US3220210A

US3220210A - Jet refrigeration apparatus

Info

Publication number: US3220210A
Application number: US135885A
Authority: US
Inventors: Stanley J Rachfal; Stuart E Johnson; Darwin G Traver
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1961-09-05
Filing date: 1961-09-05
Publication date: 1965-11-30
Anticipated expiration: 1982-11-30

Description

30, 1965 5. J. RACHFAL ETAL 3,220,210

JET REFRIGERATION APPARATUS Filed Sept. 5, 1961 2 Sheets-Sheet 1 CONDENSING FLUID OUT RETURN FROM COOLING TO COOLING CONDENSING FLUID IN INVENTORS. STANLEY J. RACHFAL STUART E. JOHNSON DARWIN G. TRAVER ATTORNEY.

NOV. 30, 1965 s J RACHFAL ETAL 3,220,210

JET REFRIGERATION APPARATUS Filed Sept. 5, 1961 2 Sheets-Sheet 2 FIG. 3

INVENTORS. iww -Jssassw DARWIN E. TRAVER ATTORNEY.

United States Patent 3,220,210 JET REFRIGERATION APPARATUS Stanley J. Rachfal, Syracuse, Stuart E. Johnson, East Syracuse, and Darwin G. Traver, De Witt, N.Y., as-

signors to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Sept. 5, 1961, Ser. No. 135,885 11 Claims. (Cl. 62--170) This invention relates broadly to refrigeration apparatus. More particularly, this invention relates to refrigeration apparatus employing a jet refrigeration system.

A jet refrigeration system of the kind under consideration employs an ejector through which a motive fluid is passed. The ejector is designed so that the energy available in the motive fluid supplied thereto, is utilized to induce a suitable evaporator pressure which may be a partial vacuum in a closed vessel serving as an evaporator.

The evaporator is usually of the open type wherein liquid refrigerant is fed thereto and portions thereof vaporized as the ejector draws the partial vacuum therein. The vaporized refrigerant joins the flow of motive fluid and is compressed and delivered to a condenser likewise under a suitable condensing pressure which may be a partial vacuum so that condensation of the fluid delivered thereto can take place as heat transfer between the fluid and a suitable cooling medium occurs.

The condensate is collected from the condenser in a hot well and, in the case where the motive fluid and refrigerant are water and steam respectively, returned to a boiler for conversion into steam and recirculation to the ejector assembly.

This invention has for its primary object the provision of a refrigeration machine of the kind under consideration wherein a self-contained unitary structure employing a jet refrigeration system is employed for the purpose of cooling a refrigerant. This object is accomplished through a unique structural arrangement wherein the entire machine is enclosed in a compact construction.

Another object of the invention is the provision of a refrigeration apparatus employing a jet refrigeration system wherein novel means are provided for the purpose of supplying refrigerant to the evaporator section of the machine.

A still further object of the invention is the provision of an arrangement for assembling the ejector assembly within the housing or casing enclosing the operating elements of the machine in the interest of reducing noise attendant the operation of ejector type apparatus and improving ejector performance.

A still further object of the invention is the provision of a novel arrangement of ejector construction in relation to the evaporator so that certain losses inherent in the operation of an ejector are maintained at a minimum.

These and other objects of the invention will be apparent upon a consideration of theensuing specification and drawings in which:

FIGURE 1 is an end view, partly in section, of apparatus illustrating the invention wherein other operational elements of a plant incorporating the apparatus are shown schematically;

FIGURE 2 is a side view of the apparatus shown in FIGURE 1;

FIGURE 3 is a bottom plan view illustrating a nozzle detail; and

FIGURE 4 is a view in section taken along lines 44- of FIGURE 1 illustrating certain of the internal structural arrangements employed in the apparatus serving as the subject of this invention.

Referring more particularly to the drawings for an illustration of the preferred embodiment of the invention there ice is shown a self-contained refrigeration machine employing an ejector refrigeration system wherein the housing or casing consists primarily of two portions, an upstanding evaporator portion 11 and a condensing portion 12, oriented substantially normal to the direction of the shell 11. Suitable pedestal means 13 are provided to support the machine.

The evaporator portion 11 includes a substantially circular shell or body structure 14 enclosing the evaporator section and the ejector assembly. A first or upper transverse partition 15 is located at the top of the assembly and serves to support cover 16. A second or lower transverse partition 17 is secured to pedestal 13 and supports the shell body 14.

As pointed out above, one of the features of this invention is the arrangement of certain structural membersv namely, partitions and walls, to form chambers and compartments permitting a unitary self-contained refrigeration apparatus of the kind under consideration to be obtained. To this end, there is provided a central conduit 18 connected to lower partition 17 and surrounding an opening therein so as to have communication with condensing portion 12. The upper portion of the conduit 18 is connected to the partition 15 and includes lateral opening 19 extending about a portion of the periphery thereof.

Partition 15 has secured thereto arcuate wall member 20 engaging the inner surface of cover 16. Wall 20 divides the area defined by the top cover 16 and partition 15 into a first upper chamber 21 and a second upper chamber 22. Partition 15 likewise includes a plurality of circular openings 23 and a plurality of arcuate openings 24 having webs, not shown, interspersed therebetween. Surrounding a substantial part of the lower portion of conduit 18 is a Wall 25 having a configuration as shown in FIGURE 2. Wall 25 forms with conduit 18, a compartment 26. The space '27 between wall 25 and the body member 14 accommodates refrigerant in a manner to be later explained. An additional wall 28 is provided and extends upwardly from wall 25 to partition 15. Wall 28 defines in conjunction with wall 25 and the upper portion of conduit 18, compartment 30. Wall 28 likewise forms with the inner surface of shell 14, a continuation of the refrigerant accommodating zone 27 which is coextensive with chamber 21. The lateral limits of zone 27 are determined by walls 25. Communication between compartment 30 and zone 27 is maintained through openings 31 provided in the lower portion of wall 28. Compartment 30, as well as zone 27, constitutes the evaporator section of the machine. A third horizontal partition 31' is provided connecting conduit 18 with the shell 14 in the manner shown in FIGURE 1. Partition 31 defines in conjunction With partition 15, a plenum 33 and a compartment 33, each having a shape coincident with the shape of chamber 22, note FIGURE 1 and FIGURE 4. It will be obvious from a consideration of FIGURE 1 that communication between plenum 33 and conduit 18 may be accomplished through opening 19.

In apparatus of the type under consideration, it is necessary that one or more ejector assemblies be provided for the purpose of creating a partial vacuum in the evaporator section. As used hereinafter, the term ejector assembly includes nozzle 34, preferably equipped with a fluted discharge portion 34b, and a tubular member 35 spaced from the discharge of said nozzle and including a mixing section 36, a throat section 37 and a diffuser section 38. It will be obvious that Venturi-type nozzles wherein a direct connection is made to a nozzle member having the various sections incorporated in a single unitary body, present in tube 35, together with other equivalent equipment, may be employed for the purpose desired.

The fluted discharge portion of nozzle 34 increases the mixing efliciency by providing a greater surface area surrounding the nozzle exit. At the same time, noise attendant the discharge fluid at high velocity is reduced.

In the apparatus illustrated, a plurality of nozzles 34 are mounted on the upper surface of the cover 16 and project into chamber 21 in locations determined by the openings 23 serving to mount tubes 35. Thus motive fluid such as steam supplied to the nozzle under relatively high pressure is converted into a high velocity fluid stream and supplied through the tubes 35 to the condensing section. It will be apparent from a consideration of FIGURE 1 that the lower portion of tube 35 projects through partition 17 into the area accommodating the condensing means.

Under circumstances where the refrigerant is Water, and such is the case in the embodiment chosen for description herein, a conduit is provided to supply water to a chamber 39 formed by semi-circular structural member 40 secured to the outer surface of shell 14. Openings 41 in the portion of the shell confronting the member 40 permit flow of water into the shell and into a spaced defined by flow directing bafile 42. With the arrangement shown, water is fed in relatively small streams or in a film form directly into engagement with a screen 43 extending across the zone 27 in the manner illustrated in FIGURE 1. The liquid collects in the zone 27 to a level determined by the lower end of screen member 43. Vapor formed as a result of the action of the ejector mechanism flows upwardly through eliminators 45, openings 24, into chamber 21. where it joins the high. velocity motive fluid being transmitted to the condenser.v This action, known as flashing has the effect of cooling the remaining liquid refrigerant in the evaporator section. The cooled liquid refrigerant is then transmitted to a location having a requirement for the cooled liquid.

With the arrangement shown, compartment 26 serves to insulate the tubes 35 both as to sound and to thermal effect. In order to improve ejector performance a tube 44 connects jacket 44' surrounding the part of tube 35 passing through compartment 26, with zone 27. Relatively cool fluid passes upwardly, by convection, through the space defined by jacket 44, cooling the tube and causing condensation of portions of the fluid in contact with the inner surface of tube 35. This action results in a reduction in boundary layer loss with a consequent improvement. in ejector efficiency. Fluid flowing in jacket 44' is deposited in compartment 30 for eventual return to zone 27.

There is also provided a member 46for directing liquid entrained by vapor flow from zone 27 and deposited on the eliminator 45, to compartment 30. The liquid collected in the space defined by member 46 falls by gravity into compartment 30 for eventual flow into zone 27 through openings 31. It will be noted that the pressure drop through the eliminator section will cause the difference in level of liquid in compartment 30 and in zone 27 which forms a part of the evaporator.

Referring more particularly to condensing section 12, there is shown a conventional shell-and-tube unit 50 and conventional hot well 52 resting on pedestal 13. Shelland-tube unit 50 is connected to the partition 17 through Web 53 permitting indirect communication with shell 14 and welded to pedestal 13 in the manner shown in FIGURE 2. A certain degree of flexibility is involved in the web member 53 so that limited expansion under the influence of thermal stress may take place. A conventional water box is employed to supply, from a separate source, water to the tubes of the condenser in order that condensation of the fluid supplied to the condenser by tubes 35 will occur.

A particular feature of the invention resides in the creation of two separate zones in the condenser for the purpose of condensing in two stages. To this end, bulkhead 55 is provided which extends lengthwise of the condensing unit 50. Also, included is a plate member 56 4 which extends from the bulkhead 55 to the side of the shell member of the shell-and-tube unit. Plate 56 includes an opening 57 in registry with the outlet of tubes 35a, shown in FIGURE 1.

As described above, the evaporator section formed by compartment 30 and zone 27, does not extend completely around conduit 18, but only through a major portion of the circumference. Plenum 33 and upper chamber 22 constitute the remaining sector of the shell member 11 Accordingly, there is provided a second group of nozzles 34a which depend from cover 16 through upper chamber 22 and terminate in plenum 33 in registry with tubes 35a secured to transverse partition 31'. Plate 56, in addition to being connected to the shell is connected to the undersurface of partition 17 through a flexible bellows member 58 surrounding the ends of tubes 35a projecting through the partition 17.

In order to assure the maintanance of a pressure difference within condenser 50 between the zone in communication with tubes 35 and the zone in communication with tubes 35a, bulkhead is shaped to permit those tubes 35 projecting through the evaporator section to discharge into the first or low pressure zone A. The high pressure zone B is formed by the bulkhead 55, shell surface, plate 56 and spaced gussets, not shown. Thus it will be apparent that when viewed in section the shell portion of the machine may be desecribed as being in three separate parts. The first being the central passage, the second being the evaporator section and the third being the arcuate section accommodating tubes 35a which participate in the condensing action in a manner to be later described. With the arrangement described there is likewise provided a tubular member 60 depending from the zone B of the condenser in communication with tubese 35a. Condenser 50 likewise includes an opening for connection with conduits 68, leading to an ejector 70, serving purge mechanism 75 wherein non-condensibles and portions of the condensible constituents of the gaseous mixture will flow for the purpose of separating and purging the non-condensible constituents from the mixture.

In the purge mechanism there is provided a coil having communication through line 76 with a supply of condensate from hot well 52. The condensate is employed to liquefy the condensible constituents of the gas flowing from the shell-and-tube condenser 50 through line 68 and the gas flowing through line 66 in communication with ejectors and 71 serving the purge mechanism. The condensed constituents collect in tank 64 and return to the condenser via line 63'. During operation of the machine, warm liquid flowing from the purge coil through line 67 enters the condenser at connection 67. Flashing of the liquid occurs as it enters the condenser. Under certain circumstances to be hereinafter discussed, warm liquid from the purge coil will be delivered to the spray header 61 located in condenser 50. Three-way valve 69, in conjunction with line 66, permits this route to flow.

Suitable reservoir and level control valves, not shown, may be used to maintain liquid levels in the evaporator or condenser, if desired.

It will be apparent that a pressure diiference exists between the first zone of the condenser (in communication with tubes 35) and the second zone of the condenser (in communication with tubes 35a).

Considering the operation of the machine, fluid from the boiler is supplied to

nozzles

34 and 34a, as well as nozzles 70 and 71 of the purge unit. Pump 72 supplies liquid to the purge coil and three-Way valve is indexed to provide flow of fluid to condenser connection 67'. Pump 73 is energized to provide a flow of cooling medium to the condenser. Chilled water pump, not shown, supplies water to the header 39 and extracts it from the evaporator for transmission to a locale having need for chilled water.

If the machine has been opened for service or otherwise allowed to equalize with atmospheric pressure, making it necessary to remove air therefrom prior to resumption of operation, motive fluid is supplied to nozzles 70 and 71 only, and three-way valve 69 indexed to supply liquid to spray header 61 so that sensible heat transfer between the liquid and the condenser cooling medium occurs.

Through the action of the ejectors 34, a partial vacuum is formed in the evaporator section of shell body 14. The vapor created through the flashing process described is entrained with the steam and enters the ejector tubes 35 for delivery to the condensing zone in communication therewith. Water flow is circulated through the condenser tubes at such a temperature that condensation of the vapor supplied by the ejector tubes 35 occurs in the zone served by those tubes. Vapor, uncondensed after passage through the first or relatively low pressure zone, is induced by the action of ejectors 34a to flow upwardly through conduit 18 and be mixed with the motive fluid in the ejector tubes 35a. From the diffuser section 38a of tubes 35a the vapor enters the high pressure zone of condenser 50 where complete condensation takes place. Non-condensibles in the high pressure zone of the condenser are withdrawn by the action of the purge mechanism wherein the separate ejectors 70, 71, withdraw non-condensibles in the manner shown. Condensate formed in the low pressure zone of the condenser flows directly through opening 65 to the hot well 52. Condensate formed in the high pressure zone of condenser 50 flows through tube 60 into hot well 52.

As described above, the condensate collecting in hot well 52 is returned to the boiler in the manner illustrated in FIGURE 1. In the event additional water is needed for flow in the closed circuit including the evaporator section, such is available through the action of level control valve, not shown, connecting the pump 72 with the evaporator, as indicated above.

Variations of the structure described may be made without departing from the invention. For example, the ejectors may all be employed for the purpose of creating a partial vacuum. Under these circumstances the evaporator section would extend around the circumference of the circle defined by the inner surface of shell 14. Condensation would occur at a single pressure level. The partial vacuum maintained in the condenser 50 enables the condensation action described in connection with the description of the embodiments illustrated in FIGURES 1 and 2 to be accomplished. In all other respects, the operation is the same as that described in connection with the embodiment illustrated in FIGURES 1 and 2.

Control of the operation of the machine consists of terminating or activating the operation of one or more of the ejector assemblies in response to the temperature of the cooling medium entering the condenser. If the temperature of the medium rises above a predetermined value, one or more of the ejectors 34 is inactivated by terminating supply of motive fluid thereto. This is accomplished by closing valve 80 connecting the ejector nozzle to the supply line 66. Thus stable operation is assured. On the other hand, if the temperature of the condenser cooling medium drops below a predetermined value, the ejectors 34a are inactivated and the pressure within the condenser becomes substantially equal as inactive tubes 35a serve as passages for vapor uncondensed in the zone of the condenser in communication with tubes 35. Thus the entire condensing surface is available, increasing condenser efficiency.

While we have described a preferred embodiment of our invention, it will be understood the invention is not limited thereto but may be embodied within the scope of the following claims.

We claim:

1. Refrigeration apparatus comprising unitary structural means forming a housing including a condensing section and an evaporator section; said housing including a substantially vertical portion of a predetermined configuration, partition and wall means defining with the inner surface of the vertical portion the evaporation section extending about a substantial portion of the circumference of the housing, a self-contained jet refrigeration means energized solely by the fluid and disposed within said structural means, including at least one ejector assembly having a nozzle for receiving motive fluid, said noz zle being adapted to create a partial vacuum in said evaporator and induce partial vaporization of refrigerant in said evaporator, tubular means for delivering the mixture of motive fluid and vaporized refrigerant to the condenser section for liquefaction therein; means for supplying refrigerant to said evaporator section and means for withdrawing liquid refrigerant cooled as a result of the partial vaporization of refrigerant supplied to the evaporator.

2. The invention set forth in claim 1 wherein said means for supplying refrigerant to said evaporator section includes means extending about .an apertured portion of the outer surface of the vertical portion and forming therewith a header for delivering refrigerant through said apertures to the evaporator section.

3. The invention set forth in claim 2 wherein means are provided for delivering refrigerant to said evaporator section in film form.

4. The invention set forth in claim 3 wherein a screen is provided to disperse liquid refrigerant fed to the evaporator section while enabling flow of vaporous refrigerant from the evaporator section formed by the action of the nozzle of said ejector.

5. The invention set forth in claim 4 wherein eliminators are provided to form a surface for the deposit of liquid refrigerant entrained in the vapor flow to the ejector.

6. The invention set forth in claim 5 wherein means are provided for receiving liquid deposited on said eliminator and returning it to the portion of the evaporator section in which refrigerant is delivered.

7. Refrigeration apparatus comprising a vertically arranged shell construction, partition and wall means dividing the interior of said shell into a central passage and two compartmentalized sections enclosing said passage, means for supplying refrigerant to one compartment of the first of said sections, condensing means having a first zone in communication with said passage and a second zone, a first ejector assembly mounted to extend through said first section into the first zone of said condensing means so as to create in response to the flow of motive fluid therethrough a partial vacuum in the compartment and deliver gaseous refrigerant formed as a result, together with motive fluid to the first zone of said condensing means, a second ejector assembly mounted in said second section with the discharge thereof in communication with the second zone of said condensing means and the inlet thereof in communication with the first zone of said condensing means through said central passage whereby gaseous fluid in excess of the condensed in said first zone is delivered to the second zone for condensation at a higher pressure level upon the supply of motive fluid to the second ejector assembly.

8. Refrigeration apparatus comprising a closed vessel including a first substantially cylindrical vertically extending shell portion and a second portion connected therewith; a first apertured partition extending transversely of said shell portion at the upper end thereof; a first wall connecting the partition and the top of said shell portion to form first and second upper chambers; a conduit, hav- 1ng an opening extending along a portion of the periphery thereof, depending from the underside of the first partition; a second transverse partition disposed in the lower end of said shell portion, said second partition having a first opening in communication with said conduit; second wall means arranged in spaced relation to the side of said shell and surrounding a part of said conduit to form therewith a first compartment; said Wall forming with said shell a refrigerant accommodating zone; third wall means arranged in spaced relation to the side of said shell and forming, with the conduit, the first transverse partition and the first wall means, a second compartment arranged vertically above said first compartment and, an uninterrupted continuation of said refrigerant accommodating zone; a third partition arranged in spaced relation with the part of said first partition defined by the second chamber to form a plenum in communication with the peripheral opening in said conduit; a first group of ejectors each of which includes a nozzle member mounted in the top of the shell portion and extending downwardly into said first chamber and a tube having a mixing section, a throat section and a diffuser section, arranged in registry with said nozzle member and extending from an opening in said first apertured partition through. the first and second compartments through the second transverse partition and terminating in the second portion of said vessel; a second group of ejectors each of which includes a nozzle member mounted in the top of the shell and extending downwardly into the plenum and a tube having a mixing section, athroat section and a diffuser section, arranged in registry with said nozzle and extending downwardly from said first partition through said second partition and terminating in said second vessel portion; condensing means arranged in said second vessel section including a bulkhead disposed so as to divide the condensing means into a first region into communication with the first group of ejector tubes and conduit and a second region in communication with said second group of ejector tubes; and means providing a seal between said regions of said condensing means whereby relatively high pressure fluid emanating from said first group of ejector nozzles at relatively high velocity creates a partial vacuum in said refrigerant accommodating zone, evacuates portions of liquid refrigerant formed into the gaseous state and delivers said gaseous refrigerant to the first region of said condenser for liquefaction therein and relatively high pressure fluid emanating from said second group of ejector nozzles of relatively high velocity creates a partial vacuum in said first region of said condensing means, evacuates gaseous refrigerant in excess of that liquefied in said first region and delivers same to the second region of said condensing means for liquefaction therein.

9. The invention set forth in claim 8 including control means adapted to inactivate one or more of the ejectors in said first group in response to a temperature of said condenser cooling medium in excess of a predetermined value.

10. The invention set forth in claim 9 including control means operable in response to a temperature of said condensing cooling medium below a predetermined value to inactive one or more of the second group of ejectors.

11. Refrigeration apparatus comprising unitary struc tural means forming a housing including a condensing section and an evaporator section; a self-contained jet refrigeration system disposed within said structural means, including at least one ejector assembly having a nozzle for receiving motive fluid, said nozzle being adapted to create a partial vacuum in said evaporator and induce partial vaporization of refrigerant in said evaporator and tubular means for delivering the mixture of motive fluid and vaporized refrigerant to the condenser section for liquefaction therein; means for supplying refrigerant to said evaporator section, means for withdrawing liquid refrigerant cooled as a result of the partial vaporization of refrigerant supplied to the evaporator and means for introducing a portion of the liquid refrigerant to flow in heat transfer relation with at least 'a portion of said tubular means.

References Cited by the Examiner UNITED STATES PATENTS 92,622 7/1869 Mack 103278 2,105,545 1/1938 McBath 62-270 2,106,362 1/1938 Stalcup 62-270 FOREIGN PATENTS 322,796 7/ 1920 Germany.

MEYER PERLIN, Primary Examiner.

EDWARD J. MICHAEL, ROBERT A. OLEARY Examiners.

Claims

1. REFRIGERATION APPARATUS COMPRISING UNITARY STRUCTURAL MEANS FORMING A HOUSING INCLUDING A CONDENSING SECTION AND AN EVAPORATOR SECTION; SAID HOUSING INCLUDING A SUBSTANTIALLY VERTICAL PORTION OF A PREDETERMINED CONFIGURATION, PARTITION AND WALL MEANS DEFINING WITH THE INNER SURFACE OF THE VERTICAL PORTION THE EVAPORATION SECTION EXTENDING ABOUT A SUBSTANTIAL PORTION OF THE CIRCUMFERENCE OF THE HOUSING, A SELF-CONTAINED JET REFRIGERATION MEANS ENERGIZED SOLELY BY THE FLUID AND DISPOSED WITHIN SAID STRUCTURAL MEANS, INCLUDING AT LEAST ONE EJECTOR ASSEMBLY HAVING A NOZZLE FOR RECEIVING MOTIVE FLUID, SAID NOZZLE BEING ADAPTED TO CREATE A PARTIAL VACUUM IN SAID EVAPORATOR AND INDUCE PARTIAL VAPORIZATION OF REFRIGERANT IN SAID EVAPORATOR, TUBULAR MEANS FOR DELIVERING THE MIXTURE OF MOTIVE FLUID AND VAPORIZED REFRIGERANT TO THE CONDENSER SECTION FOR LIQUEFACTION THEREIN; MEANS FOR SUPPLYING REFRIGERANT TO SAID EVAPORATOR SECTION AND MEANS FOR WITHDRAWING LIQUID REFRIGERANT COOLED AS A RESULT OF THE PARTIAL VAPORIZATION OF REFRIGERANT SUPPLIED TO THE EVAPORATOR.