US2963886A - Lubricant cooling system - Google Patents

Description

Dec. 13, 1960 E. P. PALMATIER LUBRICANT COOLING SYSTEM Filed Jan. 2, 1958 INVENTOR.

EVERETT P. PALMATIER BY ad! Lunnrcarrr CGOLING SYSTEM Everett P. Paimatier, Sovay, N.Y., assignor to Carrier (Iorporation, Syracuse, N.Y., a corporation of Delaware Filed Jan. 2, 1958, Ser. No. 706,630

1 Claim. (Cl. 62468) This invention relates broadly to refrigeration systems. More particularly this invention pertains to an arrangement for efliciently cooling lubricant used to lubricate the various moving parts of the systems such as a compressor.

As is necessary in any equipment that requires lubrication, cooling of the medium utilized as a lubricant is necessary. Heretofore it has been suggested that the lubricant employed in refrigeration systems having a reciprocating or centrifugal compressor as a component thereof, be cooled by inserting a heat transfer coil within the sump or crank case of the compressor. Under those circumstances where the supply of lubricant to the individual elements of the system requiring lubrication is under the influence of either an internally or an externally operated pump, I have found that the cooling of the lubricant can be effected efliciently and rapidly by routing a portion of the lubricant supply line over a portion of the evaporator so that a heat transfer action, resulting in a cooling of the lubricant, will occur.

The chief object of this invention is the provision of an economical and efficient lubrication cooling system for the lubricant used in a refrigeration system to lubricate those parts of the system requiring lubrication.

Another object of the invention involves utilizing a portion of the evaporator that normally contributes little to the overall evaporator performance for the purpose of cooling the lubricant in the lubrication system.

Other objects and features of the invention will be apparent upon a consideration of the ensuing specification and drawing wherein the figure is a diagrammatic representation of a refrigeration system, the lubrication circuit of which is cooled by virtue of a heat transfer action between the lubricant and a portion of the refrigerant in the evaporator.

Referring to the figure compressor normally forwards hot gaseous refrigerant through the line 11 to condenser 12. Liquefaction of the refrigerant in the condenser occurs by virtue of a heat transfer action between a medium passing over the outer surface of the condenser and the refrigerant within the condenser. Liquified refrigerant flows from the condenser through expansion valve 13 into evaporator 14 where it is converted to the vapor phase as air or any other medium flowing over the evaporator gives up its heat to the refrigerant. 'Ihe vaporous refrigerant then continues through suction line 15 to the compressor 10 to complete the circuit.

Lubrication of the moving parts of the compressor is provided by a pump 20 having communication with the crankcase of the compressor. Lubricant flowing through the suction line of the pump is discharged through line 21 having a portion 22 in heat transfer relation with the return bends of the evaporator 14. Preferably the evaporator consists of a continuous tubular member comprising a plurality of spaced straight portions inter-connected at their ends by arcuate tubular members called return bends. The return bends on a normal evaporator coil of the type described are disposed outside of tube sheets which in effect support the continuous tubular member defined by the vertically spaced tube portions. In other words any extended surface is normally placed on that portion of the coil in which the parallel runs are located. This invention contemplates utilizing the prime surface of the return bends to effect a heat transfer action between the refrigerant flowing in the return bends and the lubricant flowing in the portion 22 of the line 21. This action serves to prevent sweating of the return bends. The cooled lubricant after it leaves that portion of line 21 in heat transfer relation with the evaporator return bends is forwarded under the action of the pump to the parts of the compressor requiring lubrication. In the interest of clarity, the details of the part of the lubrication circuit disposed within the compressor have been deleted. However, it will be appreciated that the usual and normal reciprocating compressor is contemplated.

It will thus be apparent that a simple and effective means for cooling lubricant flowing Within the lubrication system of equipment associated with a refrigeration machine has been provided, without adding a separate component to the system and without requiring the piping of refrigerant to an oil cooler.

While I have described a preferred embodiment of the invention ti will be understood that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claim.

I claim:

In a refrigeration system including a compressor, a lubrication system for the compressor, a condenser, refrigerant expansion means, and an evaporator comprising tubular means having substantially parallel portions interconnected by end portions to form a path of flow for the refrigerant, means for cooling the lubricant including a line, forming a part of the lubrication supply circuit, having a portion in heat transfer relation with the end portions of the evaporator.

References Cited in the file of this patent UNITED STATES PATENTS Re. 24,192 Jarlais Aug. 7, 1956 1,550,856 Whitehead Aug. 26, 1925 2,684,579 Hieatt et al July 27, 1954 FOREIGN PATENTS 405,207 Great Britain Feb. 1, 1934 426,692 Great Britain Apr. 8, 1935

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