|Publication number||US3252298 A|
|Publication date||May 24, 1966|
|Filing date||Dec 2, 1964|
|Priority date||Dec 7, 1963|
|Publication number||US 3252298 A, US 3252298A, US-A-3252298, US3252298 A, US3252298A|
|Inventors||Andrews Thomas D H|
|Original Assignee||Dowty Technical Dev Ltd|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (9), Referenced by (6), Classifications (22)|
|External Links: USPTO, USPTO Assignment, Espacenet|
2 May 24, 1966 Filed Dec. 2, 1964 T. D. H. ANDREWS REFRIGERATION SYSTEMS 2 Sheets-Sheet 1 INVENTOE THOMAS M. ANDREWS MW! m ATTORNEY May 24, 1966 T. D. H. ANDREWS 3,252,298
Filed Dec. 2, 1964 REFRIGERATION SYSTEMS 2 Sheets-Sheet 2 INVENTOR THOMAS D. H. ANDREWS EA/Mm mm A-rw-oszwav United States Patent 3,252,298 REFRIGERATION SYSTEMS Thomas D. H. Andrews, Cheltenham, England, assignor to Dowty Technical Developments Limited, Cheltenharn, England, a British company Filed Dec. 2, 1964, Ser. No. 415,294 Claims priority, application Great Britain, Dec. 7, 1963, 48,409/63 6 Claims. (Cl. 62-323) This invention relates to refrigeration systems.
According to the invention there is provided a closedcircuit compressor-type refrigeration system in which the compressor is driven by a turbine, in turn powered by the exhaust discharging from an associated engine. When the refrigeration system is used in an engine-driven vehicle, the exhaust discharge which powers the turbine will be derived from the engine driving the vehicle.
The refrigeration system, which also includes a condenser, receiver and evaporator, in conventional manner, may be so arranged that a relatively large flow of refrigerant is circulated at relatively low pressure so that only ice From the delivery port 29 of the compressor 15 a pipe 30 is taken to connect with the pipe 27 at the inlet of the condenser 17, the pipe 30 including an outlet service valve 31 positioned just downstream of the port 29.
The condenser is so positioned with respect to the vehicle that cooling air can be passed across it, and the outiet side of the condenser is connected by a pipe 32 to the liquid receiver 16 which, in conventional manner, also a relatively low compression ratio across the compressor is required for the refrigeration function. In this way a turbine of relatively smallsize can be employed.
The compressor may be of centrifugal type and the refrigerant of such nature that the tip speed of the compressor rotor is maintained below sonic velocity in that refrigerant, and thus a critical gas speed in operation of the compressor is avoided.
Sealing means may be provided between the compressor and turbine, a portion of the sealing means being effective when the turbine and compressor are operating, and another portion thereof being effective when the turbine and compressor are not operating, said means being intended to prevent leakage of refrigerant from the compressor towards the turbine and to prevent exhaust leakage from the turbine towards the compressor.
One embodiment of the invention will now be particularly described, by way of example with reference to the accompanying drawings, of which,
FIGURE 1 diagrammatically shows a refrigeration system applied in a vehicle for the air conditioning of the vehicle, and,
FIGURE 2 is an enlarged cross-sectional elevation of a part of the turbine-compressor unit shown in FIG- URE 1.
Referring to FIGURE 1 of the drawings, the refrigeration system includes an evaporator 11 which is mounted in heat-exchange relation across a duct 12 which leads from the exterior of a vehicle to the interior thereof. An electrically-driven fan 13 is provided ahead of the evaporator 11.
The refrigeration system also includes in conventional manner, a condensing unit generally indicated at 14 comprising a compressor 15, a receiver 16 and a condenser 17. The compressor 15 is of non-positive displacement, centrifugal type and its rotor 18 is mounted upon a shaft 19. This shaft is arranged to be driven by a turbine 20, the rotor 21 of which is also mounted upon the shaft.
The turbine casing is of torus shape and has an exhaust inlet 22 and an exhaust outlet 23. The inlet 22 is coupled to the exhaust manifold of the internal combustion engine (not shown) which powers the vehicle.
The inlet 24 of the centrifugal compressor 15 is connected by means of a pipe 25 to the outlet side of the evaporator 11, a refrigerant inlet service valve 26 being provided in this pipe just upstream of the inlet 24. A pipe 27 is branched from the pipe 25 at a point upstream of the service valve 26 and is taken to the inlet side of vided in the pipe 27.
acts as a drier and a sight glass for the refrigerant. A pipe 33 is taken from the liquid receiver 16 through a thermostatically-operated expansion valve 34 to the inlet side of the evaporator 11. The thermostat 34a associated with the valve 34 is positioned on the outlet side of the evaporator 11 in the pipe 25.
Thus the evaporator, 11, compressor 15, receiver 16, condenser 17 and the associated pipes constitute a closed circuit.
Static and dynamic refrigerant sealing means generally indicated at 35 in FIGURE 1, are provided to the left of the compressor rotor 18 in the drawing to prevent the escape of refrigerant from the system along the shaft 19 into the turbine 20 and also to prevent leakage of gas from the turbine into the compressor.
Referring now to FIGURE 2 of the drawings, the shaft 19 is mounted for rotation in a first bearing 36 and in a second bearing (not shown). To the left in the drawing of the compressor rotor 18 and surrounding the shaft 19 is a static sleeve 37. A helical pump 38 is formed upon the shaft 19 for lubricating a first bearing 36, lubricating oil being drawn in by' the pump from an inlet passage 39 through an annulus 40 formed in the shaft. Drain oil passes from the bearing through a drain passage 41. In like manner a similar pump (not shown) is provided for lubrication of the second shaft bearing. To the right in the drawing of the annulus 40 the shaft is formed with a double-helical grooving 42 to provide a dynamic seal forming a portion of the means 35 and designed to take oil from the annulus 40 and to generate a pressure wedge at the position 43 intermediate the effective length of the grooving and around its periphery to prevent leakage of refrigerant from the compressor towards the turbine when the shaft is rotating.
Associated with the static sleeve 37 is a two-part static sealing arrangement forming another portion of the means 35. The first part of this arrangement comprises a rubber sealing diaphragm 44 which is sandwiched between casing components 45 and 46 and which is seated also upon a flanged portion 47 of the static sleeve 37. The second part of the static sealing arrangement comprises a rubber tubular member 48 having a radially-inwardly directed and tapered head portion 49 which in the static condition of the shaft 19 is an interference fit upon the external surface of thecylindrical portion of the static sleeve 37. The member 48 is carried upon a sleeve 50 secured to the compressor rotor 18 and thus when the rotor and shaft commence to rotate, the member 48 is also rotated.
In operation of the vehicle 12, the exhaust-gas-powered turbine rotor 21 drives the compressor rotor 18, heatladen refrigerant vapour being drawn in by the compressor from the evaporator 11 through the pipe 25 and refrigerant inlet service valve 26. The compressor pumps this vapour through the outlet port 29 and the outlet service valve 31 into the pipe 30, the high pressure vapour passing then into the condenser 17. Cool ing air is driven over the outside of the tubes of the condenser 17 to absorb the heat. The high pressure vapour then condenses and the refrigerant, now liquid under high pressure, passes into the receiver 16, thereafter passing through the pipe 33 and the expansion valve 34 into the evaporator 11, turing back into vapour,
in known manner, and taking heat from the air which is passing in heat-exchange relation with the evaporator 11 at it enters the interiorof the vehicle through the duct 12. The cycle continues, the difference in pressure on the two sides of the system keeping the refrigerant flowing to the evaporator 11 so that cooling of the air entering the interior of the vehicle is maintained.
The hot gas by-pass valve 28 is provided for control of the high pressure vapour permitted to pass into the condenser 17.
Suitable valve means (not shown) are incorporated in association with the duct 12 which conveys the air to the interior of the vehicle.
During operation of the system thedynamic seal 42 is operative to prevent leakage of refrigerant towards the turbine and to prevent leakage of exhaust gas from the turbine towards the compressor. During operation, however, by virtue of the mass of the head portion 49 of the static sealing member 48, the centrifugal force arising with rotation causes the head portion to be held deflected radially-outwardly away from the external surface of the static sleeve 37 so that it has no contact at all with this surface and thus is intended to suffer no wear. limits the extent of deflection of the member 48. When, however, the turbine-compressor unit is stationary and the dynamic seal is ineffective, the static sealing member 48 is no longer held deflected radially-outwardly and thus is in its interference sealing condition with respect to the external cylindrical surface of the static sleeve 37. The two parts of the static sealing arrangement then prevent leakage of the refrigerant from the refrigeration system towards the turbine, but as soon as rotation of the shaft 19 recommences for restarting of the refrigera-' tion system, the interference fit of the member 48 upon the static sleeve is quickly release.
The system is so arranged that a relatively large flow of refrigerant is circulated at relatively low pressure, the temperature of the refrigerant passing into the evaporator 11 being only cold, for example, 40 to 50 degrees Fahrenheit, rather than very cold as would be necessary where a. smaller mass flow of refrigerant was passing through the evaporator.
Dichlorodifluoromethane is preferable as refrigerant because it is of such nature that the tip speed of the compressor rotor 18 is maintained below sonic velocity .while pumping this refrigerant, and thus a critical 'gas speed from the compressor rotor is not reached in the 'operating range required of this rotor when pumping the the compressor or an electric motor drive.
It has been found in the present embodiment that 4 from threeto five horse-power is required to drive the refrigeration system and by so arranging to obtain the refrigeration system driving power from the exhaust gases otherwise going to Waste into the atmosphere, this enables a substantial proportion of this amount of horsepower to be utilised in the traction of the vehicle.
Although in the embodiment above described, the compressor rotor is of the centrifugal type, this invention is in no way limited to such, as compressors of other suitable type are used in other embodiments. Further, the invention is in no way limited to the singe stage compressor and turbine arrangement, as in other An internally-tapered cylindrical member 51 embodiments, multi-stage compressor and/ or turbine units are employed.
Further, the invention is not limited to use in vehicles as in other embodiments it is used in conjunction with stationary engine plant for cooling associated equipment or enclosures.
Again, in another embodiment of the invention, the turbine driving the compressor of the refrigeration system is also arranged to drive another compressor, itself used for supercharging the engine.
Although in the embodiment described with reference to the drawings the turbine is driven by engine exhaust gases, in another embodiment the turbine is instead driven by the exhaust flow discharging from a steam turbine.
Further, although in the embodiment described with reference to the drawings the compressor is of the nonpositive displacement type, in other embodiments the compressor is of the positive displacement type, either with or without a reduction gear in the drive to it from the turbine.
I claim as my invention:
1. A closed-circuit compressor-type refrigeration system including, in combination, a rotary compressor for circulating refrigerant within the enclosed circuit of the system, a turbine connectlble to an associated engine in a manner whereby it is driven by the exhaust gases discharging from that engine, a casing provided between said compressor and said turbine, bearing means housed within said casing, a shaft mounted in said bearing means and connecting'said turbine to said compressor thereby to drive the compressor when the turbine is operating, and seal means provided along said shaft including dynamic seal means effective only when the system is operative, and static seal means effective only when the system is inoperative, said dynamic and static seal means being arranged in series.
, 2. A refrigeration system as claimed in claim 1 wherein said compressor is of the centrifugal type.
3. A refrigeration system as claimed in claim 1, wherein said dynamic seal means is of pressurized type and comprises: a fluid pump having an outlet adjacent to said shaft; and a double-helical grooving cut in said shaft and co-operable with said casing and in communication with said fluid pump outlet.
4. A refrigeration system as claimed in claim 1, wherein said static seal means includes: a stationary tubular member; a flexible tubular member having a first end portion secured to said compressor and a second end portion disposed about said stationary tubular member to thereby be rotatable with said compressor, said second end portion of said flexible member being deformable radially-outwardly under centrifugal force and having an inwardly-directed flange engageable in fluid sealing relation with said stationary tubular memher.
5. A refrigeration system as claimed in claim 4, wherein said flexible tubular member is of rubber-like material.
6. A refrigeration system as claimed in claim 5, wherein said fluid pump is of helical form and includes helical grooving provided on said shaft, and wherein said pump outlet is in communication with said bearing means.
References Cited by the Examiner UNITED STATES PATENTS 2,608,423 8/ 1952 Wilfley 277-134 2,670,613 3/ 1954 Haltenberger 62238 2,774,219 12/ 1956 Kelley 62'243 2,781,209 2/ 1957 Jacobs 277-25 2,860,896 11/1958 Naumann 277-134 2,898,745 8/ 1959 Weisel 62243 2,936,715 5/1960 Southam 27725 3,051,497 8/1962 Wigg 27'7134 3,076,656 2/1963 Hofmann 277-134 WILLIAM. J. WYE, Primary Examiner.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2608423 *||Aug 11, 1949||Aug 26, 1952||Wilfley & Sons Inc A||Shielding device for antifriction bearings|
|US2670613 *||Aug 20, 1952||Mar 2, 1954||Jules Haltenberger||Expansion cooling|
|US2774219 *||Oct 27, 1954||Dec 18, 1956||Gen Motors Corp||Automobile refrigerating apparatus|
|US2781209 *||May 3, 1954||Feb 12, 1957||Allis Chalmers Mfg Co||Dynamic seal for a centrifugal pump|
|US2860986 *||Aug 31, 1956||Nov 18, 1958||Eastman Kodak Co||Partially acetalized polyvinyl alcohol containing active halogen|
|US2898745 *||Apr 19, 1954||Aug 11, 1959||Zenas V Weisel||Automobile air conditioning and supercharging system|
|US2936715 *||Nov 14, 1955||May 17, 1960||Thompson Ramo Wooldridge Inc||Seal assembly|
|US3051497 *||Jan 20, 1958||Aug 28, 1962||Rolls Royce||Sealing means between relatively rotating parts|
|US3076656 *||Dec 23, 1960||Feb 5, 1963||Voith Gmbh J M||Hydrodynamic seal especially for pumps, compressors and turbines|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3617151 *||Aug 18, 1969||Nov 2, 1971||Drilling Well Control Inc||Fluid flow controlling valve and system|
|US3973779 *||Jun 13, 1974||Aug 10, 1976||Firma Feodor Burgmann Dichtungswerk||Sealing arrangement|
|US4187694 *||Nov 21, 1978||Feb 12, 1980||Midolo Lawrence L||Binary working fluid air conditioning system|
|US4775817 *||Aug 5, 1987||Oct 4, 1988||U.S. Philips Corporation||Faceplate cooling system for display tube|
|US5822999 *||May 1, 1997||Oct 20, 1998||Electrolux Espana, S.A.||Refrigeration system|
|WO2012159855A1 *||May 2, 2012||Nov 29, 2012||Robert Bosch Gmbh||Vehicle coolant circuit, use of a turbo compressor, air-conditioning system and vehicle|
|U.S. Classification||62/323.1, 277/430, 415/72, 417/407, 60/597, 62/243, 62/402, 62/498, 277/426, 122/250.00R, 415/168.3, 277/553|
|International Classification||B60H1/32, F25B1/053, F25B1/04, F25B11/00|
|Cooperative Classification||F25B1/053, F25B11/00, B60H1/3223|
|European Classification||F25B11/00, F25B1/053, B60H1/32C3|