Oil line control system

The present application provides a refrigeration system. The refrigeration system may include a suction header, a compressor, a suction header oil return line in communication with the suction header and the compressor, and an oil line control system. The oil line control system may include a sensor and a valve to open and shut the suction header oil return line in response to the sensor.

TECHNICAL FIELD

The present application and the resultant patent relate generally to refrigeration systems and more particularly relate to refrigeration systems including an oil line control system so as to automatically shut off an oil return line when liquid refrigerant floods a suction header and the like so as to prevent compressor damage therein.

BACKGROUND OF THE INVENTION

Modern air conditioning and refrigeration systems provide cooling, ventilation, and humidity control for all or part of a climate controlled area such as a refrigerator, a cooler, a building, and the like. Generally described, a conventional refrigeration cycle includes four basic stages to provide cooling. First, a vapor refrigerant is compressed within one or more compressors at high pressure and high temperature. Second, the compressed vapor is cooled within a condenser by heat exchange with ambient air drawn or blown across a condenser coil by a fan and the like. Third, the liquid refrigerant is passed through an expansion device that reduces both the pressure and the temperature of the liquid refrigerant. The liquid refrigerant is then pumped within the climate controlled area to one or more evaporators. The liquid refrigerant absorbs heat from the surroundings in an evaporator coil as the liquid refrigerant evaporates to a vapor. Finally, the vapor refrigerant returns to the compressor and the cycle repeats. Various alternatives on this basic refrigeration cycle are known and also may be used herein.

Current design trends in refrigeration systems focus on increased efficiency, reduced energy consumption, and other types of environmentally friendly improvements. Similarly, other design goals may focus on reducing the overall complexity and costs typically found in modern refrigeration systems. There is thus a desire for improved refrigeration systems with respect to efficiency, energy usage, complexity, and costs.

SUMMARY OF THE INVENTION

The present application and the resultant patent thus provide a refrigeration system. The refrigeration system may include a suction header, a compressor, a suction header oil return line in communication with the suction header and the compressor, and an oil line control system. The oil line control system may include a sensor and a valve to open and shut the suction header oil return line in response to the sensor. The sensor may be a temperature sensor that detects the presence of a cooler liquid refrigerant therein.

The present application and the resultant patent further provide a method of protecting a compressor from a flow of liquid refrigerant. The method may include the steps of monitoring a temperature of a fluid in an oil return line extending between a suction header and the compressor, determining a temperature drop in the fluid in the oil return line, and closing the oil return line until the temperature of the fluid in the oil return line increases.

The present application and the resultant patent further provide a refrigeration system. The refrigeration system may include a suction header, a compressor, a suction header oil return line in communication with the suction header and the compressor, a temperature sensor positioned about the suction header oil return line, and a valve to open and shut the suction header oil return line in response to the temperature sensor.

DETAILED DESCRIPTION

Referring now to the drawings, in which like numerals refer to like elements throughout the several views,FIG. 1shows an example of known refrigeration system10. The refrigeration system10may be used to cool any type of a climate controlled area or a refrigerated space. The refrigerated space may be a refrigerator, a cooler, a building, and the like. The refrigeration system10may include a flow of a refrigerant15. The refrigerant15may include conventional refrigerants such as hydrofluorocarbons, carbon dioxide, ammonia, and the like. Any type of refrigerant may be used herein.

The refrigeration system10may include an evaporator assembly20. The evaporator assembly20may include one or more evaporator coils25and an evaporator fan30. The evaporator assembly20may be positioned within or adjacent to the refrigerated space to provide cooling therein. The refrigeration system10may include a suction header35. The suction header35may store and distribute the refrigerant15as required. The suction header35may flow the refrigerant15to an accumulator or directly to one or more compressors40via one or more refrigerant lines17. Specifically, the suction header35may be in communication with a suction port45on each compressor40. The compressors40compress the flow of refrigerant15and forward the flow to a condenser assembly50via a discharge port55. The condenser assembly50may include on or more condenser coils60and a condenser fan65. The condenser fan65pulls ambient air over the condenser coils60for heat exchange with the refrigerant. The refrigerant15then may flow to an expansion valve70before being returned to the evaporator assembly20so as to repeat the cycle herein. The refrigeration system10described herein is for the purpose of example only. Many other types of refrigeration systems, refrigeration cycles, and refrigeration components may be used herein.

The compressors40herein may require a source of oil in communication with the flow of the refrigerant15. An oil separator75may be positioned downstream of the compressors40. Any oil that may be trapped in the refrigerant vapor downstream of the compressors40may be removed therein. A removed flow of oil80then may be returned to the compressors40via an oil return line85. Moreover, any oil80that remains in the flow of the refrigerant15may eventually settle within the suction header35. A suction oil return line90thus may return the oil80to the compressors40or to the refrigeration line17upstream of the compressors40. Other components and other configurations may be used herein.

FIG. 2shows an oil line control system100as may be described herein. The oil line control system100may include a suction header oil return line110. The suction header oil return line110may extend from the suction header35to one or more of the compressors40or to the refrigeration line17upstream of the compressors. The suction oil return line110may include a solenoid valve120thereon. The solenoid valve120may be a conventional on/off type flow control valve. Other types of flow control valves may be used herein. The solenoid valve120normally may be in the open position. The suction header oil return line110also may include a ball valve130or other type of manual control valve. The ball valve130may be manually operated to open and close the suction header oil return line110as needed. The suction header oil return line110also may include a Schrader valve140. The Schrader valve140may be a conventional pneumatic valve so as to clear the line via air pressure if necessary. Other type of clearing access ports and clearing devices also may be used herein.

The oil line control system100also may include a temperature sensor150. The temperature sensor150may be positioned on the suction oil return line110or elsewhere to determine the temperature of the refrigerant15and/or changes in the temperature of the refrigerant15. The temperature sensor150also may be located inside the suction header35or along the exterior thereof. The temperature sensor150may be of conventional design. More than one temperature sensor150may be used herein. The temperature sensor150may be in communication with the solenoid valve120and a controller160. The controller160may be any type of programmable logic device. The controller160may be local or remote. Other components and other configurations may be used herein.

The oil line control system100thus prevents damage to the compressors40if liquid refrigerant15in the suction header35enters the suction header oil return line110. If the liquid refrigerant15enters the suction header oil return line110, the temperature sensor150provides an alarm triggered by a lower than normal temperature therein. A predetermined temperature may be used and/or the temperature may depend upon other types of operational parameters. The solenoid valve120thus closes to prevent the liquid refrigerant15from flowing to the suction port45of the compressor40. Similarly, the controller160may reopen the solenoid valve120and the suction header oil return line110when the temperature sensor150indicates a temperature increase. Such a temperature increase may indicate that the refrigerant15has boiled off. Likewise, a predetermined temperature may be used and/or the temperature may depend upon other types of operational parameters. The oil line control system100then may return to normal operation. Different types of heating sources, such as an electric heater, a hot gas bypass heater, and the like, also may be employed to assist in boiling off the liquid refrigerant15in the suction header35. Other components and other configurations may be used herein.