Refrigeration unit

Abstract

The present invention discloses a refrigeration unit, comprising a cold side, a hot side and an insulation between said hot and cold sides; wherein the cold side includes: two cold side fans mounted on a plate; two evaporators disposed on opposite sides of the plate; two bulkheads transversally disposed to the evaporators and near the ends of said evaporators; a partition disposed between the two cold side fans and between the two bulkheads; an structural support, disposed below the insulation, for fixation of the two evaporators, two bulkheads, and partition; wherein the hot side includes: a hot side base with two variable speed compressors, two frequency inverters, one microcontroller, two intermediate heat exchangers, two solenoid valves, two thermal expansion valves, and two condensers.

Description

"REFRIGERATION UNIT"TECHNICAL FIELD

[0001] The present invention relates to a refrigeration unit for cold rooms and walk-in chambers that store products which require refrigeration . More speci fically, the present invention discloses a refrigeration unit preferably installed at the roof of cold rooms and walk-in chambers located, for example , in supermarkets , restaurants , retailers , and other places that need to refrigerate products . BACKGROUND OF THE INVENTION

[0002] In most of the refrigeration application segments the use of natural refrigerants is already a reality . Despite still being allowed to operate with synthetic refrigerant fluid alternatives , companies have been pushed to implement green solutions from several environment protection agencies . Besides this , the traditional refrigeration machine rooms are also large and noisy . Based on that , the refrigeration market segment seeks refrigeration unit solutions that combine high ef ficiency, low environment impact , low noise , low footprint and competitive cost for installation and maintenance . These solutions require not only high ef ficiency components , but the optimal use of these components in such a way the refrigeration unit achieves its maximum ef ficiency in a compact design .

[0003] Further, international safety standards delimit the amount of flammable refrigerant fluid anddefine some rules to determine its applicability, aiming to avoid the occurrence of accidents with flammable mixtures. To employ a flammable refrigerant, it is necessary to comply with some specific safety conditions that take in consideration, not only, but mainly, the flammable Refrigerant Ignition Source availability, the class of the refrigerant, amount of refrigerant, and the volume of the ambient where a leakage can occur.

[0004] Due to these safety requirements, special features are specified for the refrigeration unit designs, installation, and final application. These features increase the complexity of the product and its installation, with impact in the cost of the complete solution. On the other hand, natural refrigerants are the best option in terms of energy efficiency and low ambient impact .

[0005] Therefore, there is a challenge in designing and constructing compact refrigeration units with high cooling capacity and high energy efficiency employing natural refrigerants.SUMMARY

[0006] The objective of the present invention is to provide a refrigeration unit that avoids the drawbacks of the prior art.

[0007] This objective is achieved by means of a refrigeration unit with two refrigeration circuits, comprising a cold side, a hot side and an insulation between said cold and hot sides;wherein the cold side includes : a structural support disposed below the insulation; two evaporators parallel to each other disposed on opposite sides of the structural support ; two bulkheads transversally disposed in relation to the evaporators and each bulkhead fixed to the ends of said evaporators ; a partition, said partition di sposed between and parallel to the two bulkheads and between two cold side fans , wherein said two cold side fans are provided in two holes of an inferior plate ; wherein the two evaporators , the two bulkheads , and the partition are disposed below the structural support ; and wherein the inferior plate is provided below the two evaporators , the two bulkheads , and the partition; wherein the hot side includes : a hot side base disposed above the insulation, said hot side base supporting a first variable speed compressor, a first inverter, and a first thermostatic expansion valve disposed in a first hot base side ; a second variable speed compressor, a second inverter, and a second thermostatic expansion valve disposed in a second hot base side ; and the hot side further includes , in a third hot base side , two water condensers and balance valves mounted to the water inlet / outlet of said water condensers .

[0008] In the refrigeration unit according to thepresent invention the first variable speed compressor is provided between the first inverter and the first thermostatic expansion valve , and the second variable speed compressor is provided between the second inverter and the second thermostatic expansion valve .

[0009] Additionally, according to the present invention the hot side base further supports a microcontroller provided adj acent to the first inverter .

[0010] Further, according to the present invention the first hot base side and the second hot base side are parallel to each other .

[0011] In addition, according to the present invention the third hot base side is between the first and second hot base sides .

[0012] Additionally, according to the present invention the hot side further comprises a first water pipe and a second water pipe mounted to the balance valves , and a third water pipe connected to a water supply .

[0013] The present invention also describes a refrigeration unit with two refrigeration circuits , comprising a cold side , a hot side and an insulation between said cold and hot sides ; wherein the cold side includes : a structural support disposed below the insulation; two evaporators parallel to each other disposed on opposite sides of the structural support ;two bulkheads transversally disposed in relation to the evaporators and each bulkhead fixed to the ends of said evaporators ; a partition, said partition di sposed between and parallel to the two bulkheads and between two cold side fans , wherein said two cold side fans are provided in two holes of an inferior plate ; wherein the two evaporators , the two bulkheads , and the partition are disposed below the structural support ; and wherein the inferior plate is provided below the two evaporators , the two bulkheads , and the partition; wherein the hot side includes : a hot side base disposed above the insulation, said hot side base supporting a first micro-channel condenser and a first set o f hot side fans disposed in the between of the first and second hot base side ; a second micro-channel condenser and a second set of hot side fans disposed in the between of the first and second hot base side ; and wherein the first and second set of hot base fans are disposed in front of the first and second micro-channel condensers , respectively, with said first and second sets of fans being closer to the center of the base than the micro-channel condensers .

[0014] In the refrigeration unit according to the present invention, the hot side base further supports a first variable speed compressor, a first inverter, and afirst thermostatic expansion valve in the first hot base side ; and a second variable speed compressor, a second inverter, and a second thermostatic expansion valve in the second hot base side .

[0015] Additionally, according to the present invention the first hot base side and the second hot base side are parallel to each other ;

[0016] Additionally, the hot side also comprises an air flow deflector in order to drive out the hot air from the first set of fans to one side of the unit where a second air deflector drives the air from the second set of fans to the other side of the unit , allowing a properly air flow over the first and second compressors and inverters respectively .

[0017] In addition, according to the present invention the fans of the first set of hot side fans are provided side by side , and the fans of the second set of hot side fans are provided side by side .

[0018] Further, according to the present invention the first and second micro-channel condensers are provided in the edge of the first and second hot base sides , respectively .

[0019] The present invention also describes a refrigeration unit with four refrigeration circuits , comprising a cold side , a hot side and an insulation between said cold and hot sides ; wherein the cold side includes :a structural support disposed below the insulation; four evaporators separated in two pair of evaporators parallel to each other disposed on opposite sides of the structural support ; two bulkheads transversally disposed in relation to the two pair of evaporators and each bulkhead fixed to the ends of said two pair of evaporators ; a partition, said partition di sposed between and parallel to the two bulkheads and between two cold side fans , wherein said two cold side fans are provided in two holes of an inferior plate ; wherein the two pair of evaporators , the two bulkheads , and the partition are disposed below the structural support ; wherein the inferior plate is provided below the two pair of evaporators , the two bulkheads , and the partition; and wherein each of the four evaporators belongs to its own refrigeration circuit , comprising four refrigeration circuits in total ; wherein the hot side includes : a hot side base disposed above the insulation, said hot side base supporting a first , a second, a third, and a fourth variable speed compressor disposed side by side ; a first , a second, a third, and a fourth inverter disposed side by side ; wherein the first inverter is provided in front of the first compressor, the second inverter is provided in frontof the second compressor, the third inverter is provided in front of the third compressor, and the fourth inverter is provided in front of the fourth compressor ; a first , a second, a third, and a fourth thermostatic expansion valve , wherein the first and third thermostatic valves are adj acent to each other and disposed in a first hot base side , whereas the second and fourth thermostatic valves are adj acent to each other and disposed in a second hot base side ; wherein the first and second hot base sides are parallel to each other ; wherein the hot side base further supports a microcontroller disposed in the vertex between the first hot base side and a third hot base side , wherein the first and third hot base sides are perpendicular to each other ; wherein the base supports a fan in the first hot base side , said fan provided between the microcontroller and the third thermostatic expansion valve ; wherein the hot side further comprises , between the second and fourth thermostatic expansion valves and the microcontroller, four water condensers disposed parallel to each other ; and wherein the inverters are closer to the center of the hot side base than the compressors .

[0020] Additionally, the present invention also describes a refrigeration unit with four refrigeration circuits , comprising a cold side , a hot side and an insulation between said cold and hot sides ;wherein the cold side includes : a structural support disposed below the insulation; four evaporators separated in two pair of evaporators parallel to each other disposed on opposite sides of the structural support ; two bulkheads transversally disposed in relation to the two pair of evaporators and each bulkhead fixed to the ends of said two pair of evaporators ; a partition, said partition di sposed between and parallel to the two bulkheads and between two cold side fans , wherein said two cold side fans are provided in two holes of an inferior plate ; wherein the two pair of evaporators , the two bulkheads , and the partition are disposed below the structural support ; wherein the inferior plate is provided below the two pair of evaporators , the two bulkheads , and the partition; and wherein each of the four evaporators belongs to its own refrigeration circuit , comprising four refrigeration circuits in total ; wherein the hot side includes : a hot side base disposed above the insulation, said hot side base supporting a first , a second, a third and a fourth micro-channel condenser, wherein the first and third micro-channel condensers are disposed side by side in a first hot base side , and wherein the second and fourthmicro-channel condensers are disposed side by side in the first hot base side ; a first , a second, a third, and a fourth hot side fan, wherein the first and third hot side fans are disposed parallel to each other in a first hot base side , and wherein the second and fourth hot side fans are disposed parallel to each other in a first hot base side ; wherein the first , second, third, and fourth hot side fans are disposed in front of the first , second, third, and fourth micro-channel condensers , respectively, in a way the hot side fans are closer to center of the hot side base than the micro-channel condensers ; wherein the hot side base further supports a first , a second, a third, and a fourth inverter, wherein the first and fourth inverters are provided laterally to the first and fourth compressors in a first hot base side , and wherein the second and third inverters are provided laterally to the second and third compressors in a first hot base side ; wherein the second hot side base further supports a first , a second, a third, and a fourth variable speed compressor provided in the center of said first hot side base ; and wherein the second hot base sides is assembled above and in the center of the first hot base sides .

[0021] According to the present invention each of the two pair of evaporators comprises a first evaporator with 4±0 . 5 fins per inch ( 6mm fins spacing) , and a secondevaporator with 6±0 . 5 fins per inch ( 6mm fins spacing) , wherein the first and second evaporators are disposed parallel and contacting each other ; and wherein the fin density of the second evaporator is from 22 % to 86% higher than the fin density of the first evaporator .

[0022] Additionally, according to the present invention the first evaporator is fixed closer to the center of the refrigeration unit than the second evaporator .

[0023] In addition, according to the present invention the first thermostatic valve is disposed in the corner between the third condenser and third thermostatic expansion valve , the second thermostatic expansion valve is disposed in the corner between the fourth condenser and the fourth thermostatic expansion valve and the third expansion valve is disposed between the third inverter and the first thermostatic expansion valve whi le the fourth thermostatic valves is disposed between the fourth inverter and the second thermostatic expansion valve .

[0024] Another advantage of the present invention consists of providing a thermal insulation made of Expanded Polypropylene "EPP" between the hot and cold sides , reducing the absorption of humidity when compared to traditional Expanded Polystyrene "EPS" or Rigid Polyurethane "PUR" (when no humidity barriers are available ) . The "EPP" is commonly used as thermal insulation in automotive air conditioning appliances , butnot usual for commercial appliances. The EPP is expanded with water and Carbon dioxide, resulting in a safe component as no flammable expanding agent is applied during the manufacturing process.

[0025] Another advantage of the present invention is the possibility of having several configurations in the same platform: water-cooled condenser, air-cooled condenser, two refrigeration circuits, four refrigeration circuits, medium temperature application (storage temperature in the within of 12°C to -2.2°C)and low temperature application (storage temperature in the within of -9°C to -26°C) , all this options allowing the installer to combine the options as per the application needs, heat demand, restrictions in the installation sites and customer requirements. From the manufacturing point of view, these designs allow to combine cold side from one design with hot side from the other design, reducing the amount of components and simplifying the manufacturing processes.

[0026] A further advantage of the present invention, where four refrigeration circuits are applied, is the fact that the use of evaporators in pair, with similar cooling capacity, allows an efficient refrigerating cycles and, as consequence, an efficient refrigeration unit. As when the air flow, already cooled and dehumidified, leaves the first evaporator and enters the second evaporator, with a temperature difference between such air flow and the second evaporator smaller than the temperature difference between the air flow coming from the cold side fans and the firstevaporator, the second evaporator must have a higher fin density in order to have a cooling capacity similar to the one of the first evaporator . With this combination, both evaporator and refrigeration circuits present similar performance in terms of cooling capacity .BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The obj ectives and advantages of the present invention will become clearer through the following detailed description of the examples and non- limiting drawings presented at the end of this document :

[0028] Figure 1 illustrates a perspective view of an assembled compact refrigeration unit according to a preferred embodiment of the present invention .

[0029] Figure 2 illustrates a perspective view of the cold side of the refrigeration unit according to a preferred embodiment of the present invention .

[0030] Figure 3A illustrates a perspective exploded view of the cold side of the refrigeration unit with two refrigeration circuits according to a first or second preferred embodiment of the present invention .

[0031] Figure 3B illustrates a perspective exploded view of the cold side of the refrigeration unit with four refrigeration circuits according to a third or fourth preferred embodiment of the present invention .

[0032] Figure 4A illustrates an upper view of the water-cooled condenser version of the hot side applied to the first preferred embodiment of the present invention .

[0033] Figure 4B illustrates an upper view of the air-cooled condenser version of the hot side applied to the second preferred embodiment of the present invention .

[0034] Figure 5A illustrates an upper view of the water-cooled condenser version of the hot side applied to the third preferred embodiment of the present invention .

[0035] Figure 5B illustrates an upper view of the air-cooled condenser version of the hot side applied to the fourth preferred embodiment of the present invention .

[0036] Figure 6 illustrates a cut perspective view of the air-cooled condenser version of the hot side of the refrigeration unit according to the first or second preferred embodiment of the present invention . DETAILED DESCRIPTION

[0037] Figure 1 illustrates a perspective view of an assembled compact refrigeration unit 100 , preferably installed at the roof of cold rooms and walk-in chambers located, for example , in supermarkets , restaurants , and other places that need to refrigerate products , according to a preferred embodiment of the present invention . According to Figure 1 , said refrigeration unit 100 comprises a bottom cold side 200 and an upper hot side 300 . Preferably, the refrigeration unit 100 is installed at the roof in way that the cold side 200 remains inside the cold room or walk-in chamber and the hot side 300 remains outside .

[0038] According to the first or second preferred embodiment , the refrigeration unit 100 comprises twocondensing units and two evaporating units, forming two complete refrigeration circuits.

[0039] Figure 2 depicts a perspective view of the cold side 200 in an assembled state. Further, Figure 3A illustrates a perspective exploded view of said cold side 200 according to the first or second preferred embodiment of the present invention.

[0040] According to Figure 3A, there is an insulation 210 between the cold 200 and hot 300 sides. Such insulation 210 is preferably made of Expanded Polypropylene "EPP" and aims to reduce thermal conduction between hot 300 and cold 200 sides and avoid water condensation in the hot side 300. Additionally, the insulation 210, has a thickness in the range of 35 mm to 45 mm (0.035 m to 0.045 m) , which is substantially thinner than insulations of the prior art, around 127 mm (0.127 m) . The space saved due to the lower thicknesses of the insulation 210 is used to accommodate a portion of the evaporators 230 (described in more details below) , reducing the penetration of such evaporators into the useful region of the cold room around 230 mm (0.23 m) .

[0041] Still according to Figure 3A, the cold side 200 further comprises a structural support 220 disposed below the insulation 210. The cold side 200 comprises, below the structural support 220, two evaporators 230 parallel to each other disposed on opposite sides of the structural support 220; two bulkheads 250A transversally disposed in relation to the evaporators 230 and each bulkhead 250A fixed to the ends of said evaporators 230; apartition 250B, said partition 250B disposed between and parallel to the two bulkheads 250A and said partition 250B disposed between two cold side fans 260 , wherein said two cold side fans 260 are provided in two holes of an inferior plate 240 , said inferior plate 240 disposed below the structural support 220 , evaporators 230 , bulkheads 250A, and partition 250B ; and grids 270 disposed below the two cold side fans 260 . Preferably, two cold side fans 260 and two grids 270 are used . The partition 250B creates a barrier between the cold side fans 260 , in way that if one of such cold side fans 260 stops working, the remaining one will keep a sufficient air- flow through the evaporators 230 . The evaporators 230 , bulkheads 250A and partition 250B are fixed to an inner face of the structural support 220 by means , for example , of screws or bolts .

[0042] According to the third or fourth preferred embodiment , illustrated in Figure 3B, the refrigeration unit has four refrigeration circuits . The dif ference between the cold side with four circuits and two circuits is the fact that the cold side with two circuits has one evaporator each s ide while the cold side with four circuits has two evaporators each side .

[0043] Therefore , the cold side with four circuits has four evaporators separated in two pair of evaporators 231 parallel to each other disposed on opposite sides of the structural support 220 , each pair of evaporators 231 comprising a first evaporator 231A with 4±0 . 5 fins per inch ( 6mm fins spacing) ; and a second evaporator 231B with 6±0 . 5fins per inch ( 4mm fins spacing) , wherein the first 231A and second 231B evaporators are disposed parallel and contacting each other . Therefore , the first evaporator 231A has a fin density lower than the fin density of the second evaporator 231B, wherein the fin density of the second evaporator 231B is from 22 % to 86% higher than the fin density of the first evaporator 231A. Additionally, each of the four evaporators belongs to its own refrigeration circuit . Hence , a primary evaporator belongs to a first refrigeration circuit , a secondary evaporator belongs to a second refrigeration circuit , a third evaporator belongs to a third refrigeration circuit , and a fourth evaporator belongs to a fourth refrigeration circuit .

[0044] Each pair of evaporators 231 is assembled in a manner that the warm and humid air flow, coming from the two cold side fans 260 , approaches the first evaporator 231A prior to the second evaporator 231B . In this sense , the first evaporator 231A is installed closer to the two cold side fans 260 in order to capture the most part of the air flow humidity and cool it . The second evaporator 231B is installed after the first evaporator 231A . Thus , the second evaporator 231B further removes heat from the air flow previously cooled and dehumidi fied by the first evaporator 231A.

[0045] Figure 4A illustrates an upper view of the water-cooled condenser version o f the hot side with two refrigeration circuits , according to the first preferred embodiment .

[0046] According to Figure 4A, said hot side 300 comprises a hot side base 301 , said base hot side base 301 disposed above the insulation 210 and supporting a first 310A and a second 310B variable speed compressor disposed on opposite sides of the base 301 , a first 320A and a second 320B inverter disposed on opposite sides of the base 301 , and a first 330A and a second 330B thermostatic expansion valve also disposed on opposite sides of the base 301 . Therefore , the first variable speed compressor 310A, the first inverter 320A, and the first thermostatic expansion valve 330A are disposed in a first hot base side 301A, whereas the second variable speed compressor 310B, the second inverter 320B, and the second thermostatic expansion valve 330B are disposed in a second hot base side 301B, wherein the first 301A and second 301B hot base sides are parallel to each other . Additionally, the first variable speed compressor 310A is provided between the first inverter 320A and first thermostatic expansion valve 330A, while the second variable speed compressor 310B is provide between the second inverter 320B and second thermostatic expansion valve 330B .

[0047] The hot side base 301 further supports a microcontroller 340 provided adj acent to the second inverter 320B .

[0048] Still according to Figure 4A, the hot side 300 further comprises two water condensers 410 , balance valves 420 mounted to the water inlet / outlet of the condensers 410 by, for example , threading or fitting; a first water pipe430 and a second water pipe 431 mounted to the balance valves 420 by, for example , threading or fitting; and a third water pipe 432 connected to a water supply . The water pipes 430 , 431 , 432 are fixed by, for example , threading or fitting, to a water connection 450 which creates a flow of water between them . Additionally, the third water pipe 432 is connected to the water supply by means of a normally open solenoid valve 440 , which allows the control of water flow . The condensers 410 , the balance valves 420 , the pipes 430 , 431 , 432 , the solenoid valve 440 , and the water connection 450 are provided in a third hot base side 301C, said third hot base side 301C between the first 301A and second 301B hot base sides .

[0049] During the defrost cycle of the refrigeration unit 100 , the normally open solenoid valve 440 closes the water flow through the water condensers 410 . Thi s process keeps the condensers 410 warm, as the heat exchanging process is degraded due to the lack of water . Then, the refrigerant fluid present in the condensers 410 , that was condensed until this moment , evaporates and migrates to the hot gas cycle , increasing the amount of refrigerant gas available in the system for the defrost cycle , increasing the ef ficiency of the refrigeration process as a whole .

[0050] Figure 4B illustrates the upper view of the air-cooled condenser version of the hot side with two refrigeration circuits , according to the second preferred embodiment . The arrangement of the cold side 200 does notchange when an air-cooled version of the hot side 300 is employed instead of a water-cooled version .

[0051] In the second preferred embodiment , the hot side base 301 supports a first 510A and a second 510B micro-channel condenser disposed on opposite sides of the side base 301 , and a first 520A and a second 520B set of hot side fans disposed on opposite sides of said base 301 . Therefore , the first micro-channel condenser 510A and the first set of hot side fans 520A are disposed in the between of a first hot base side 301A and second hot base side 301B, whereas the second micro-channel condenser 510B and the second set of hot side fans 520B are disposed in the between of the first hot base side 301A and the second hot base side 301B, wherein the first 301A and second 301B hot base sides are parallel to each other . The fans of the first set of hot side fans 520A are provided side by side , and the fans of the second set o f hot side fans 520B are provided side by side . The first 510A and second 510B micro-channel condensers are provided in the edge of the first 301A and second 301B hot base sides , respectively . In this sense , the f irst 520A and second 520B sets of hot base fans are disposed in front of the first 510A and second 510B micro-channel condensers , respectively, with said first 520A and second 520B sets being closer to the center of the base 301 than the first 510A and second 510B microchannel condensers . According to Figure 4B, each set of hot side fans comprises three fans , however, one , two , four or more fans can be provided in each set .

[0052] Further according to Figure 4B, the hot side base 301 supports a first 310A and a second 310B variable speed compressor disposed on opposite sides of said base 301 , a first 320A and a second 320B inverter disposed on opposite sides of said base 301 , and a first 330A and a second 330B thermostatic expansion valve also disposed on opposite sides of said base 301 . Therefore , the first variable speed compressor 310A, the first inverter 320A, and the first thermostatic expansion valve 330A are disposed in a the hot base side 301A, whereas the second variable speed compressor 310B, the second inverter 320B, and the second thermostatic expansion valve 330B are disposed in a the hot base side 301B . Additionally, the first variable speed compressor 310A is provided between the first inverter 320A and the first thermostatic expansion valve 330A, while the second variable speed compressor 310B i s provide between the second inverter 320B and the second thermostatic expansion valve 330B .

[0053] Additionally, the hot side also comprises two air flow deflector 350 in order to drive out the hot air from the condenser to the surrounding ambient . In this sense , the air flow generated by the set of fans 520A is driven out of the unit by the air deflector 350A while the air flow generated by the set of fans 520B is driven out of the unit by the air deflector 350B . This arrangement also allows a properly air flow over the compressors and inverters , where the deflector 350A drives the air from the fans 520A over the compressor 310A and inverter 320A andthe deflector 350B drives the air from the fans 520B over the compressor 310B and inverters 320B respectively .

[0054] Figure 5A illustrates an upper view of the water-cooled condenser version of the hot side with four refrigeration circuits , according to the third preferred embodiment .

[0055] According to Figure 5A, said hot side 300 comprises a hot side base 301 , said hot side base 301 disposed above the insulation 210 and supporting a first 310A, a second 310B, a third 310C, and a fourth 310D variable speed compressor disposed side by side , a first 320A, a second 320B, a third 320C, and a fourth 320D inverter disposed side by side , wherein the first inverter 320A is provided in front of the f irst compressor 310A; the second inverter 320B is provided in front of the second compressor 310B ; the third inverter 320C is provided in front of the third compressor 310C ; and the fourth inverter 320D is provided in front of the fourth compressor 310D . In this sense , the inverters 320A, 320B, 320C, 320D are closer to the center of the hot side base 301 than the compressors 310A, 310B, 310C, 310D .

[0056] The hot side base 301 further supports a first 330A, a second 330B, a third 330C, and a fourth 330D thermostatic expansion valve , wherein the first 330A and third 330C thermostatic expansion valves are adj acent to each other and disposed in the f irst hot base side 301A, whereas the second 330B and fourth 330D thermostatic expansion valves are adj acent to each other and disposed inSUBSTITUTE SHEET (RULE 26)the second hot base side 301B . As such, the first and the third thermostatic valve 330A and 330C are disposed in front of the third compressor 310C and beside the third 320C, and the second 330b and fourth 330D thermostatic expansion valves are disposed beside the third base side 301C and the fourth inverter 320D .

[0057] Still according to Figure 5A, the hot side base 301 further supports a microcontroller 340 disposed in the vertex between the first hot base side 301A and a third hot base side 301C . As such, the first hot base side 301A and the second hot base side 301B are parallel to each other and both are perpendicular to the third 301C hot base side .

[0058] The hot side 300 further comprises , between the second 330B and fourth 330D thermostatic expansion valves and microcontroller 340 , four water cooled condensers 410 disposed parallel to each other . In addition, the base 301 supports a fan 350 in the first hot base side 301A, said fan 350 provided between the microcontroller 340 and the third thermostatic expansion valve 330C .

[0059] Figure 5B illustrates the upper view of the air-cooled condenser version of the hot side with four refrigeration circuits , according to the fourth preferred embodiment . The arrangement of the cold side 200 does not change when an air-cooled version of the hot side 300 is employed instead of a water-cooled version .SUBSTITUTE SHEET (RULE 26)

[0060] According to Figure 5B, the hot side base 301 supports a first 510A, a second 510B, a third 510C and a fourth 510D micro-channel condenser, wherein the first 510A and third 510C micro-channel condensers are disposed side by side in a first hot base side 301A, and wherein the second 510B and fourth 510D micro-channel condensers are disposed side by side in the first hot base side 301A.

[0061] The hot side base 301 further supports , a first 520A, a second 520B, a third 520C, and a fourth 520D hot side fan, wherein the first 520A and third 520C hot side fans are disposed parallel to each other in a first hot base side 301A, and wherein the second 520B and fourth 520D hot side fans are disposed parallel to each other in the first hot base side 301A.

[0062] The first 520A, second 520B, third 520C, and fourth 520D hot side fans are disposed in front of the first 510A, second 510B, third 510C, and fourth 510D microchannel condensers , respectively . Therefore , the hot side fans are closer to center of the hot side base 301 than the micro-channel condensers .

[0063] Further according to Figure 5B, the hot side base 301 supports a first 310A, a second 310B, a third 310C, and a fourth 310D variable speed compressor provided in the center o f said hot s ide base 301 , all of them assembled on a second hot side base 301B ; a first 320A, a second 320B, a third 320C, and a fourth 320D inverter, wherein the first 320A and fourth 320D inverters are provided laterally to the first 310A and fourth 310DSUBSTITUTE SHEET (RULE 26)compressors , and wherein the second 320B and third 320C inverters are provided laterally to the second 310B and third 310C compressors a first 330A, a second 330B, a third 330C, and a fourth 330D thermostatic expansion valves , wherein the first expansion valve 330A is provided in the first hot base side 301A in the corner between the third fan 520C and the third thermostatic expansion valve 330C, wherein the second expansion valve 330B is provided in the first hot base side 301A in the corner between the fourth fan 520D and the fourth thermostatic expansion valve 330D, wherein the third expansion valve 330C is provided in the first hot base side 301A between the first thermostatic expansion valve 330A and the third inverter 320C, and wherein the fourth expansion valve 330D is provided in the first hot base side 301A between the second thermostatic expansion valve 330B and the fourth inverter 320D .

[0064] According to Figures 4B, 5B, and 6 , the design of the second and fourth preferred embodiments allows to employ several air outlet openings 550 at the perpendicular sides of the condensers , as observed in Figure 6 . Lateral outlet air openings are advantageous , as some of the cold rooms or walk-in are installed very close to building ceilings and, in some cases , there is no room to accommodate parts to remove the hot air from the condensers at the top of the refrigeration unit .

[0065] In addition to the embodiments presented above , the same inventive concept can be applied to other alternatives or possibilities of using the invention, forSUBSTITUTE SHEET (RULE 26)example , more than four independent cooling circuits inside the refrigeration unit in order to refrigerate larger places or more than one re frigeration unit installed in a single metallic frame to comply with the required cooling capacity or even more than one refrigerating unit installed in a symmetric or staggered disposition on the roof of the cold room .

[0066] Although the present invention has been described in relation to certain preferred embodiments , it should be understood that it is not intended to limit the invention to those particular embodiments . On the contrary, it is intended to cover all possible alternatives , modi fications and equivalences within the spirit and scope of the invention, as defined by the attached claims .SUBSTITUTE SHEET (RULE 26)

Claims

CLAIMS1 . Refrigeration unit with two re frigeration circuits , comprising a cold side 200 , a hot side 300 and an insulation 210 between said cold 200 and hot 300 sides ; wherein the cold side 200 includes : a structural support 220 disposed below the insulation 210 ; two evaporators 230 parallel to each other disposed on opposite sides of the structural support 220 ; two bulkheads 250A transversally disposed in relation to the evaporators 230 and each bulkhead 250A fixed to the ends of said evaporators 230 ; a partition 250B, said partition 250B disposed between and parallel to the two bulkheads 250A and between two cold side fans 260 , wherein said two cold side fans 260 are provided in two holes of an inferior plate 240 ; wherein the two evaporators 230 , the two bulkheads 250A, and the partition 250B are disposed below the structural support 220 ; and wherein the inferior plate 240 is provided below the two evaporators 230 , the two bulkheads 250A, and the partition 250B ; wherein the hot side 300 includes : a hot side base 301 disposed above the insulation 210 , said hot side base 301 supporting a first variable speed compressor 310A, a first inverter 320A, and a first thermostatic expansion valve 330A disposed in a first hot base side 301A;a second variable speed compressor 310B, a second inverter 320B, and a second thermostatic expansion valve 330B disposed in a second hot base side 301B ; and the hot side 300 further includes , in a third hot base side 301C, two water condensers 410 and balance valves 420 mounted to the water inlet / outlet of said water condensers 410 .2 . Refrigeration unit , according to claim 1 , wherein the first variable speed compressor 310A is provided between the first inverter 320A and the first thermostatic expansion valve 330A, and the second variable speed compressor 310B is provided between the second inverter 320B and the second thermostatic expansion valve 330B .3 . Refrigeration unit , according to claim 1 , wherein the hot side base 301 further supports a microcontroller 330 provided adj acent to the second inverter 320B .4 . Refrigeration unit , according to claim 1 , wherein the first hot base side 301A and the second hot base side 301B are parallel to each other .5 . Refrigeration unit , according to claim 1 , wherein the third hot base side 301C is between the first 301A and second 301B hot base sides .6 . Refrigeration unit , according to claim 1 , wherein the hot side 300 further comprises a first water pipe 430 and a second water pipe 431 mounted to the balance valves 420 , and a third water pipe 432 connected to a water supply .. Refrigeration unit with two re frigeration circuits , comprising a cold side 200 , a hot side 300 and an insulation 210 between said cold 200 and hot 300 sides ; wherein the cold side 200 includes : a structural support 220 disposed below the insulation 210 ; two evaporators 230 parallel to each other disposed on opposite sides of the structural support 220 ; two bulkheads 250A transversally disposed in relation to the evaporators 230 and each bulkhead 250A fixed to the ends of said evaporators 230 ; a partition 250B, said partition 250B disposed between and parallel to the two bulkheads 250A and between two cold side fans 260 , wherein said two cold side fans 260 are provided in two holes of an inferior plate 240 ; wherein the two evaporators 230 , the two bulkheads 250A, and the partition 250B are disposed below the structural support 220 ; and wherein the inferior plate 240 is provided below the two evaporators 230 , the two bulkheads 250A, and the partition 250B ; wherein the hot side 300 includes : a hot side base 301 disposed above the insulation 210 , said hot side base 301 supporting a first micro-channel condenser 510A and a first set of hot side fans 520A disposed in edge and between the first hot base side 301A and second hot base side 301B ;a second micro-channel condenser 510B and a second set of hot side fans 520B disposed in the edge and between the first hot base side 301A and the second hot base side 301B ; and wherein the first 520A and second 520B set of hot base fans are disposed in front of the first 510A and second 510B micro-channel condensers , respectively, with said first 520A and second 520B sets being closer to the center of the base 301 than the micro-channel condensers 510A, 510B .8 . Refrigeration unit , according to claim 7 , wherein the hot side base 301 further supports a first variable speed compressor 310A, a first inverter 320A, and a first thermostatic expansion valve 330A in the first hot base side 301A; and a second variable speed compressor 310B, a second inverter 320B, and a second thermostatic expansion valve 330B in a second hot base side 301B .9 . Refrigeration unit , according to claim 7 , wherein the first hot base side 301A and the second hot base side 301B are parallel to each other ;10 . Refrigeration unit , according to claim 7 , wherein the air flow coming from the first set of condenser fans 520A are separated from the air flow coming from the second set of condenser fans 520B by air flow deflectors 350A and B, respectively .11 . Refrigeration unit , according to claim 7 , wherein the fans of the first set of hot side fans 520A areprovided side by side , and the fans of the second set of hot side fans 520B are provided side by side .12 . Refrigeration unit , according to claim 7 , wherein the first 510A and second 510B micro-channel condensers are provided in the edge of the first 301A and second 301B hot base sides , respectively .13 . Refrigeration unit with four refrigeration circuits , comprising a cold side 200 , a hot side 300 and an insulation 210 between said cold 200 and hot 300 sides ; wherein the cold side 200 includes : a structural support 220 disposed below the insulation 210 ; four evaporators separated in two pair of evaporators 231 parallel to each other disposed on opposite sides of the structural support 220 ; two bulkheads 250A transversally disposed in relation to the two pair of evaporators 231 and each bulkhead 250A fixed to the ends of said two pair of evaporators 231 ; a partition 250B, said partition 250B disposed between and parallel to the two bulkheads 250A and between two cold side fans 260 , wherein said two cold side fans 260 are provided in two holes of an inferior plate 240 ; wherein the two pair of evaporators 231 , the two bulkheads 250A, and the partition 250B are disposed below the structural support 220 ; wherein the inferior plate is provided below the two pair of evaporators 231 , the two bulkheads 250A, and the partition 250B ; andwherein each of the four evaporators belongs to a each own refrigeration circuit comprising four refrigeration units in total ; wherein the hot side 300 includes : a hot side base 301 disposed above the insulation 210 , said hot side base 301 supporting a first 310A, a second 310B, a third 310C, and a fourth 310D variable speed compressor disposed side by side ; a first 320A, a second 320B, a third 320C, and a fourth 320D inverter disposed side by side ; wherein the the first inverter 320A is provided in front of the first compressor 310A, the second inverter 320B is provided in front of the second compressor 310B , the third inverter 320C is provided in front of the third compressor 310C, and the fourth inverter 320D is provided in front of the fourth compressor 310D; a first 330A, a second 330B, a third 330C, and a fourth 330D thermostatic expansion valve , wherein the first 330A and third 330C thermostatic valves are adj acent to each other and disposed in a first hot base side 301A, whereas the second 330B and fourth 330D thermostatic valves are adj acent to each other and disposed in a second hot base side 301B ; wherein the first 301A and second 301B hot base sides are parallel to each other ; wherein the hot side base 301 further supports a microcontroller 340 disposed in the vertex between the first hot base side 301A and a third hot base side 301C,wherein the second 301B and third 301C hot base sides are perpendicular to each other ; wherein the base 301 supports a fan 350 in the first hot base side 301A, said fan 350 provided between the microcontroller 340 and the third thermostatic expansion valve 330C ; wherein the hot side 300 further comprises , between the second 330B and fourth 330D thermostatic expansion valves and the microcontroller 340 , four water condensers 410 disposed parallel to each other .14 . Refrigeration unit , according to claim 13 , wherein the first and third compressors 310A and 310C and first and third inverters 320A and 320C are closer to a first hot base side 301A than the other compressors and inverters , and the second and fourth compressors 310B and 310D and second and fourth inverters 320B and 320D are closer to the second hot base side 301B than the other compressors and inverters .15 . Refrigeration unit with four refrigeration circuits , comprising a cold side 200 , a hot side 300 and an insulation 210 between said cold 200 and hot 300 sides ; wherein the cold side 200 includes : a structural support 220 disposed below the insulation 210 ; four evaporators separated in two pair of evaporators 231 parallel to each other disposed on opposite sides of the structural support 220 ;two bulkheads 250A transversally disposed in relation to the two pair of evaporators 231 and each bulkhead 250A fixed to the ends of said two pair of evaporators 231 ; a partition 250B, said partition 250B disposed between and parallel to the two bulkheads 250A and between two cold side fans 260 , wherein said two cold side fans 260 are provided in two holes of an inferior plate 240 ; wherein the two pair of evaporators 231 , the two bulkheads 250A, and the partition 250B are disposed below the structural support 220 ; wherein the inferior 240 plate is provided below the two pair of evaporators 231 , the two bulkheads 250A, and the partition 250B ; and wherein each of the four evaporators belongs to its own refrigeration circuit , comprising four refrigeration units in total ; wherein the hot side 300 includes : a hot side base 301 disposed above the insulation 210 , said hot side base 301 supporting a first 510A, a second 510B, a third 510C and a fourth 510D micro-channel condenser, wherein the first 510A and third 510C microchannel condensers are disposed side by side in a first hot base side 301A, and wherein the second 510B and fourth 510D micro-channel condensers are disposed side by side in the first hot base side 301A; a first 520A, a second 520B, a third 520C, and a fourth 520D hot side fan, wherein the first 520A and third 520C hot side fans are disposed parallel to each other in afirst hot base side 301A, and wherein the second 520B and fourth 520D hot side fans are disposed parallel to each other in the first hot base side 301A; wherein the first 520A, second 520B, third 520C, and fourth 520D hot side fans are disposed in front of the first 510A, second 510B, third 510C, and fourth 510D microchannel condensers , respectively, in a way the hot side fans are closer to center of the hot side base 301 than the micro-channel condensers ; wherein the hot side base 301 further supports a first 320A, a second 320B, a third 320C, and a fourth 320D inverter, wherein the first 320A and fourth 320D inverters are provided laterally to the first 310A and fourth 310D compressors in a first hot base side 301B, and wherein the second 320B and third 320C inverters are provided laterally to the second 310B and third 310C compressors in a first hot base side 301B ; wherein a second hot side base 301B further supports a first 310A, a second 310B, a third 310C, and a fourth 310D variable speed compressor provided in the center of said first hot side base 301A; and wherein the second 301B hot base sides is assembled above and in the center of the first 301A hot base sides .16 . Refrigeration unit , according to claim 15 , wherein the hot side base 301 further supports a first 330A, a second 330B, a third 330C, and a fourth 330D thermostatic expansion valves , wherein the first thermostatic expansion valve 330A is provided in the corner between the thirdcondenser 510C and third thermostatic expansion 330C, wherein the second thermostatic expansion valve 330B is provided in the corner between the fourth condenser 510D and the fourth thermostatic expansion valve 330D, wherein the third thermostatic expansion valve 330C is provided between the third inverter 320C and the first thermostatic expansion valve 330A, and wherein the fourth thermostatic expansion valve 330D is provided between the fourth inverter 320D and the second thermostatic expansion valve 330B .17 . Refrigeration unit , according to claim 13 or 15 , wherein each of the two pair of evaporators 231 comprises a first evaporator 231A with 4±0 . 5 fins per inch ( 6mm fins spacing) , and a second evaporator 231B with 6±0 . 5 fins per inch ( 4mm fin spacing) , wherein the first and second evaporators 231A, 231B are disposed parallel and contacting each other ; and wherein the fin density of the second evaporator 231B is from 22 % to 86% higher than the fin density of the first evaporator 231A.18 . Refrigeration unit , according to claim 13 or 15 , wherein the first evaporator 231A is fixed closer to the center of the refrigeration unit 100 than the second evaporator 231B .

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