US 8,109,116 B2Granted

Dual compressor air conditioning system with oil level regulation

AssigneeMitsubishi Electric Corporation

InventorsShin Sekiya, Masayuki Kakuda, Toshihide Koda, Masahiro Sugihara

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Abstract

A refrigeration air conditioner includes a first equalizer pipe connecting a bottom portion of a first hermetic vessel, which contains a main compression mechanism and lubricating oil, to a bottom portion of a second hermetic vessel, which contains an expansion mechanism, a sub-compression mechanism, and lubricating oil. A second equalizer pipe connects a side of the second hermetic vessel at a position higher than a minimum oil level to a suction side of the main compression mechanism. The space within the second hermetic vessel is isolated from the expansion mechanism and the sub-compression mechanism, and the pressure within the second hermetic vessel is not dependent upon the pressure within the expansion mechanism and the pressure within the sub-compression mechanism.

Claims11

Dependent claims

A refrigeration air conditioner comprising:

a main compression mechanism for compressing a refrigerant;
a gas cooler for cooling the refrigerant compressed;
an expansion mechanism for expanding the refrigerant flowing from said gas cooler to recover power;
a sub-compression mechanism disposed on a discharge side or a suction side of said main compression mechanism for compressing the refrigerant using the power recovered by said expansion mechanism;
an evaporator for evaporating the refrigerant expanded at said expansion mechanism;
a first hermetic vessel containing said main compression mechanism and lubricant oil;
a second hermetic vessel containing said expansion mechanism, said sub-compression mechanism, and lubricant oil;
a first equalizer pipe connecting a bottom portion of said first hermetic vessel, at a position lower than a minimum oil level of said first hermetic vessel, to a bottom portion of said second hermetic vessel, at a position lower than a minimum oil level of said second hermetic vessel;
a second equalizer pipe connecting a side of said second hermetic vessel, at a position higher than the minimum oil level of said second hermetic vessel, to a suction side of said main compression mechanism, wherein
a space within said second hermetic vessel is isolated from said expansion mechanism and said sub-compression mechanism, and
pressure within said second hermetic vessel is independent of pressure within said expansion mechanism and pressure within said sub-compression mechanism.

8 more elements

A refrigeration air conditioner comprising:

a main compression mechanism for compressing a refrigerant;
a gas cooler for cooling the refrigerant compressed;
an expansion mechanism for expanding the refrigerant flowing from said gas cooler to recover power;
a sub-compression mechanism disposed on a discharge side of said main compression mechanism for compressing the refrigerant using the power recovered by said expansion mechanism;
an evaporator for evaporating the refrigerant expanded at said expansion mechanism;
a first hermetic vessel containing said main compression mechanism and lubricant oil;
a second hermetic vessel containing said expansion mechanism, said sub-compression mechanism, and lubricant oil;
a main compressor suction pipe connecting the first hermetic vessel to an outlet side of the evaporator;
a first equalizer pipe connecting a bottom portion of said first hermetic vessel, at a position lower than a minimum oil level of said first hermetic vessel, to a bottom portion of said second hermetic vessel, at a position lower than a minimum oil level of said second hermetic vessel;
a second equalizer pipe connecting a side of said second hermetic vessel, at a position higher than the minimum oil level of said second hermetic vessel, to said main compression suction pipe;
a first pipe connecting a discharge side of said main compression mechanism to a suction side of said sub-compression mechanism;
a second pipe connecting a discharge side of said sub-compression mechanism to an inlet side of said gas cooler;
a third pipe connecting an outlet side of said gas cooler to a suction side of said expansion mechanism;
and
a fourth pipe connecting an outlet side of said expansion mechanism to an inlet side of said evaporator, wherein
a space within said second hermetic vessel is isolated from said expansion mechanism and said sub-compression mechanism, and
pressure within said second hermetic vessel is independent of pressure within said expansion mechanism and pressure within said sub-compression mechanism.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/912,903Filed 24 May 2006
Priority: JP 2005-24589226 Aug 2005
Published: US 2009/0064709 A112 Mar 2009
Granted: 7 Feb 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

F25B 31/004
Lubrication: oil recirculating arrangements
F01C 1/0223
Where only one member is moving: with symmetrical double wraps
F01C 11/004
Of similar working principle: and of complementary function, e.g. internal combustion engine with supercharger
F01C 21/045
Lubrication: control systems for the circulation of the lubricant