US 12,241,670 B2
Multi-compressor system with normally-open valves in oil balancing connections
Thierry Legay, Nordborg (DK); and Patrice Bonnefoi, Nordborg (DK)
Assigned to DANFOSS COMMERCIAL COMPRESSORS, Trevoux (FR)
Filed by Danfoss Commercial Compressors, Trevoux (FR)
Filed on Mar. 13, 2023, as Appl. No. 18/182,764.
Claims priority of application No. 22/02955 (FR), filed on Mar. 31, 2022.
Prior Publication US 2023/0314048 A1, Oct. 5, 2023
Int. Cl. F25B 7/00 (2006.01); F04B 41/06 (2006.01); F04C 2/02 (2006.01); F04C 11/00 (2006.01); F25B 31/00 (2006.01); F25B 41/20 (2021.01)
CPC F25B 7/00 (2013.01) [F04B 41/06 (2013.01); F04C 2/025 (2013.01); F04C 11/001 (2013.01); F25B 31/004 (2013.01); F25B 41/20 (2021.01)] 18 Claims
OG exemplary drawing
 
1. A multi-compressor system comprising:
a plurality of compressors which are parallelly coupled, the plurality of compressors comprising at least two compressors, each compressor including a compressor shell provided with a refrigerant suction fitting, a refrigerant discharge fitting and an oil balancing connection, each oil balancing connection being fluidly connected to a low pressure volume of the respective compressor,
a common suction line and inlet connection lines each connecting the common suction line to the refrigerant suction fitting of a respective compressor,
a common discharge line and outlet connection lines each connecting the common discharge line to the refrigerant discharge fitting of a respective compressor,
a common oil balancing line and balancing connection lines each connecting the common oil balancing line to the oil balancing connection of a respective compressor, and
a plurality of spring-loaded normally-open valves each associated with a respective compressor, each spring-loaded normally-open valve being configured to occupy an open configuration in which said spring-loaded normally-open valve fluidly connects the low pressure volume of the respective compressor with the common oil balancing line and a closed configuration in which said spring-loaded normally-open valve at least partially fluidly isolates the low pressure volume of the respective compressor from the common oil balancing line, each spring-loaded normally-open valve being configured to be displaced in the closed configuration when a pressure difference between a pressure prevailing in the low pressure volume of the respective compressor and a pressure prevailing in the common oil balancing line reaches a predetermined value.