US2867097A - Heat pump refrigerating apparatus - Google Patents

Description

Jan. 6, 1959 D. s. JUSTICE 2,867,097

HEAT PUMP REFRIGERATING APPARATUS Filed April 7, 1955 CONDENSER INVENTOR. lg r mld SZWice,

United States Patent i HEAT PUMP REFRIGERATING APPARATUS Donald S. Justice, Washington, D. C., assignor, by mesne assignments, to The Justice Company, a corporation of the District of Columbia Application April 7, 1955, Serial No. 499,850

13 Claims. c1. 62-324) This invention relates to a heat pump, and more particularly to a heat pump which is adapted to be used to obtain a refrigeration effect, although the apparatus is not so limited and may also be reversed and used to obtain a heating effect, in a manner well known in the art.

More particularly, this invention relates to a combination of apparatus including every element of the socalled refrigeration cycle, that is to say, a condenser, an expansion valve, an evaporator, and a compressor, all arranged sequentially in a closed cycle. It is within the contemplation of this invention to provide such a refrigeration cycle with a new and improved compressor which, together with the supply apparatus fully disclosed hereinafter, presents a new and improved means for achieving a compression effect.

It is therefore an object of this invention to present a new and improved apparatus which is particularly adapted to provide the compression effect utilized in the well known refrigeration cycle.

It is a further object of this invention to provide a new and improved centrifugal compression means located between the evaporator and condenser of aconventional refrigeration cycle.

It is a further object of this invention to provide a heat pump having a centrifugal force pump interposed within the closed cycle and arranged to pressurize refrigerant in a gaseous state between columns of refrigerant in a liquid state, the liquid refrigerant being drawn from the condenser receiver or from some other source.

These and other objects and advantages of the present invention will be apparent from a consideration of the following description of a specific embodiment shown for purposes of illustration in the accompanying drawings in which: A Figure l is an elevational view, partially in section, of a heat'pump embodying the invention;

Figure 2 is a fragmentary elevational view, taken in section, illustrating a modification of the compressor shown in Figure 1;

Figure 3 is a section taken along line 3--3 of Figure 2;

Figure 4 is a fragmentary section, taken in elevation, illustrating a modified U-tube; and

Figure 5 is a fragmentary elevational view, with portions broken away to more clearly illustrate the invention, illustrating a modification of the compressor shown in Figures 1 and 2.

Referring to Figure 1, there is illustrated a conventional heat pump arrangement including a condenser discharging into a condenser receiver 12 which is, in turn, coupled by means of conduit 14 to an expansion means, herein illustrated as expansion valve 16. .The discharge side of the expansion valve 16 is connected to an evaporator 18 which is coupled by conduit 20 to a compressor which will be described in detail hereinafter. The compressor discharge line 22 completes the circuit by leading to the condenser 10.

It is within the contemplation of this invention to 2,867,097 Patented Jan. 6, 1959 utilize the well known and accepted heat pump cycle, sometimes referred to as a refrigeration cycle, in which a volatile fluid is circulated through a closed system. The cycle may be most easily described by considering the refrigerant to be stored under pressure in a receiver and then allowed to circulate through an expansion valve into an evaporator, which is usually formed as a heat exchange coil. When the valve is insulated, the expansion of the fluid refrigerant is a constant enthalpy process in which the temperature decreases as a function of the pressure drop. Assuming that the heat pump is used as a refrigerating device, the heat, at a low temperature, in an area to be cooled, passes through the walls of the evaporator and enters the liquid refrigerant. A portion of this heat is absorbed by the liquid in the form of heat of evaporation as the liquid is evaporated into a gaseous state. The gas, at a low pressure, is drawn into a pump, which is most frequently of the positive displacement variety, and compressed. The energy representing the work of compression raises both the enthalpy and the temperature of the gas within the compressor, which discharges into a condenser. Here a cooling medium is played over the walls or surfaces of the condenser to carry off a portion of the heat content of the warm refrigerant gas. A large portion of the heat carried 'off by the cooling medium represents the latent heat of the evaporation cast off as the refrigerant condenses. The condensed or liquid refrigerant then passes to the receiver and the cycle is then repeated. It is within the contemplation of this invention to utilize the foregoing procedure in the well accepted manner, except that a new and improved centrifugal pump arrangement is used in place of the conventional positive displacement compressor.

Referring to Figure 1, it will be seen that the evaporator discharge conduit 20 leads into a closed reservoir 24. Pipe 26 defines a constantly open line, hereinafter termed a priming supply conduit, between the receiver 12 and the interior of reservoir 24. As will be explained in detail hereinafter, the outlets of the priming supply conduit 26 and the evaporator discharge conduit 20 are preferably located near the top of the closed reservoir 24. A pump intake conduit 28 has its inlet 30 within the closed reservoir 24 at a position somewhat below I the open discharge end 32 of the evaporator discharge conduit 20. In a preferred embodiment, the free or open end of the pump intake conduit 28 is downwardly directed and has an opening 30 defining a horizontal plane located in spaced relation to the bottom 34 of the reservoir 24. As will be discussed in detail hereinafter, pump intake conduit 28 should be of a dimension larger than priming supply conduit 26.

The pump intake conduit 28 extends into the closed chamber 36 through a suitably sealed fitting 38. A prime mover, such as an electric motor 40, is here illustrated as disposed on the opposite side of the closed chamber 36 from the fitting 38 and has the axis of its shaft 42 extending along a line defined by the axis of conduit 28. The shaft 42, or an extension thereof, extends into the closed chamber 36 through the sealing bushing 44.

The pump intake conduit 28 extends into a closed chamber 36, as stated above, and has a rotatable coupling 46 arranged on the free end thereof. The coupling carries another conduit 48 extending from and coaxially with the free end portion of the pump intake conduit 28. The axially extending conduit 48 has a radially extending centrifuging conduit 50 aflixed thereto, or, in the alternative, the axially extending conduit 48 and the radially extending centrifuging conduit 50 may be integrally formed from a single length of pipe or tubing. The centrifuging conduit 50 is secured by any suitable means to erant and gaseous refrigerant.

the shaft 42 of prime mover 40. It will therefore be readily seen that the energization of electric motor 40 will cause the conduits 48 and 50 to rotate about the axis of axially extending conduit 48 and thatany liquid confined within centrifuging conduit 50 will be urged radially outward, by centrifugal force, through opening 54 in the free end thereof.

In a preferred embodiment, the shaft 42 has a radially extending arm 52 fixed thereon, and this arm has the centrifuging conduit 50 secured thereto by any suitable means, such as clip 53. However, it should be understood that this is merely a structural detail and that any connection between the shaft 42 and the conduits 48 and 50 which results in a rotation of centrifuging conduit 50 can be substituted therefor by anyone skilled in the art.

Operation The heat pump cycle is operated in a conventional manner with liquid refrigerant from the receiver 12 passing through expansion valve 16 into the evaporator 18 where it absorbs heat from the medium to be cooled. After the liquid refrigerant evaporates into a gaseous state, it passes through evaporator discharge conduit 20 into the reservoir 24. Inasmuch as the refrigerant fluid in the receiver 12 is constantly under pressure, there is a continuous flow of liquid refrigerant into the reservoir 24 through priming supply conduit 26.

For purposes of description, it will be assumed that the reservoir is full and that there is a column of liquid standing within the axially extending conduit 48 and the centrifuging conduit 50. Energization of the motor will serve to forcibly throw the liquid standing within conduits 48 and outward, through the open free end 54 of the conduit 50, into the interior of chamber 36. The displacement of this column of liquid within conduits 48 and 50 will form a suction which will draw refrigerant fiuid from reservoir 24 into the pump intake conduit 28. Inasmuch as the pump intake conduit 28 is larger than the priming supply conduit 26, the surface of liquid refrigerant in the reservoir will soon drop to a level below the mouth 30 of the pump intake conduit 28. As the column of liquid refrigerant, at that moment disposed in the conduits 48 and 50, is displaced by centrifugal force evolved from the rotation of the conduits, a suction or vacuum will occur in the pump intake conduit 28 and the axially extending conduit 48. This suction or vacuum will draw the refrigerant, existing in a gaseous state, which has been drawn from the evaporator 18 into reservoir 24 through the evaporator discharge conduit 20, into the pump intake conduit 28. As the priming conduit 26 is continuously discharging liquid refrigerant from the receiver 12, the surface of the liquid refrigerant within the reservoir 24 will soon rise to a level above the mouth 30 of the' pump intake conduit 28 so that the vacuum or suction within the pump intake conduit 28 and the axially extending conduit 48 will draw in a fresh charge of liquid refrigerant. This new charge of liquid refrigerant will pass down the axially extending conduit 48 into the centrifuging conduit 50 and will be thrown radially outward from the free end thereof by centrifugal force, as discussed hereinafter.

It will therefore be understood that this operative arrangement of the apparatus will result in the pump intake conduit 28 drawing in alternate charges of liquid refrig- The exact volumetric relation between these two charges will depend entirely upon the dimensioning of the respective elements and upon the rate of flow of the liquid refrigerant in the priming supply conduit 26. It is within the contemplation of this invention that, in operation, the axially extending conduit 48 and the centrifuging conduit 50 will contain several alternate charges of liquid refrigerant and gaseous refrigerant at a given moment, and that the level of the liquid refrigerant in the reservoir 24 will always be quite close to mouth 30.

It will therefore be understood that both the liquid and the gaseous charges of refrigerant emitting from the free end 54 of the centrifuging conduit 50 will be under the same high pressure and that the interior of the sealed chamber 36 will be occupied by a mixture of gaseous refrigerant and liquid refrigerant under identical internal pressures. The liquid refrigerant, together with the gaseous refrigerant, will flow through compressor discharge conduit 22 to the condenser 10 where condensation of the gaseous refrigerant will occur in the normal manner.

It is within the contemplation of this invention that a cooling medium may be played over the exterior surfaces of the sealer container 36 so that its Walls are, at least in the operative sense, a portion of the system condenser.

It is also within the contemplation of this invention that the priming supply conduit 26 may draw the liquid refrigerant from the condenser 10 rather than from the receiver 12, or it may draw the refrigerant from some other equivalent source.

It will now be understood that when the compressor is stopped, and the system is not operating, the liquid in conduits 48 and 50 will have a tendency to drain through opening 54 into the chamber 36. In due course, enough liquid from the condenser 10 and receiver 12 will pass through conduit 26, reservoir 25 and pump intake conduit 28 and will fill the chamber 36 to a point where the centrifugal conduit 50 is again occupied by fluid refrigerant. When it is desired to start the operation, the motor 40 is energized and the rotation of the centrifuging conduit 50 will hurl the liquid therein forcibly out of the open end 54, thus creating a vacuum (or at least a reduction in pressure) in pump intake conduit 28 whereby other liquid from the reservoir 24 will be drawn through to the centrifuging system. At this point the system begins to operate in the manner discussed above.

Referring more particularly to Figures 2, 3, and 4, wherein there is illustrated a modification of the invention, it will be seen that the centrifuging conduit is formed with a slight curve bending in the direction opposite to the direction of rotation. The free end 102 of the centrifuging conduit 100 opens into the lumen of an annular ring 104 which is concentric with the axially extending conduit 48 and the motor shaft 42. The annular ring 104 is secured to shaft 42 by spider 106. When the centrifuging conduit 100, together with the ring 104, is rotated by the energization of the motor 40 (Figure l), the liquid refrigerant 107 emitting from the free end 102 of the centrifuging conduit 100 will centrifugally stand against the outermost portion 108 of the interior surface of the annular ring (Figure 2). For convenience, this portion 108 of the ring 104 will be termed the inner surface of the outer peripheral wall. While the charges of liquid refrigerant will lay up or stand centrifugally, as at 107, against the inner surface 108 of the outer peripheral wall of the ring 104, the gaseous refrigerant, which has a lesser density, will collect in the remaining portion of the lumen of the ring.

The ring 104 may be provided with a radial discharge means formed by a U-tube, generally indicated at 110, having the open end 112 of one leg disposed within the lumen of the ring and facing the inner surface 108 of the outer peripheral wall. The other leg extends radially of the ring and has its free end 114 opening to the interior of chamber 36 outside of the lumen of the ring 104. The U-tube is preferably located in such a manner that the base 116 is within the lumen of the ring 104, or is located outwardly of the circle defined by the inner surface 118 of the inner peripheral wall.

When the centrifugal pump is equipped with the annular ring 104 and operated in the manner discussed hereinabove, an increasing portion of the lumen of the ring 104 will become filled with liquid refrigerant which will stand against the inner surface 108 of the outer peripheral wall. That is to say, the successive charges of liquid refrigerant will build up on the inner surface of the outer peripheral wall and the successive charges of gaseous refrigerant will fill, at a constantly increasing pressure, the remaining portions of the lumen of the ring 104.

When the liquid refrigerant has built up to a point Where its surface, which will be substantially vertical, is in line with the base portion of the U-tube 110, that is, to phantom line 111, the liquid will begin to flow through the month 112 of the first leg inwardly to the base 116 and then outwardly through mouth 114 of the second leg. Once this fiow has been established, there will be a siphon effect created which will serve to drain the ring 104 until the surface of the liquid refrigerant recedes outwardly to the mouth 112 of the first leg. At this moment, the pressurized refrigerant gas confined in the ring 104 will enter the mouth 112 of the U-tube 110 and will blow out through open end 114 into the chamber 36. Inasmuch as this siphoning efiect will occur periodically as the lumen of the ring fills with liquid, the interior of the chamber 36 will, once the cycle of operation has been established, be constantly filled with a mixture of gaseous and liquid refrigerant under a high pressure.

While the annular ring discharge means discussed immediately hereinabove has been described as having the base 116 of the U-tube 110 located at a position outward of the inner surface 118 of the inner peripheral wall of the ring, it is .also within the contemplation of this invention that the first leg ofthe U-tube 110' may be elongated inwardly so that the base 116' of the U-tube 110 is substantially inward of the inner surface 118 of the inner peripheral wall. In such a case, the pressure that will be built up within the lumen of annular ring 104 by the compressed gas, the gas being pressurized by the continuing charges of liquid, will be somewhat greater than that created by the hereinabove mentioned construction. Such an elongated U-tube is illustrated in Figure 4.

It is also within the contemplation of this invention to supplement the pressure created in any of the modifications discussed hereinabove by adding a positive displacement pump apparatus within the pump intake conduit 28. In the exemplary illustration of Figure 5, rotating portion 46' of rotatable coupling 46 has a mandrel 200 fixed thereto by spider 202. The mandrel extends upwardly into the lumen of the stationary pump intake conduit 28 and has a helical thread 204 formed thereon to sweep the interior walls of conduit 28. In other words, the mandrel 202 forms a worm-type pump which gives the non-compressible liquid refrigerant an initial boost in pressure. Such a preliminary or boosting pump would in no way affect the operation of the centrifugal pumping means which has been fully described hereinabove.

Having described only a typical and preferred embodiment and application of .my invention, I do not wish to be limited or restricted to specific details set forth herein but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and falling within the scope of the following claims:

I claim:

1. A heat pump comprising the combination of an evaporator, a condenser, a refrigerant receiver, an expansion means coupled between said condenser and said evaporator, a centrifugal pump means, means for supplying alternate charges of fluid refrigerant and gaseous refrigerant to said pump means including a reservoir coupled to the discharge end of the evaporator, a downwardly extending pump intake conduit disposed in saidreservoir having its free end in spaced relation to the bottom thereof, said centrifugal pump means coupled to said pump intake conduit and arranged to discharge refrigerant to said condenser, a priming conduit extending between said receiver and said reservoir and having a flow capacity smaller than the flow capacity of said pump intake conduit, whereby said centrifugal pump means creates a suction in said pump intake conduit and said pump intake conduit draws in alternate charges of gaseoiis refrigerant and liquid refrigerant.

2. The combination defined in claim 1 in which said centrifugal pump means comprises an axially extending conduit rotatably coupled with said pump intake conduit, a centrifuging conduit coupled to the free end ofand extending substantially radially from said axially extending conduit, and a sealed chamber enclosing said conduits.

3. The combination defined in claim 1 in which said centrifugal pump means comprises an axially extending conduit rotatably coupled to said pump intake, and a hollow annular ring concentric with said axially extending conduit and fixed relative thereto, a centrifuging conduit coupled to the free end of said axially extending conduit and extending into the lumen of said ring, and means for periodically voiding said ring when the latter is rotating and becomes, at least partially, filled with refrigerant.

4. The combination defined in claim 1 in which said centrifugal pump means comprises an axially extending conduit rotatably coupled to said pump intake, a hollow annular ring concentric with said axially extending conduit, a centrifuging conduit coupled to the free end of and extending substantially radially from said axially extending conduit and extending through the inner peripheral wall of said ring to a position adjacent the inner surface-of the outer peripheral wall of said ring, a ring discharge conduit extending radially from said ring, and a sealed chamber enclosing said conduits and said ring.

5. The combination defined in claim 4 in which said annular ring discharge conduit comprises a U-tube having two legs, the free end of one leg being disposed adjacent the inner surface of the outer peripheral Wall of said annular ring, the other leg extending out of said ring and radiallythereof, whereby said annular ring will act as a trap to retain liquid refrigerant centrifugally standing against the inner surface of the outer peripheral wall of said ring, said discharge conduit being arranged to act as a siphon to periodically remove such liquid when the amount accumulated within said ring reaches the base of said U-tube.

6. In the combination defined in claim 5, a moving worm positive displacement booster pump engaged with said axially extending conduit to obtain rotation movement therefrom to raise the pressure of refrigerant passing through the said conduit.

7. A heat pump comprising the combination of an evaporator, a condenser, a refrigerant receiver means, an expansion means coupled between said condenser and said evaporator, a centrifugal pump means arranged to discharge refrigerant to said condenser, means for alternately supplying said centrifugal pump means with a charge of liquid refrigerant from said receiver means and a charge of gaseous refrigerant from said evaporator, said centrifugal pump means comprising an axially extending conduit rotatably coupled with said supplying means, a centrifuging conduit coupled to the free end of and extending substantially radially from said axially extending conduit, and a sealed chamber enclosing said conduits.

8. In the combination defined in claim -7, a hollow annular ring concentric with said axially extending conduit and fixed relative thereto, said centrifuging conduit extending into the lumen of said ring, and means for periodically voiding said ring when the latter is rotating and becomes partially filled with refrigerant.

9. In the combination defined in claim 7, a hollow annular ring concentric with said axially extending conduit and fixed relative thereto, said centrifuging conduit extending into the lumen of said ring, a ring discharge conduit comprising a U-tube having two legs, the free end of one leg being disposed adjacent the inner surface of the outer peripheral wall of said ring, and the other leg extending out of said'ring and radially therefrom, whereby said discharge conduit will act as a trap to retain liquid refrigerant centrifugally standing against the inner surface of the outer peripheral wall of said ring, said discharge conduit being arranged to act as a siphon to periodically remove such liquid when the amount accumulated within said ring reaches the base of said U- tube.

10. In the combination defined in claim 7, a moving worm positive displacement booster pump engaged with said axially extending conduit to obtain rotation movement therefrom to raise the pressure of refrigerant passing through the said conduit, said booster pump comprising a worm element fixed to said axially extending conduit and extending away therefrom into a portion of said supply means, said portion of said supply means being fixed against rotation.

11. In the combination defined in claim 8, a moving worm positive displacement booster pump engaged with said axially extending conduit to obtain rotation movement therefrom to raise the pressure of refrigerant passing through the said conduit, said booster pump comprising a Worm element fixed to said axially extending conduit and extending away therefrom into a portion of said supply means, said portion of said supply means being fixed against rotation.

12. In the combination defined in claim 9, a moving worm positive displacement booster pump engaged with said axially extending conduit to obtain rotation movement therefrom to raise the pressure of refrigerant passing through the said conduit, said booster pump comprising a worm element fixed to said axially extending conduit and extending away therefrom into a portion of 8 said supply means, said portion of said supply means being fixed against rotation.

13. A heat pump comprising the combination of an evaporator, a condenser, a refrigerant receiver, an expansion means coupled between said condenser and said evaporator, a centrifugal pump means arranged to discharge refrigerant to said condenser, means for alternately supplying said centrifugal pump with liquid refrigerant from said receiver and gaseous refrigerant from said evaporator, said centrifugal pump means comprising a prime mover, an axially extending conduit rotatably coupled to said supply means and mechanically engaged with said prime mover for rotation upon its axis, a hollow annular ring concentric with said axially extending conduit, a centrifuging conduit coupled to the free end of and extending substantially radially from said axially extending conduit into the lumen of said annular ring, means for periodically voiding the lumen'of the ring and discharging the refrigerant radially therefrom when the liquid refrigerant at least partially fills the lumen of said ring, a sealed chamber enclosing said conduits and said ring to retain the pressure created by the rotation of said centrifuging conduit.

References Cited in the file of this patent UNITED STATES PATENTS 1,195,269 Ross Aug. 22, 1916 1,375,836 Fisher Apr. 26, 1921 1,836,318 Gay Dec. 15, 1931 2,488,157 Bassano Nov. 15, 1949

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