evaporator. Vapor phase refrigerant produced by the first expansion in the tank is injected back into the system compressor at the intermediate pressure.
Claims26
A method of expanding a high pressure liquid refrigerant from a condenser of a refrigeration system to a lower pressure and temperature for delivery to the system evaporator that includes the steps of
- carrying out a first expansion of high pressure refrigerant from a system condenser within an economizer tank to bring said refrigerant to an intermediate pressure and temperature,
- separating the liquid refrigerant from the refrigerant vapor in said economizer tank after said first expansion,
- carrying out a second expansion of the separated liquid refrigerant in said tank to bring the separated refrigerant to a desired low pressure and temperature, and
- delivering said twice expanded low pressure refrigerant to a system evaporator.
Apparatus for expanding liquid refrigerant from a high pressure to a low pressure as the refrigerant moves between the condenser and the evaporator of a refrigeration system that includes
- an economizer tank having a sump and an inlet for receiving high pressure liquid refrigerant from the condenser
- a first expansion means in said economizer tank for expanding the high pressure liquid refrigerant to an intermediate pressure so that liquid phase refrigerant is collected in the sump of said tank and vapor phase refrigerant is collected in the top section of said tank over said sump,
- a second expansion means for further expanding the liquid refrigerant collected in the sump of said tank to a desired low pressure, and
- means for delivering the low pressure refrigerant to the evaporator of said system.
A flash tank economizer for use in a refrigeration system containing a condenser which is connected to an evaporator by a liquid line and a motor driven screw compressor for raising the pressure of refrigerant vapor generated in the evaporator to a high pressure and delivering the high pressure vapor to the condenser, said flash tank economizer including
- a vertically disposed tank connected into the liquid line having an inlet in the bottom wall thereof for receiving high pressure liquid refrigerant from the condenser,
- an inlet tube vertically positioned inside said tank that is connected to said inlet for bringing high pressure liquid refrigerant from the condenser to an electronically controlled expansion valve, said tank having an upper section for collecting vapor phase refrigerant and a lower sump for collecting liquid phase refrigerant,
- control means associated with said regulating said valve electrically controlled expansion valve for expanding high pressure liquid refrigerant to an intermediate pressure inside said tank in response to one or more sensed system parameters whereby the expanded liquid phase refrigerant is collected in the sump and vapor phase refrigerant is collected in the upper section of the tank,
- a stand pipe mounted vertically in the bottom wall of the tank which surrounds the inlet tube to provide an expansion chamber therebetween,
- means for connecting the expansion chamber to the inlet of said evaporator,
- at least one vertically disposed slotted opening formed in said stand pipe for placing the sump of said tank in fluid flow communication with the expansion chamber whereby liquid refrigerant passing through said slotted opening is expanded a second time to a low pressure,
- a gate means slidably mounted over said slotted opening for varying the size of said opening, and
- float means arranged to float on the liquid refrigerant contained in the sump of said tank, said float being connected to said gate to vary the size of said opening in response to the level of liquid refrigerant in said sump.
Dependencies are inferred from the claim text.