EP1153251B1 - Improvements in multiple zone refrigeration - Google Patents

Abstract

The invention is embodied in a refrigeration unit (R) adapted for use in combination with plural associated refrigerated fixtures (33a, 33b, 33c) in a commercial store, each fixture having a product zone and heat transfer cooling means (29) for the refrigeration thereof and which refrigeration unit comprises housing means (55, 57) with a mounting profile constructed to be accommodated substantially within the footprint area of one of said associated fixtures and arranged to support selective refrigeration components of a closed refrigeration circuit for supplying the refrigeration requirements of all associated fixtures, and which components include plural vapor phase compressor means (21) and a closely coupled coolant loop connected with the heat transfer cooling means.

Description

FIELD OF INVENTION

This invention relates generally to the commercialrefrigeration art, and particularly to a refrigeration unitwhich is used to refrigerate a plurality of cooling zones.

BACKGROUND OF INVENTION

A modular commercial refrigeration unit constructedand arranged for placement in strategic proximity to pluralassociated product cooling zones is known, and is disclosedin US 5,440,894 commonly owned by HUSSMANN CORPORATION, thecontent of which is incorporated herein by reference. Thisprior art document discloses a supermarket or other foodstore refrigeration system including a refrigeration unitand a refrigeration network comprising a plurality of suchunits. The unit disclosed in US 5,440,894is intended for use in coolingthe zones of plural fixtures within a shopping arena(including the food merchandising and display area and thefood storage and preparation area) of a food store.

The known refrigeration unit comprises a condensing unitrack configured to accommodate the maximum refrigerationloads of the associated zones and being constructed tosupport the components of a closed refrigeration circuitincluding a plurality of multiplexed compressor means andassociated high side and low side refrigerant delivery andsuction means extending from the rack and being operativelyconnected to evaporator means constructed and arranged forcooling the associates zones, and which unit also hascondenser means with a cooling source remote from thecondensing unit rack but operatively constructed and arranged to provide a heat exchange relationship forproviding optimum condensing and efficiency of saidevaporator means in cooling the associated zones.

Another modular commercial refrigeration unitconstructed and arranged for strategic placement nearplural associated product cooling zones is known, and isdisclosed in US 5,743,102, commonly owned by HUSSMANNCORPORATION.This prior art document discloses food storerefrigeration including a refrigeration unit and coolingsystem. The unit disclosed in US 5,743,102is intended for cooling theproduct zones of plural display and storage merchandisersand fixtures. The unit comprises a condensing unit rackconfigured to accommodate the maximum refrigeration loadsof associated fixture zones and being constructed tosupport components of a closed refrigeration circuit havingmultiplexed compressors and evaporator means withassociated high side and low side refrigerant delivery andsuction means operatively connected to the evaporatormeans, and which unit also includes condenser meansoperatively connected between the compressor and evaporatormeans as a component of the refrigeration circuit; and theunit also being constructed to support components of acoolant fluid system having heat transfer means associatedwith the evaporator means and pumping means for circulatinga coolant through the heat transfer means in a closedcoolant loop to cooling coils for the associated fixtures.

An important objective of the units disclosed in US5,440,894 and US 543,102 was to seek to minimize the amountof refrigerant required in the food store refrigerationnetwork.

A further object of the units disclosed in US5,440,894 and US 5,743,102 was to obviate the need forproviding a dedicated remote plant/machine room therebyreleasing valuable floor space within a supermarket or thelike.

It has been found in practice that some merchantsremain reluctant to position the prior artunits anywhere on the sales floor of a store,thereby losing many of the refrigeration benefits whichmight be obtained.

It is an object of at least one aspect of the presentinvention to seek to address one or more of the perceivedproblems of the units disclosed in US 5,440,894 and US5,743,102.

It is a further object of the present invention toprovide a unit which, in use, effectively does not occupyany floor space.

It is yet a further object of at least one aspect ofthe present invention to seek to address the objects of theunits disclosed in US 5,440,894 and US 5,743,102.

Further objects and advantages of the unit of thepresent invention will become more apparent from thedescription provided hereafter.

Some of these various advantages provided by presentlypreferred embodiments of the present invention are:

low noise and vibration levels;

provision of two or more compressors so as to providecapacity control and back-up security;

relatively short coupled pipework thereby seeking toreduce capital and running costs and installation time;

relatively simple refrigeration circuitry;

reduced refrigerant charge and cost, as well assmaller refrigerant gas loss in an event of leakage;

flexibility for future retrofits;

heat reclaim from fluid loops providing anadvantageous energy use and improved efficiency of therefrigeration system/network;

provision of a low profile for unobtrusive mountingon top of a cooling zone fixture.

US 4,895,001 (JONDAHL) discloses an expandablerefrigeration system for use in dispensing products to thepublic, the system including a base unit with a productcontaining chamber, a refrigeration system in the base unitand having a compressor and condenser portion and a fan formoving ambient air past the condenser, an evaporatorcabinet supported adjacent the refrigeration system havingan evaporator therein, which is connected to the compressorand condenser of the refrigeration system and a fan formoving air past the evaporator whereby the air is coated,openings through which cooled air from the evaporator isconducted into the base unit product containing chamber, aslave unit having a product containing chamber contiguouswith the base unit, first and second ducts communicatingthe interior of the base unit product containing chamberwith the slave unit product containing chamber so thatcooled air circulated in the base unit is also circulatedin the slave unit allowing the addition of increasedproduct containing space without an additionalrefrigeration system.

US 4,995,243 (WARD) discloses a refrigeration unitcomposed of a drop-in package to be accommodated within anaperture in the top of a cabinet, and comprising a pluginsertable neatly into the aperture and mounting refrigeration components on top and an evaporator togetherwith an air impeller in an underside compartment, abutmentmeans on the plug to limit intrusion of the plug to aposition substantially flush with the ceiling of thecabinet, and air ducts directing air flow from the airimpeller in a path adjacent the ceiling due to a sweepingcurvature of a wall of each air duct which influences thepath of air flow in compliance with the "Coanda" effect.

US 3,180,109 (KIMMEL) discloses a refrigerateddisplay case and area heater comprising a display case,means for refrigerating said display case, saidrefrigerating means including a refrigerant condenserlocated at a position remote from said display case, meansfor passing water in heat exchanging relation with saidrefrigerant condenser so as to cool said condenser and heatthe water, heat exchange means receiving water heated bythe refrigerant condenser, a blower for forcing air overthe latter heat exchange means, and duct means fordirecting heated air received from said blower and latterheat exchange means to said display case, the duct meansforming a part of the display case and having an outletopening through which heated air may be discharged into anarea adjacent said refrigerated display case.

US 5,065,591 (SHAW) discloses a refrigeration systemincluding a rack or bank of compressors located in paralleland feeding a common condenser. Liquid refrigerant from thecondenser is supplied to a plurality of evaporators locatedin parallel and feeding a common suction manifold. Thesuction manifold is connected to the compressors andcontains a valve for selectively isolating one or morecompressors and evaporators whereby the isolated compressoracts as a satellite compressor and the isolated evaporators are operated at a lower temperature than the otherevaporators.

SUMMARY OF INVENTION

According to a first aspect of the present inventionthere is provided a refrigeration unit in combination withplural closely adjacent associated refrigerated fixtures suitable for ina commercial store, each of said fixtures having a productzone and a heat transfer cooling coil for the refrigerationthereof, CHARACTERISED IN THAT said refrigeration unitcomprises a housing with a fixture mounting profileconstructed to be accommodated within a footprint area ofat least one of said associated fixtures and being arrangedto support selected refrigeration components of a closedrefrigeration circuit for supplying the refrigerationrequirements of all associated fixtures, which saidcomponents include plural vapor phase compressors and aclosely coupled cooling loop connected with the heattransfer cooling coils of all associated fixtures.

Herein the term "footprint" of an associatedrefrigerated fixture is understood to mean the floor spacearea occupied by the refrigerated fixture as viewed fromabove (or below)

The unit may be used in a food store, such as asupermarket or the like.

A fixture may comprise a merchandising, storage orprocessing cabinet or fixture.

One or more of such merchandising cabinets may beprovided in-line, back to back, or in closely adjacentproximity.

The unit is preferably provided over or on top of onefixture.

Preferable features of the refrigeration unit incombination with plural closely adjacent associatedrefrigerated fixtures according to the first aspect of thepresent invention are recited in claims 2 to 22, appendedhereto.

According to a second aspect of the present inventionthere is provided the combination of at least twodiscrete, closely adjacent associated refrigerated fixturessuitable for use in an commercial store, each of which fixtures has acabinet with a top wall surface and having a product zoneand a heat transfer cooling coil for the refrigeration ofits product zone with a refrigeration unitcharacterised inthat the refrigeration unit comprises a housing with amounting profile constructed so as to be accommodatedwithin the top wall footprint area of one of saidrefrigerated fixtures and being arranged to supportselected refrigeration components of a closed refrigerationcircuit including plural vapor phase scroll compressorsoptionally having different capacities, and a closelycoupled cooling loop connected to supply the refrigerationrequirements of the heat transfer cooling coils of allassociated refrigerated fixtures.

Preferable features of the combination according tothe second aspect of the present invention are recited inclaims 24 to 33 appended hereto.

The plural compressors preferably comprise two or morecompressors that are multiplexed by being connected inparallel in the refrigeration circuits, and preferably thecompressors are of a horizontal scroll type. This providesthe advantage of a "low-profile" unit which may beprovidentially or strategically placed on top of oneproduct fixture while being constructed and arranged to refrigerate the plural cooling zones of at least twoclosely associated fixtures.

Alternatively,one or more of the compressors may be of a vertical scrolltype.

According to a preferred embodiment of the presentinvention, a modular low-profile refrigeration unit isconfigured to accommodate the maximum aggregaterefrigeration loads of at least two product cooling zonesprovided in a food store area, the unit comprising closedrefrigeration circuit components including a plurality ofmultiplexed compressor means and associated refrigeranthigh side delivery means and low side suction means, theunit being constructed and arranged for placement, in use,in strategic proximity to the product cooling zones, andbeing operatively connected to evaporator means for therespective zones, and the refrigeration circuit alsoincluding condenser means.

The condenser means may include a condenser within theunit, which in use may be operatively associated with aremote cooling source so as to provide a heat exchangerelationship with the condenser.

The remote cooling source may be a fluid coolingsource, such as a cooling tower or a ground source watersupply, or a dedicated normal temperature refrigerationsystem, a chiller system or recirculating water source or acombination of such alternate fluid cooling sources toassure the condenser means of a continuous supply of liquidcoolant at a substantially constant temperature.

Alternatively, the condenser means may comprise acondenser remote from the unit and having a heat exchange cooling source, such as being air cooled.

Whether the condenser is located on board therefrigeration unitper se or remote therefrom, thecondensing means may include heat reclaim which may bedirect or as a heat pump.

According to a further aspect of the presentinvention there is also provided a refrigeration system,which includes at least one refrigeration unit according tothe first aspect of the present invention.

The refrigeration unit of the system will cool thecooling zones of at least two fixtures, and the unit issubstantially contained within the footprint size of one ofthe fixtures.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now bedescribed, by way of example only, and with reference tothe accompanying drawings, which are:

Figure 1

a front perspective view of a low-profilerefrigeration unit according to a firstembodiment of the present invention;

Figure 2

a plan view of the unit of Figure 1;

Figure 3

a view from one end of the unit of Figure 1;

Figure 4

a front perspective view of a refrigerationsystem comprising a multiple zoned orcombination merchandiser including the unitof Figure 1;

Figure 5

a plan view of the refrigeration system ofFigure 4;

Figure 6

a plan view of the unit of Figure 1 with acover of the unit removed;

Figure 7

a side elevational view of the unit ofFigure 1 with the cover removed;

Figure 8

a schematic diagram of one embodiment ofrefrigeration circuitry for a systemembodying the invention;

Figure 9

an alternate schematic diagram of therefrigeration system of Figure 8;

Figure 10

a partial schematic diagram showing amodification of the refrigeration system ofFigures 8 and 9; 20 and

Figure 11

a schematic diagram of another embodiment ofa refrigeration circuit.

DESCRIPTION OF DRAWINGS

For disclosure purposes, the term "high side" is usedin a conventional refrigeration sense to mean the portionof a vapor phase system from the compressor discharge tothe evaporator expansion valves, and the term "low side"means the portion of the system from the expansion valvesto the compressor suction. Also, "low" temperature shallhave reference to evaporator temperatures in the range of-35°F to -5°F or the associated frozen food and ice creamproduct temperatures in the range of minus -20°F to 0°F; and"standard" or "normal" (or "medium") temperature meansevaporator temperatures in the range of about 15°F to 40°For the associated non-frozen or fresh refrigerated foodtemperatures in the range of 25°F to 50°F.

Referring to Figures 1 and 9, there is illustrated arefrigeration unit, generally designated R, according to afirst embodiment of the present invention. Therefrigeration unit R is adapted for cooling a plurality ofproduct cooling zones, the unit R including refrigeratedcircuit components comprising multiple compressor means 21,and wherein in use the unit R is sized to be substantiallycontained within a footprint size of one of the coolingzones. In this description the term "footprint" of acooling zone is defined as the floor space occupied by aselected cooling fixture as viewed from above (or below).In this embodiment the unit R is adapted for use in afoodstore such as a supermarket and, accordingly, eachcooling zone generally comprises the product area of asingle merchandising cabinet orfixture 33. Of course, the location of the refrigeration units R may be outside theactual customer shopping arena as when the cooling zonesare storage fixtures or food preparation rooms. In eachcase the modular refrigeration unit R is sized toefficiently maintain its associated multiplicity ofdiscrete cooled zones at optimum refrigerationtemperatures, and it will be understood that these zonescomprise one or more of the supermarket coolers, freezers,preparation rooms or display merchandisers, the latterusually being an area department or combination lineup ofmerchandising fixtures operating at substantially the sametemperature.

As can be seen from Figures 4 and 5, one or more ofsuch merchandising cabinets orfixtures 33 may be combinedin-line and/or back-to-back. In this embodiment eightsuchmerchandising fixtures 33 are provided in which three (3)in-line cabinets 33a are arranged back-to-back with three(3) other in-line cabinets 33b, and these are capped byendcabinets 33c. In another arrangement the plural fixturescould be two single cabinets located on opposite sides of astore wall, or another arrangement of closelyadjacentfixtures 33. Further, a single unit R is shown on top andbridging across two of themerchandising cabinets 33although the preferred unit is sized to be accommodatedwithin the footprint of a single discrete fixture.

Referring to Figures 1-3 and 6-9, each of the modularunits R includes a condensing unit rack orbase 20constructed and arranged to mount and support the operativecomponents of aclosed refrigeration circuit 19 dedicatedto the refrigeration load requirements of its associateddiscrete product zones, merchandise cabinets orfixtures33. A typicalcondensing unit rack 20 of the present invention preferably has two small multiplexedhorizontalscroll compressors 21 or like variable capacity compressingmeans that is connected by adischarge header 22 to asystem condenser 12, also preferably located on therack 20in the preferred embodiment. In Figure 8 it will also beseen that a heat reclaimcoil 24 may be selectivelyconnected into the high side upstream of thecondenser 12.An oil separator (not shown) may be incorporated into thesystem 19 downstream of thedischarge manifold 22. In thepreferred embodiment, the closed (vapor compression)refrigeration system 19 may be critically charged withrefrigerant and therefore requires no liquid receiver toreceive the condensate outflow from thecondenser 12.However, for illustration aliquid receiver 26 is shown andmore than a critical amount of refrigerant may be employedwithout departing from the scope of the present invention.The high side of thecircuit 19 is connected byliquid line27 to anevaporative expansion valve 28 for the evaporativecooling means ormerchandiser evaporators 29 associatedwith the discreteproduct cooling zones 33 to be cooled. Onthe low side, the refrigerant expands and vaporizes in themerchandiser evaporators 29 removing heat from theproductzone 33 to maintain the preselected desired cooling. Theoutlets of theevaporators 29 connect bysuction lines 30to a common suction header ormanifold 31 and thence tothe suction side of thecompressors 21 to complete therefrigeration circuit.

In this embodiment the compressor means comprises thetwocompressors 21, which are multiplexed with one another- that is connected in parallel within the refrigerationcircuit. Preferably, thecompressors 21 are of thehorizontal scroll type as available from HITACHI under model numbers FL 200DL, FL 300DL, FL 400DL and FL 500DL.Provision of thehorizontal scroll compressors 21 withinthe unit R allows for the provision of a unit with a "lowprofile" which may be placed discreetly on top of aselectedmerchandising cabinet 33 so as to be at leastpartially obscured from view by persons moving around thefloor of the supermarket. It will be understood thatalthough the unit R is sized to fit within the profile of asingle fixture 33, in practice it may be placed to overlapor bridge across two or more fixtures.

Referring now to Figure 9, therefrigeration circuit19 of the unit R comprises a low side or suction line 30(S) and a high side or liquid line 27 (L). Thesuction line30 is connected to one end of a normally openisolationservice valve 25 which can be shut off for installation andservicing of the refrigeration unit R. The other side ofthe shut-offvalve 25 is connected through asuctionstrainer 36, which is connected throughsafety valve 37 tosuction header 27. Agauge 38 tees off ofsuction line 30and a further T-junction connects to acontrol transducer39, which senses the pressure of the refrigerant in thesuction line 30. If the pressure of the refrigerant fromthesuction line 30 falls below a predetermined level, theoperation of the unit R is controlled to ensure that thecompressors 21 are not damaged.

Thecompressors 21 are connected in parallel and areprovided withsolenoid valves 41 in by-pass lines 42 forcontrol at start up of thecompressors 21 to balancepressures. The high side of eachcompressor 21 is providedwith a one-way check valve 44 to isolate the high siderefrigeration circuit of each compressor at start up aspressures are balanced. Also teed to the output of each of thecompressors 21 aredischarge stats 45, and aninjectionstat 46 is connected to eachcompressor 21. Asafety switch47 is connected to the high side from the dischargemanifold, and discharge pressure read-out 48 andgaugeconnector 49 are provided.

It will be understood that the refrigeration systemunits R will generally include still other systemcomponents, such as defrost system means, systemperformance sensing and operating control panel andmicroprocessor apparatus, alarm systems and the like. Asshown in Figure 9, the unit R includes a connection to theliquidrefrigerant receiver 26 followed by a liquiddrier/desicator 53,liquid sight glass 54 and one-way valve55.

Although therefrigeration system condenser 12 ispreferably located on theunit rack 20, it may be roofmounted outside the food store for air cooled operation ina typical manner. When located on therack 20 it isessential that the sensible heat be rejected outside theshopping arena, and thecondenser 12 thus may be cooled innumerous ways. A coolant fluid circulating system C can beprovided to circulate a cooling fluid or coolant from aremote source 11 to the respective unit condenser/heatexchangers 12. Thus, the coolant system C derives a coolingliquid, such as water or glycol, from one or moreremotesources 11, 11A and 11B and circulates it to thecondenser12 of each modular unit R. Thecoolant source 11 may be asingle fluid cooling apparatus, such as a closed or openloop roof top cooling tower 11A or a ground source watersupply 11B, or a chiller system or recirculatingwatersource 11 or a combination of such alternate fluid coolingsources to assure a continuous supply of coolant at a substantially constant temperature. In this embodiment thecondenser 12 which is a plate type condenser, has a heatexchanger with acooling loop 12a from the remote coolingsource.

Thus, the invention further comprises the use of asecondary coolant system C for the direct distributed loadcooling of the heat exchange coils 29 of themerchandisers33 dedicated to the respective units R. As can be seen fromFigures 1, 3, 8 and 9, a coolant fluid input line 15 (F)and a fluid output line 16 (R) of thecondenser 12 areconnected to aremote cooling source 11 so as to provide aheat exchange relationship with thecondenser 12.

Referring to Figure 10, as stated above in alternateembodiment, the unit R may not provide condensing means onboard (on the rack 20), but condenser means 112 is providedat a location remote from the unit R. Theremote condenser112 may be roof mounted on the store and comprise an aircooled source.

Referring again to Figures 1-3, 6 and 7, the unit Rincludes acondensing unit rack 20 comprising a base orchassis 56 with fixedupstanding end walls 55 and aremovable lid or cover 57 which preferably is soundproofed. Thecompressors 21 and other refrigerationcomponents included in the unit R are mounted to thebase56, thecompressors 21 being mounted via a sub-frame. Therelatively compact size of the unit R may be discerned bythe following typical dimensions: length 1290 mm; depth 750mm; height 275 mm.

Referring to Figure 6, the electrical circuitry forthe unit R includes a main unit (pack)controller 59, apower supply circuit for eachcompressor 21, a circulatingfan 60 with afan guard 60a being placed thereover. As can further be seen from Figure 3, at least onevent 61 isprovided at oneend wall 55 of the unit R. The combinationof thefan 60 and vents 61 allow a through flow of airwithin the unit R.

In use, the unit R may be incorporated with therefrigeration system 19 for themerchandising cabinets 33,and which refrigeration unit components comprise, at leastthe multiple compressor means 21, and wherein in use theunit R is substantially sized for containment within thefootprint of one of themerchandising cabinets 33.

The refrigeration unit R may have an evaporatingtemperature of around -8°C, a suction return temperature ofaround 5°C, a condensing temperature of around 35°C, and aliquid temperature of around 32°C, in a preferredembodiment. Further it will be appreciated that a pluralityof combinedcompressors 21 may be provided so as to providethe desired refrigeration capacity, as detailed below.

Compressor models	HP
2 x FL 200DL	2/4
1 x FL 200DL plus 1 x FL 300DL	2/3/5
2 x FL 300DL	3/6
1 x FL 300DL plus 1 x FL 400DL	3/4/7
2 x FL 400DL	4/8
1 x FL 400DL plus 1 x FL 500DL	4/5/9
2 x FL 500DL	5/10

From the foregoing it will be appreciated that arefrigeration unit R according to a preferred embodiment ofthe present invention provides a compact, low profile,multi-compressor package which can be mounted on top of asingle display fixture or otherrefrigerated case 33 and takes up no floor space within the store. The unit Rdisclosed preferably has two parallel connected(multiplexed)scroll compressors 21 with a selected rangefrom 4HP to 10HP or more.

In a supermarket, a plurality ofsuch refrigerationsystems 19 may be provided so as to provide a refrigerationnetwork for the entire store. The units R may beconstructed and arranged to provide the low and mediumtemperature needs of the store. Further, it will beappreciated that a plurality ofcompressors 21 may beprovided so as to provide the requisite refrigerantcapacity, whereby different sizes of compressors may beutilized on thecondensing rack 20 of different units R. Itwill be known in the trade that a "condensing rack"necessarily includes the compressors as the prime mover ofthe condensing function, but that the condenser per se maybe provided at different locations other than the rack.

From the foregoing it will be appreciated that a unitR according to a preferred embodiment of the presentinvention provides a compact, low profile, multi-compressorpackage which can be mounted on top of a selected discretecabinet orfixture 33 and, since it takes up no floor spacewithin a shopping arena, it truly meets the requirementsfor optimum placement. The unit R according to thepreferred embodiment disclosed hereinbefore has twoparallel connectedhorizontal scroll compressors 21 with arange from about 2HP to 5HP each.

The preferred embodiment of the unit R disclosedhereinbefore is a fluid cooled unit, and employs aplateheat condenser 12. The unit R may also incorporate a smallliquid receiver 26, and an electrical control panel andcomplete internal refrigeration pipework and electrical wiring. With theevaporator 29 connections arranged fromthe top of themerchandising cabinets 33, external pipeworkis of an optimum length and relatively easy to install.

Another embodiment of the commercial refrigerationunit R of the present invention is shown in Figure 11. Thisunit is similar in many respects to that of Figures 1-10 inthat acondensing unit rack 20 houses aclosedrefrigeration system 19 with multiplexedcompressors 21 andthe closed (vapor compression)refrigeration system 19 maybe critically charged with refrigerant, and therefore,requires no liquid receiver to receive the condensateoutflow from thecondenser 12. The high side of thecircuit19 is connected byliquid line 27 to anevaporativeexpansion valve 28 for evaporator means 29 forming a partof theclosed refrigeration circuit 19 and beingconstructed and arranged with acoolant chiller unit 130.On the low side, the refrigerant in theevaporator 29removes heat from the coolant fluid and the evaporatoroutlet connects bysuction line 31 to the suction side ofthecompressors 21 to complete the closed refrigerationcircuit. Although therefrigeration system condenser 12 ispreferably located on theunit rack 20, it may be roofmounted outside the food store for air cooled operation ina typical manner.

This embodiment further comprises the use of asecondary coolant system 160 for the direct distributedload cooling of the heat exchange coils 129 of themerchandisers 133. Thus, in this embodiment the rackmountedrefrigeration system evaporator 29 is part of theheatexchanger chiller unit 130 for the coolant system.

Preferably the pumping means 142 for thesecondarycooling system 160 is also rack mounted, and is connected to circulate the glycol coolant fluid or the like throughthechiller heat exchanger 130 and thence outflow throughconduit 70 to its distributed load at each associatedmerchandiser display caseheat transfer coil 29. The coldcoolant fluid removes heat from the coil 129 (typically ofconventional tube and fin construction) and the fluid isthence circulated back to thepump 142 throughreturnconduits 46. The construction and operation of the modularsecondary system of this embodiment will be more fullyunderstood with reference to US 5,743,102 (incorporated byreference herein).

Since a principal feature of the invention is to placethe modular refrigeration unit R strategically in closeproximity to the dedicated cooling zone of an associatedmerchandiser 33 in order to eliminate the traditionalmachine back room, long piping connections and largerefrigerant requirements formerly required, it will be seenthat the mounting of the unit R on top of themerchandiser33 provides an optimum solution to meet all of theobjectives of the invention.

Claims (35)

1. A refrigeration unit (R) in combination with pluralclosely adjacent associated refrigerated fixtures (33;133)suitable for use in a commercial store, each of said fixtures (33;133)having a product zone and heat transfer cooling coil(29;129) for the refrigeration thereof,CHARACTERISED INTHAT said refrigeration unit (R) comprises a housing with afixture mounting profile constructed to be accommodatedwithin the footprint area of at least one of saidassociated fixtures (33;133) and being arranged to supportselected refrigeration components of a closed refrigerationcircuit for supplying the refrigeration requirements of allassociated fixtures (33;133), which said components includeplural vapor phase compressors (21) and a closely coupledcooling loop (27,30) connected with the heat transfercooling coils (29;129) of all associated fixtures (33;133).
2. The refrigeration unit (R) of claim 1, wherein two ofsaid plural compressors (21) are scroll compressors.
3. The refrigeration unit (R) of claim 1, wherein two ofsaid plural compressors (21) are scroll compressors havingdifferent capacities.
4. The refrigeration unit (R) of claim 1, wherein saidunit (R) has a horizontal mounting profile accommodatingside by side horizontally disposed compressors.
5. The refrigeration unit (R) of claim 4, wherein the onesaid associated fixture (33;133) is free standing within thecommercial store, and the refrigeration unit (R) isaccommodated over the top of said one associated fixture(33;133) with its horizontal profile abutting the top wall thereof.
6. The refrigeration unit (R) of claim 1, wherein saidrefrigeration unit (R) has a vertical mounting profileaccommodating vertically disposed compressors.
7. The refrigeration unit (R) of claim 6, wherein one ofsaid associated fixtures (33;133) can be positioned against avertical wall structure of the commercial store, and therefrigeration unit (R) is accommodated over the top of saidone associated fixture (33;133) with its vertical profileabutting such wall structure.
8. 'The refrigeration unit (R) of claim 1, wherein saidhousing includes a mounting base (56) and end walls (55)connected thereto for accommodating the selectedrefrigeration components and for mounting the pipingconnections of the closely coupled cooling loop (27;30).
9. The refrigeration unit (R) of claim 8, wherein saidhousing includes cover means (57) for covering the entiremounting base (56) between the end walls (55) to encase therefrigeration components therein.
10. The refrigeration unit (R) of claim 9, wherein thehousing is constructed and arranged to provide a soundabsorbing barrier.
11. The refrigeration unit (R) of claim 8, wherein saidhousing is constructed and arranged to internallyaccommodate piping connections extending externally thereofthrough at least one end wall (55) to be piped to the heattransfer cooling coils (29;129)for all associated fixtures(33;133).
12. The refrigeration unit (R) of claim 1, includingcontrol panel instrumentation for monitoring the operationof the refrigeration unit (R).
13. The refrigeration unit (R) of claim 1, wherein saidhousing comprises a mounting base (56) forming a condensingunit rack (20) for supporting said plural compressors (21),said compressors (21) being part of a closed vapor phaserefrigeration system that includes liquid and suction lineconnections (27;30).
14. The refrigeration unit (R) of claim 13, which includesa condenser (12) as a part of the closed vapor phaserefrigeration system.
15. The refrigeration unit (R) of claim 14, wherein saidcondenser (12) is part of a first heat exchanger supportedon the mounting base (56) and having condenser coolingmeans.
16. The refrigeration unit (R) of claim 15, wherein themounting base (56) of said condenser (12) is mounted on thecondensing unit rack (20).
17. The refrigeration unit (R) of claim 15, wherein saidcondenser cooling means comprises an external liquidcooling source selected from a class consisting of a fluidcooling tower, a coolant chiller system, a cold groundwater supply, a dedicated refrigeration system or an aircooled heat exchanger.
18. The refrigeration unit (R) of claim 13, wherein saidcondenser (12) is remotely located from the housing and condensing unit rack (20) thereof and is either watercooled or air cooled.
19. The refrigeration unit (R) of claim 14, wherein theheat transfer cooling coils of the associated fixtures(33;133) comprise evaporator coils as part of the closedvapor phase refrigeration circuit and are connected betweensaid condenser (12) on the high side and said pluralcompressors (21)on the low side.
20. The refrigeration unit (R) of claim 14, which includesan evaporative cooling heat exchanger having an evaporatorcoil as part of the closed vapor phase refrigerationsystem.
21. The refrigeration unit (R) of claim 20, wherein saidheat transfer cooling coil comprises a liquid cooled heatexchanger as part of a glycol-type liquid coolant systemhaving a cooling phase in which the cooling loop isconnected to the evaporative cooling heat exchanger.
22. The refrigeration unit (R) of claim 1 in combinationwith said plural associated refrigeration fixtures (33;133)said plural compressors (21) being connected throughcooling loops with the heat transfer cooling loop of eachfixture (33;133).
23. The combination of at least two discrete, closelyadjacent associated refrigerated fixtures (33;133) suitable for use in acommercial store, each of which fixtures has a cabinet witha top wall surface and having a product zone and a heattransfer cooling coil (29;129) for the refrigeration of itsproduct zone with a refrigeration unit (R)CHARACTERISED INTHAT the refrigeration unit (R) comprises a housing with a mounting profile constructed so as to be accommodatedwithin the top wall footprint area of at least one of saidrefrigerated fixtures (33;133) and being arranged tosupport selected refrigeration components of a closedrefrigeration circuit including plural vapor phase scrollcompressors (21) optionally having different capacities,and a closely coupled cooling loop (27,30) connected tosupply the refrigeration requirements of the heat transfercooling coils (29;129) of all associated refrigeratedfixtures (33;133).
24. The combination of claim 23, wherein saidrefrigeration unit (R) has a horizontal base mountingprofile and accommodates at least two horizontally disposedcompressors (21), and said refrigerated fixture (33;133) isfree standing adjacent to an associated other refrigeratedfixture (33;133) with the refrigeration unit (R) beingaccommodated with its horizontal base profile abutting thetop wall of said one refrigerated fixture (33;133).
25. The combination of claim 23, wherein saidrefrigeration unit (R) has a vertical mounting profile andaccommodates at least two vertically disposed compressors(21).
26. The combination of claim 23, wherein said housingincludes the mounting base (56) for supporting the selectedrefrigeration components and end walls (55) provided withpiping connections for the closely coupled cooling loop,and said housing also includes a cover (57) for enclosingthe entire mounting base (56) between the end walls (55) tothereby encase the refrigeration components therein.
27. The combination of claim 23, wherein the housing is constructed and arranged to provide a sound absorbingbarrier.
28. The combination of claim 23, which includes acondenser (12) as a part of the closed vapor phaserefrigeration circuit of said refrigeration unit (R).
29. The combination of claim 28, wherein said condenser ispart of a first heat exchanger supported on the housing andincludes condenser cooling means.
30. The combination of claim 29, wherein said condensercooling means comprises an external cooling source selectedfrom a class consisting of a fluid cooling tower, a coolantchiller system, a cold ground water supply, a dedicatedrefrigeration system or an air cooled heat exchanger.
31. The combination of claim 28, wherein said condenser(12) is remotely located from the housing and is eitherwater cooled or air cooled.
32. The combination of claim 28, wherein the heat transfercooling coils of the refrigerated fixtures (33) compriseevaporator coils as part of the closed vapor phaserefrigeration circuit and are connected between saidcondenser (12) on the high side and said plural compressors(21) on the low side.
33. The combination of claim 28, which includes anevaporative cooling heat exchanger having an evaporatorcoil as part of the closed vapor phase refrigerationcircuit, and in which said heat transfer cooling coils ofsaid refrigerated fixtures (33;133) comprise liquid cooledheat exchangers as part of a glycol-type liquid coolant system having a cooling phase in which its cooling loop isconnected in heat exchange relation to the evaporativecoil.
34. A refrigeration unit (R) as claimed claim 1, whereinthe housing has a fixture mounting profile constructed tobe accommodated within the footprint area of one of saidassociated fixtures (33;133).
35. The combination of claim 23, wherein the housing has afixture mounting profile constructed to be accommodatedwithin the footprint area of one of said associatedfixtures (33;133).

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