EP2836779A2

EP2836779A2 - Hybrid refrigerator using two step cooling process

Info

Publication number: EP2836779A2
Application number: EP13734489.1A
Authority: EP
Inventors: Pradip SUBRAMANIAM; Girish Baluja; Tanmaya VATS; Ashish SOOD; Parikh DEWANG
Original assignee: Concentrate Manufacturing Company of Ireland
Current assignee: Concentrate Manufacturing Company of Ireland
Priority date: 2012-04-10
Filing date: 2013-04-10
Publication date: 2015-02-18
Also published as: RU2596138C2; WO2013153517A2; CN104395681A; WO2013153517A4; WO2013153517A3; RU2014145108A; CN104395681B

Abstract

A hybrid refrigeration system includes a first structure, configured to accommodate one or more containments. Further, the first structure has a first step cooling mode that is configured to pre-cool the containments, the pre-cooling being performed to reduce a temperature of the containments from a first temperature to a predetermined threshold temperature. Furthermore, the system also includes a second structure, also configured to house the containments. Herein, the second structure enables a second step cooling mode that further reduces the temperature of the containments from the predetermined threshold temperature to a final desired temperature.

Description

HYBRID REFRIGERATOR USING TWO STEP COOLING PROCESS

BACKGROUND

This invention relates generally to a cooling process, and, more particularly, to a cooling process carried out in two distinct steps.

The demand for beverage consumption in regions with high ambient temperatures is high. Correspondingly, demand for chilled beverages in such regions remains favorable as well. Current refrigeration/cooling processes and particularly, the widely used beverage coolers, housing beverages, employ a conventionally known single step cooling process that operate upon hermetically sealed compressor based on vapor compression cycle refrigeration systems. Such single step cooling process, when applied in conditions of high ambient temperatures, result in high energy consumption rates accompanied with requirements of high cooling capacity. As an example, in tropical regions where ambient temperatures during summers are high, high energy consumption, enabled through an equivalently sized cooling engine, remains the norm in cooling processes, to attain the desired temperature for beverages. In particular, cooling engines employed within cooling systems working under such high ambient temperatures, are required to perform heavy work to pull down beverage temperatures exemplarily ranging from as high as 41°C to 46°C, to a minimum range of 6°C to 4°C, causing an undesirable and high energy consumption rate. In addition, the temperature change obtained is at slow pace as well.

The need to employ small beverage coolers has thus been understood over the years to enable a more efficient cooling process. Even more so, such conventionally employed beverage coolers, being small in size, however, include hermetically sealed compressors, such as mentioned above, which do not provide commensurate cost benefits even with a reduction in cooler size or capacity. Moreover, for bringing down temperatures to a desired state, the stated compressors have fixed electrical and mechanical losses as well, causing the cooling systems to attain a low Co-efficient of Performance (COP) during operations under high ambient temperatures. Accordingly, with high running and operational costs, it is desirable to have a cooling unit that can work under high ambient temperatures, having a more energy and time efficient cooling process than the conventionally applied cooling processes.

SUMMARY One embodiment of the present disclosure describes a hybrid refrigeration system that comprising a first structure, which is configured to accommodate one or more containments. Further, the first structure comprises a first step cooling mode, operating through a first working mode. As stated, the first step cooling mode is configured to pre- cool the containments, the pre-cooling being performed to reduce a temperature of the containments from a first temperature to a predetermined threshold temperature. Furthermore, hybrid refrigeration system includes a second structure, configured to house the containments once the containments are sensed to have reached the predetermined threshold temperature. In particular, the second structure comprises a second step cooling mode, operating through a second working mode. More so, the second step cooling mode configured to further reduce the temperature of the containments from the predetermined threshold temperature to a final desired temperature.

Another embodiment of the present disclosure describes a two step cooling system that comprises a first structure, which is configured to accommodate one or more beverage containments. The first structure comprises a first step cooling mode that operates through a first working mode. In particular, the first step cooling mode is configured to pre-cool the containments, to reduce a temperature of the containments from a first temperature to a predetermined threshold temperature. Correspondingly, a second structure is disposed, which is configured to house the beverage containments once the containments are sensed to have reached the predetermined threshold temperature. More particularly, the second structure includes a second step cooling mode that operates through a second working mode. Herein, the second step cooling mode is configured to further reduce the temperature of the containments from the predetermined threshold temperature to a final desired temperature. In addition, a chill retention mechanism configured to retain a temperature within the second structure is enabled through a phase change material. Furthermore, a controller is disposed to indicate a completion of the first step cooling mode when the temperature of the beverage containments is sensed, through a temperature sensor, to have reached the predetermined threshold temperature.

Certain embodiments of the present disclosure describe a method of cooling in a cooling unit. Accordingly, the cooling unit includes a first structure, a second structure, with both the first structure and the second structure configured to accommodate one or more containments. A temperature sensor is configured on both the first structure and the second structure, configured to sense a temperature of the containments. In particular, the method comprises cooling the containments as part of a first step cooling mode in the first structure, through a first working mode. Herein, the cooling is configured to reduce first temperature of the containments to a predetermined threshold temperature. Further stages in the method include sensing the predetermined threshold temperature of the containments through either of the temperature sensors, and subsequently transferring the containments from the first structure to the second structure when the temperature is sensed to have reached the predetermined threshold temperature. Finally, cooling the containments as part of a second step cooling mode in the second structure, through a second working mode, reducing the temperature of the containments from the predetermined threshold temperature to a final desired temperature is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures described below set out and illustrate a number of exemplary embodiments of the disclosure. Throughout the drawings, like reference numerals refer to identical or functionally similar elements. The drawings are illustrative in nature and are not drawn to scale.

FIG. 1 is a schematic depicting a conventional single step cooling process alongside a two step cooling process of the present disclosure. FIG. 2 is a schematic of an exemplary pre-cooling system, according to the present disclosure.

FIG. 3 illustrates an exemplary application of the pre-cooling system of FIG. 2 combined with a conventionally known cooling system. FIG. 4A illustrates an active evaporative cooling system, according to embodiments of the present disclosure.

FIG. 4B illustrates a passive evaporative cooling system, according to embodiments of the present disclosure. FIG. 5 illustrates a psychrometric chart, according to the embodiments of the present disclosure.

DETAILED DESCRIPTION

The following detailed description is made with reference to the figures. Exemplary embodiments are described to illustrate the subject matter of the disclosure, not to limit its scope, which is defined by the appended claims.

Overview

In general, the present disclosure describes methods and systems for cooling beverages containments in two distinct steps. To this end, the containments are first maintained in a first structure, configured to be pre-cooled, through a known process, to a certain temperature, the pre-cooled temperature being considerably lower than the ambient temperature. Subsequently, when the temperatures of the beverages reach a predetermined threshold temperature, for example, a wet bulb temperature, the beverage containments are transferred to a second structure for a final cooling process. Eventually, by being in the second structure, the temperature of the beverage containments would lower down to a desired temperature more efficiently, to be suitable for consumption.

Exemplary embodiments

Certain principles of refrigeration or cooling, as known in the art, allows for a reduced energy consumption rate when an article/item that needs to be cooled is introduced into a cooling unit at a lower temperature, than when the article, at a higher ambient temperature, is introduced into similar cooling units. Beverage coolers, employed in regions having high ambient temperatures, and consequently suffering from high energy consumption rates may prove inappropriate at most occasions. This disclosure discusses a solution aiming to reduce high energy consumption, particularly in, though not limited to, beverage coolers, through a hybrid or a two step cooling process or mode, incorporated into regular refrigeration/cooling cycles. Correspondingly, it is understood that a first step cooling mode is operated through a first working mode, while a second step cooling mode is operated through a second working mode. Such working modes are discussed further. It is understood that temperature values, values of Co-efficient of Performance (COP), and other numerical values, disclosed and discussed all throughout the disclosure are exemplary in nature, and do not limit the aspects of the disclosure in any way.

FIG. 1 depicts a relational aspect between a conventional single step cooling process 102 and a two step cooling process 104, according to the present disclosure. In either case, it is known that the ambient working temperatures may remain in an exemplary range of 41°C to 46°C. With the conventional single step cooling process 102, a product, namely a beverage containment, may be cooled by employing a known cooling technique from an exemplarily temperature region ranging from 41°C to 46°C to another exemplarily temperature region ranging from 6°C to 4°C, accompanied by high energy consumption. Upon the adoption of the two step cooling process 104, a considerable reduction in energy consumption is observed. In particular, the two step cooling process 104 uses an efficient cooling method where the COP of evaporative cooling is observed to be much higher than conventional vapour compression cooling cycles. Such is enabled when the temperature of the beverage containment, brought from an ambient temperature, for example, ranging from 41°C to 46°C, is lowered to a temperature region around an exemplary wet bulb temperature (WBT) ranging from 23 °C to 28°C as an initial cooling process, referred to as a pre-cooling step, and is then transferred to a quick chilling chamber that functions to further reduce the temperature of the beverage containment from the range of 23°C to 28°C to a range of 6°C to 4°C. It is well known that the wet bulb temperatures may depend upon the relative humidity (RH) of a particular region and may thus vary from the temperature values depicted above. Further details and embodiments of the above mentioned two step cooling process 104 are discussed in the forthcoming disclosure.

Accordingly, FIG. 2 illustrates an exemplary pre-cooling system 200 configured to bring down temperatures of the articles/items placed within the system 200 from an ambient temperature, ranging exemplarily from 41°C to 46°C, to a relatively lower temperature, also ranging exemplarily from 28°C to 23°C. Such cooling is performed as a first step cooling mode. In particular, the embodiment of the pre-cooling system 200, illustrated in the figure, is enabled through either an active or a passive evaporative cooling system (discussed later). Further, the system 200 includes a cooler body 201 which is further configured to include a first structure 202, where the first structure 202 is configured to include or hold a cooling load, such a cooling load exemplarily being containments, referred to as beverages 224, disposed over a tray 204, as shown. The tray 204 provides accommodation not just to the beverages 224, but other articles/items, if any, configured to be cooled, as well. Further, the tray 204 includes apertures 203 that function to allow an amount of air to pass through or across the tray 204 as shown through an arrow B. It is understood that the beverages 224 are exemplary contents placed within a hot side region 222, and thus the hot side region 222 can include other articles and/or items that need cooling according to the present disclosure. In general, it can be further understood that the hot side region 222 will remain hot only at the beginning of the cooling process, and as and when the process enables the beverages 224 to reduce in temperature, the hot side region 222 will become cooler. For ease in understanding, the terminology applied for the hot side region 222 will however remain the same all throughout the present application. Furthermore, the system 200 includes a fan 210, operated electrically and functioning through a set of wiring 214 that runs an electric supply all through the whole system 200. A control panel 212 provides a mode for electrical connections and corresponding electrical operations.

It is understood that the active and the passive evaporative cooling processes or systems, as noted above, can have several other alternatives that can enable the beverages to attain a pre-cooled temperature. Such alternatives are discussed later in the disclosure. For ease of understanding, however, the working of the depicted embodiments in FIG. 2 and in FIG. 3 are discussed through active and passive evaporative cooling methods, as illustrated in FIG. 4A and FIG. 4B, respectively. Moreover, it is understood that these methodologies do not limit the aspects of the disclosure in any way.

As stated earlier, the fan 210 is configured to direct outside air into the system 200, with the direction of the flow of air being shown through the arrow A. More particularly, beyond the fan 210, the air is further diverted to the internally disposed hot side region 222 in the direction of the arrow B, as depicted in the figure. The flow and movement of air has been disclosed later in the disclosure.

Furthermore, the incoming air is made to pass through an evaporative pad 208 before entering the hot side region 222. The evaporative pad 208 may differ for active and passive evaporative cooling processes (described below). For ease of understanding, the embodiment depicted in FIG. 2 includes provisions for an active evaporative cooling process only. It can be understood that an overall working of the system 200 will remain similar when either of the cooling methods are applied.

Accordingly, for the active evaporative cooling process, the evaporative pad 208 may differ in structure from an absorbent pad 208' (shown in FIG. 4B) applied for the passive evaporative cooling. The pad 208 thus may have a cuboidal structure, enabling the pad 208 to fit within an available space within the system 200. The openings or pores employed in such pads can be larger than the ones employed for passive evaporative cooling, allowing more quantities of air to flow past the pad 208, during an operation. Hydrophobic coatings can be applied over the pad 208 to make the pad 208 water repellent, and also to inhibit bacterial and fungal growth. The structure, material, designs and manufacturing techniques for the pad 208 are well known to the skilled in the art and will not be discussed further. In particular, for evaporative based cooling, along with the evaporative pad 208, an arrangement of a water pump 213, a sump 207, containing water 209, and an air distributor tray 206, can be configured as shown in the FIG. 2. The air distributor tray 206 includes provision such as openings or apertures 203, similar to the ones disclosed for the tray 204, that help directing of an incoming air towards the beverages 224 in a uniform fashion. In particular, the air distributor tray 206 includes a portion including several predefined apertures 203 that primarily functions to provide provisions to distribute an incoming air uniformly, as shown through the arrow B, towards the beverages 224. More so, an arrow 211 depicts a flow of water 209 reaching to the top of the evaporative pad 208, as shown, and being sprinkled such that the evaporative pad 208 becomes adequately drenched in the water 209. Certain embodiments may include fluids other than the water 209 as well. On the other hand, the passive evaporative cooling process can include the pad 208', the pad 208' being configured to be flexible like cloth, and can further be configured to include open micro pores that absorb water, or any other liquid that the pad 208' has been placed in contact with. Further, the pores are sized such that when the fan 210 is operated, a quantity of air is blown through, across, or over, the pad 208', consequently lowering the temperature of the beverages 224 placed within the hot side region 222. The sizing of the micro porous structure can allow water or any applied liquid to be absorbed and retained within the pad 208' for a considerably long period as well.

In an embodiment, one side of the pad 208' being disposed towards an outside environment 150, as shown in the figure, allows provision for a company name, logo, etc., to be disposed on the outer facing portion, and accordingly, the outer facing portion can be made water repellent as well. Accordingly, the pad 208' can be treated through known agents before being applied, such as being hydrophobically coated, for inhibiting bacterial and fungal growth over long periods of application. Such coatings, however, may be understood to be applied on a single side of the pad 208', over a limited surface area so that the coating does not block a flow of air, while correspondingly allowing the company name, logo, etc., to be visibly disposed over the limited surface area. The structure, material, designs, and ways to manufacture such kind of pads are well known to the skilled in the art and thus will not be discussed further. In contrast to the arrangements for the active evaporative cooling, arrangements within the passive evaporative cooling can include the placement of the pad 208' to be similar to the placement in the active evaporative cooling, however enabling the fan 210 to be optionally removed. Further, the sump 207 can be included with the pad 208' being placed directly above the sump 207 in contact with the water 209. Such related arrangements and configurations of the pad 208' are described in further detail for the description for FIG. 4B.

In particular, the pads 208 and 208' applied for both passive and active evaporative cooling methods can be configured through a removable cartridge 215. Accordingly, such removable functionalities of the cartridge 215 can enable a user to replace one for the other, depending upon consumption limitations and capacity needs. Also such cartridges can enable replacement of a worn out pad with ease. More so, with an active evaporative cooling consuming more energy than a passive evaporative cooling, the cooling performance is faster in the active evaporative cooling than the passive evaporative cooling processes. As an example, in regions where the provisions of a pump and a fan are not available, passive evaporative cooling can be employed to lower temperatures of a cooling load comprising exemplarily the beverages 224. Such a change in application becomes easier when pads 208 and 208' are interchangeable through the removable the cartridge 215.

In addition to the components described above, the system 200 includes a controller 218, connected to the fan 210, a temperature sensor 220, and a feedback interface 226, both being connected to the controller 218 as well. Such an arrangement is shown and can be understood through FIG. 2. In particular, the temperature sensor 220 is configured to sense the temperature of the hot side region 222, whereas, the feedback interface 226 is configured to provide a corresponding temperature related information to a user (not shown), disposed external to the system 200. Certain embodiments can include the measures of time related information to also be provided through the feedback interface 226 to a user.

In detail, the first structure 202 can be an enclosure, big enough to accommodate one or more beverages 224 in the form of cans, bottles, etc., within the system 200. The first structure 202 can be made from known materials, like metallic and non-metallic substances, and can include adequate heat insulation properties, if configured to form an enclosure, keeping the contents within the first structure 202 protected from high outside temperatures. Moreover, configurations, dimensions, manufacturing, and fabrication techniques, of the first structure 202 are well known to the skilled in the art and thus will not be discussed further. In particular, the first structure 202 can be configured either as an open structure, a partially open structure, or as a closed structure, depending upon the ambient conditions and desired requirements.

The temperature sensor 220 can be a simple temperature based sensor that senses temperatures of the hot side region 222 and can be similar to any of the widely applied temperature sensors in the market. More particularly, the temperature sensor 220 is connected to the controller 218, as shown, and allows the controller 218 to record all sensed temperature related information in a memory 216. In certain embodiments, the temperature sensor 220 can be based on a thermistor.

The controller 218 forms one part of the hardware of the system 200, as depicted. As is known, the controller 218 can either be an electromechanical control unit or microprocessor based device. Accordingly, a microprocessor based device can include a CPU (not shown), enabled to process the incoming information from a known source, the known source, being more than one in this case, includes the fan 210 and the temperature sensor 220. Further, the controller 218 may be incorporated with volatile memory units, such as a RAM and/or ROM that function along with associated input and output buses. The controller 218 may also be optionally configured as an application specific integrated circuit, or may be formed through other logic devices that are well known to the skilled in the art. More particularly, the controller 218 may either be formed as a portion of an externally applied electronic control unit, or may be configured as a stand-alone entity. With certain portions of the controller 218 being connected to the fan 210 and the temperature sensor 220, the feedback interface 226 is connected as well to the controller 218, enabling an output to be visible or audible to a user, external to the system 200. Moreover, signals received from the temperature sensor 220 are configured to be stored in the memory 216 and processed further through the CPU, all being configured within the controller 218. Furthermore, the controller 218 can be configured to include a timer device (not shown) that can record time based information, which can enable the controller 218 to effectively receive both temperature and time related data. Time and temperature relationships can subsequently be obtained through appropriate calculation methodologies stored within the controller 218, and can accordingly allow a user to analyse temperature of the hot side region 222, even when the temperature sensor 220 is switched off or not available. Alternatively, the timer can be switched off as well, and information obtained from the temperature sensor 220 alone can be utilized to analyze the temperature attained within the hot side region 222, irrespective of the time taken.

The memory 216, disposed within the controller 218, can include volatile and non- volatile storage regions that store information related to the overall functioning of the system 200. More particularly, the memory 216 may thus record information related to the sensed temperature existing within the hot side region 222, along with storing the tracked time, the tracking being performed through the timer (not shown). Further, the memory 216 can also be configured to include predetermined functional values, sensor related information, and particularly WBT values, related and derived from a sensed relative humidity (RH), the sensing being performed through a RH sensor (not shown). Further, other temperature related values, such as predetermined threshold temperature values, maximum and minimum workable temperatures for the components of the system 200, one or more algorithms to process incoming temperature signals, and time related information. Also, the memory 216 can include information based on operational features of the fan 210 and the pump 213, for example, at what attained temperature of the beverages 224 the fan 210 and/or the pump needs to be activated or deactivated, etc. Furthermore, certain calculation methodologies, display and graphics information, maximum and minimum battery life (if included), other specifications of the system 200, memory 216, controller 218, etc., can be included in the memory 216 as well.

Certain algorithms based on calculation methodologies can be added to the controller 218 as well that can assist in processing incoming temperature signals from the temperature sensor 220. In addition, for deriving a WBT, the algorithm can include calculation method to enable derivation of the WBT, which can be the predetermined temperature threshold in cases of active and passive evaporative cooling processes during a first step cooling mode or a pre-cooling application, such as enabled through the system 200. More so, the mentioned predetermined threshold temperature values can be set when the first step cooling mode (pre-cooling process) is being performed through other methods as well, such as through a phase change material (PCM), cooling through dual evaporators, thermoelectric cooling, geothermal cooling, and cooling through an air conditioned duct. Furthermore, all such first stage cooling methods have been discussed later. During operation, the system 200 can be configured as a stand-alone unit, configured to lower temperatures of the beverages 224 housed within the first structure 202. In particular, beverages 224, when brought from the outside environment 150, would have temperatures related to the outside environment 150, or, more often, the beverages 224 would possess temperatures similar to an ambient temperature. With the application of the system 200, the beverages 224 can be placed within the first structure 202 as shown in FIG. 2. An optionally positioned switch, such as the switch 228, can be employed to allow activation and deactivation of the system 200 when required.

Upon the activation of the first step cooling mode, the fan 210 rotates and pushes outside air into the system 200 as shown. The pushed air, flowing across the evaporative pad 208, shown through the arrows A, flows across the pad 208. Water or an equivalent liquid, maintained in an absorbed state in the pad 208, allows the temperature of the air flowing through to decrease, enabling a cooler air to flow past the pad 208, and flow towards the sump 207, as shown. Further, the fan 210, through constant operation pushes the cooled air into the hot side region 222. As shown through the arrows in the figure, the incoming air is directed towards the sump 207, after an entrance, and is further directed towards the beverages 224, as shown. The flow of air, as shown, enables a uniform distribution of air throughout the hot side region 222. The air distributor tray 206, upon which the beverages 224 are accommodated, aids in such uniform distribution of air. The cooler air, subsequently, interacts with the beverages 224 and the articles/items placed within the first structure 202 and pre-cools them through forced convection, enabling to lower the temperatures from a first temperature to a predetermined threshold temperature. Moreover, the incoming air, shown through the arrow B passes through the beverages 224 cooling them and subsequently venting out of the hot side region 222 through an exhaust 230, as depicted. Certain embodiments may include the exhausted air to be further utilized since the exhausted air is at a lower temperature than a surrounding ambient temperature. Accordingly, as an example, the air can be delivered to an ambient having a higher temperature consequently cooling the ambient and providing occupants of the ambient, if any, with an amount of air having more comfortable temperature in a high ambient temperature. Further examples can include, the exhaust 230 to be used to cool a condenser, working with a R134A refrigerant and employed in a cooling unit. Accordingly, conventional condensers, maintained at 54°C Medium Back Pressure (MBP), at 41°C ambient temperature, can be maintained at even lower temperatures, thereby, improving the COP and capacity of the condenser. Furthermore, the utility of such an exhausted air can be beyond the above disclosed examples, and the ones skilled in the art will have the knowhow of how such a low temperature air can be utilized further. Once a minimum temperature, (which in passive and active evaporative cooling can be a WBT) relative to the predetermined threshold temperature, is achieved in the hot side region 222, the temperature sensor 220 senses the prevailing temperature within the first structure 202 and outputs a corresponding temperature signal to the controller 218. The controller 218 accordingly functions to convert the signals into a compatible format, and compares the sensed and converted signal of the temperature to a predetermined temperature value. The controller 218 correspondingly determines whether a predetermined minimum or a threshold temperature has been achieved or not. If the predetermined temperature is achieved, the controller 218 sends a related signal to the feedback interface 226, enabling a feedback to be provided to a user, disposed exterior to the system 200, allowing the user to know that a predetermined temperature has been attained. The user can accordingly deactivate the system 200 and remove or transfer the beverages 224 and other articles/items from the first structure 202 to be further housed within other systems for a second step or a final chilling or cooling process. It will be understood that through such a pre-cooling system, lowering temperatures of the beverages 224 and other articles/items improve while helping to limit the system's overall energy consumption. The above methodology accordingly when applied enables a two step cooling process to be incorporated for systems, enabling an energy efficient mode of cooling.

In certain embodiments, automatic deactivations of the pre-cooling system 200 can be configured and a corresponding feedback through a visual, audible, etc., can be provided, encouraging a user to carry on with a further cooling process. It is understood that such automatic deactivations would be accompanied by an automatic reactivation, as well, when the temperature of the beverages 224 is sensed to have increased beyond the predetermined temperature threshold.

In further embodiments, two step cooling processes can include an integral or combined pre-cooling system with final cooling or chilling stations that would improve upon usability and convenience for a user. Accordingly, FIG. 3 depicts a cooling system 300 employing the pre-cooling system 200 combined with a second structure namely, a quick chilling station 302 as part of a second step cooling mode, as shown. The principle of refrigeration/cooling, and, more particularly, the second step cooling mode or process, as depicted in the figure, is based on thermoelectric (TEC) cooling. It is understood that TEC cooling is not the only way to attain a cooling of the beverages 224 to an exemplary temperature region around 4°C to 6°C, and rather multiple other ways can be applied to enable a similar second step cooling mode. Such cooling modes have been described later in the disclosure.

Accordingly, thermoelectric cooling, as depicted in the figure, is a way to remove thermal energy from a medium, device or component by applying a voltage of a given polarity to a junction between dissimilar electrical conductors or semiconductors, which is to typically generate cold within an enclosure and heat outside the enclosure. Such cooling is observed to be particularly energy efficient when the temperature difference (dT) between the hot side and the cold side is relatively low at exemplarily around 15°C, and not as energy efficient when the dT between the cold side and the hot side is at exemplarily around 40°C. The hot side region 222 and a cold side region 310, thus, respectively, employ an arrangement as shown in the figure. The arrangement accordingly employs a TEC cold side 308 and a TEC hot side 306, as shown. When an electric potential, of a known and required value, is applied at a junction of the TEC hot side 306 and the TEC cold side 308, cooling is observed and attained at the cold side region 310.

The working of the pre-cooling system of the cooling system 300, being identical to the one described for the pre-cooling system 200, thus combines with the quick chilling station 302 to enhance beverage cooling application and usability. It will be understood that the embodiments described for the pre-cooling system 200, are equally applicable for the cooling system 300, as well.

During an operation, a feedback obtained at the feedback interface 226, through the controller 218, depicting a predetermined threshold temperature reached by the pre- cooling system 200 for the beverages 224, indicates the completion of the first step cooling mode, and allows a user to remove the beverages 224 and/or articles/items for consumption from the first structure 202, and place them in the quick chilling station 302. In particular, the temperature sensor 220, sensing the temperature within the first structure 202, can also be configured to sense the temperature within the quick chilling station 302 as well. Certain embodiments can however include another temperature sensor 304, similar to the temperature sensor 220 placed within the confines of the quick chilling station 302, as shown, to sense the temperature within the quick chilling station 302. Accordingly, when corresponding temperature values are sensed through either of these arrangements, related signals are provided to the controller 218 for processing, and finally the processed signals are provided to the user, disposed exterior to the cooling system 300. The cooling load being smaller, since a pre-cooling is already achieved, enables the quick chilling station 302 to quicken cooling, facilitating the temperature of the beverages 224, and other articles/items housed within the quick chilling station 302 to lower down to a desirable range suitable for consumption in a lesser period. Such temperatures can exemplarily range from 6°C to 4°C. In particular, the incoming air shown through the arrow B flows across the beverages 224 lowering the beverage temperatures. Before reaching and being vented through the exhaust 230, however, the incoming air is made to pass through a passage 232 as shown, enabling the air to be received and interact with the TEC hot side 306, and consequently lowering the temperature of the TEC hot side 306. With the cooling of the second step cooling process being performed through thermoelectric cooling, the lowering of the TEC hot side 306 enables the dT between the TEC hot side 306 and TEC cold side 308 to reduce as well, allowing the thermoelectric cooling mode to function even more efficiently. Certain embodiments can enable the controller 218 to incorporate provisions and calculation methodologies, as noted above, to calculate time and temperature related information that can assist users in perceiving a temperature value of the beverages 224, even when the temperature sensors 220 and 304 are not available or are deactivated. In such cases, it will be known that time, recorded through a timer, can assist users in determining an approximate beverage temperature value, provided other functionalities of the system 300, run according to set standards.

In particular, it is understood that the configurations described in FIG. 3 for the cooling system 300 are not limiting in any way. Accordingly, the two step cooling functions can work completely independent of each other as well. Structurally too, the first step cooling mode, comprising the pre-cooling system 200, and the second step cooling mode, comprising the quick chilling station 302, can be configured apart from each other, and can thus be applied depending upon ambient temperatures and other conditions prevailing at an user end.

Furthermore, the flexibility in enabling the first and the second step cooling modes separately also helps the first and the second step cooling modes to function through different sources of energy, as well. Such can be the case even when structurally the two cooling modes are integrated into a common unit. This, however, may not be the case at all times. In addition, even when the two cooling modes are separated, interconnections can be made possible to develop interactions between the first step and the second step cooling modes, enabling an efficient cooling process. Active and passive evaporative cooling functions, being possible pre-cooling functions have been described in detail. It is understood that for pre-cooling functions, such as the ones employed in the pre-cooling system 200 or the cooling system 300, an active or passive evaporative cooling are not the only way of attaining pre-cooled beverages 224. Alternatively, several other procedures can be incorporated.

Concepts of active and passive pre-cooling systems, thus, can be understood through the FIG. 4A and FIG. 4B, respectively.

Accordingly, FIG. 4A depicts an active evaporative cooling system 400a that can function as one of the pre-cooling methodologies employed within either of the systems 200 and 300. Further, the active evaporative cooling 400a includes the evaporative pad 208, as described before, to be disposed as shown in FIG. 4A. In particular, this method of pre- cooling includes the sump 207, water pump 213, configured to pump the water 209 stored in the sump 207 through a piping 402, as shown. Moreover, the piping 402 is configured to supply water through a water distributor 404 over the evaporative pad 208, as depicted, developing a wetted evaporative pad 208. In particular, the structure and functioning of the arrow 211, depicted in FIG. 2, is understood through the arrangement of the piping 402 and water distributor 404.

During operation, the pump 213 pumps the water 209, stored in the sump 207, through the piping 402 and supplies the water 209 over the evaporative pad 208, as shown. Water 209 captured in the pores or opening of the evaporative pad 208 allows air passing over or across the pad 208, the passage enabled through the fan 210, to be cooled down to a lower temperature, further enabling the beverages 224, over which the cooled air flows over, to drop in temperature from the first temperature to a predetermined threshold temperature. The water 209, entering the evaporative pad 208, drains back into the sump 207 through holes or openings (not shown) configured at the bottom of the pad 208, the draining forming a water circulation circuit. As disclosed above, air entering through the pad 208, shown through the arrow A, and assisted through the fan 210, cools down in temperature when it passes through the pad 208. This cooled down air is shown through the arrow A'. Such cooling of the air further enables a drop in the temperature of the hot side region 222, as well as reducing the temperatures of any cooling load in the form of beverages, articles, etc., disposed within the first structure 202. Likewise, passive evaporative cooling can function as an alternative to active evaporative cooling, as described above, enabling the system 200 to incorporate pre-cooling functions similar to the ones described above.

Accordingly, FIG. 4B depicts an exemplary passive evaporative cooling system 400b. The structure, components and working remaining the same for the system 400b, is different minimally from the system 400a. Such difference primarily includes the fan 210 as an option, and an alternate way of wetting the pad 208'. Particularly, the fan 210 can be completely avoided for such a configurations and air can be brought into the hot side region 222 through a natural convection process. Further, the pad 208' incorporates multitude of holes, making the pad 208' open and micro porous in structure, enabling the absorbing of water 209 through a capillary action. Accordingly, as shown the system 400b may not include a water pump or a fan, like the ones discussed for the system 400a, but may include the sump 207 and a water distributor 404', similar to the one already disclosed. Further, the system 400b includes an accumulator 408 configured to accumulate water, as shown, and a piping 410, connecting the sump 207 to the accumulator 408.

During an operation of the passive evaporative cooling system 400b, water 209, stored in the accumulator 408, includes a pressure head. Accordingly, the water 209 travels, as shown through the arrow E, into the water distributor 404', through the piping 402' because of a pressure head maintained in the accumulator 408, and subsequently distributes over the pad 208', as shown in the figure. The distribution of the water 209 is similar to the one discussed in connection with the FIG. 4A. The absorbent pad 208' absorbs the water 209 and distributes the water 209 through a capillary action all throughout the surface of the pad 208'. The water 209 flowing into the pad 208' further flows down into the sump 207 through holes or openings configured in the pad 208', from where the water 209 is directed back into the accumulator 408 through the piping 410, the piping 410 configured to include a check valve 406 that allows a unidirectional flow of water 209 such that the water 209 stored in the accumulator 408, does not enter the sump 207, but rather the water 209 flows only from the sump 207 to the accumulator 408, as shown through the arrow D. It will be understood that any passage of air through the pad 208' is enabled through a natural convection process. Accordingly, when a quantity of air enters the pad 208', shown through the arrow A, cools down to a quantity of air having a lower temperature, shown through the arrow A'. Furthermore, the cooling of a cooling load such as the beverages 224 can be understood to be similar to the process discussed in relation with FIG. 4A. Other embodiments and working requirements of such a system are known to the skilled in the art and thus will not be discussed further. In an embodiment, water 209 can be replaced with equivalent fluids that can help in lowering temperatures of the beverages 224. In particular, fluids that can replace water 209 may have properties, such as surface tension, viscosity, etc., similar or better to that of water, and that may enable them to be pumped, distributed like water during the pre- cooling function. Such fluids are well known to the skilled in the art and thus the related aspects will not be discussed further.

The aspects of the present disclosure can be understood through a psychrometric graph 500 as shown in FIG .5. The graph 500, being well known to the skilled in the art, depicts a dry bulb temperature (°C) on the X-axis, and a corresponding humidity ratio (lb/lb of dry air) on the Y-axis. In particular, the curve 502 can be under stood to be an exemplary WBT line of 15.5°C, curve 504 to be a curve depicting 80% relative humidity (RH), curve 506, the 100% saturation line, while curve 508 to be depicting 20%> RH. More so, the graph 500 is not drawn to scale.

Here, as shown by graph 500, the working concept of the above discussed pre-cooling methods, namely, active and passive evaporative cooling systems 400a and 400b, respectively, can be understood in further detail. It is also understood that the values of temperature, humidity ratio, etc., mentioned below are exemplary in nature, and may not be precise in relation to the actual values.

Accordingly, an amount of ambient air configured to be directed into the hot side region 222, can be at an exemplary dry bulb temperature of 30°C, having 20% (RH), and can have a corresponding WBT ranging around 15.5°C. The travel of air from the outside environment 150 to the hot side region 222 of the pre-cooling system 200, through the evaporative pad 208 or the absorbent pad 208' enables the air to drop in the dry bulb temperature exemplarily from 30°C to region around 18.3°C. Such a drop is made possible because the air, passing through the pads 208 and 208', becomes saturated as a result of the water content present in the pads 208 or 208'. Moreover, such a saturation level change can exemplarily range from the 20% RH of ambient air initially, up to 80% RH for the air when the air passes beyond the pads 208 or 208'. Subsequently, it can be seen from the graph 500 that a relative change in the moisture content of air or the relative humidity ratio of the air varies as well. Such variations also can exemplarily range from an initial value of around 0.00525 lb/lb to an eventual value of around 0.01070 lb/lb of dry air, as depicted. Accordingly it could be understood that an ambient air being directed inwards to the hot side region 222 would showcase a change in the dry bulb temperature, through a reduction in heat accompanied by a change in mass through an increase in the humidity ratio of the air.

As the disclosure discloses a cooling methodology being carried out in two distinct steps, it can be understood that applications, involving a pre-cooling function and a quick chilling function, can be carried out through multiple processes and may not be limited to the principles of active and passive evaporative processes alone. More so, the embodiments disclosed in the present application for pre-cooling and the quick chilling applications are not limiting in any way. Similar pre-cooling applications may thus be performed through multiple other ways as well. Accordingly five alternative pre-cooling processes have been discussed further in the forthcoming disclosure, in addition to the active and passive evaporative cooling systems 400a and 400b already discussed.

Accordingly, the alternatives for pre-cooling functions may include a thermoelectric cooling method similar to the one disclosed and applied for the TEC hot side 306 and TEC cold side 308 in the cooling system 300. Since thermoelectric cooling, involving minimal temperature differences between a hot side and a cold side proves beneficial for relatively limited energy consumption, cooling systems, like the system 300, can employ thermoelectric systems for a pre-cooling function. For example, when temperature differences between a hot side and a cold side is less than 15°C, COP (co-efficient of performance) can be as high as 2 to 2.5.

Other pre-cooling functions may include conventional refrigeration/cooling units with dual evaporators, wherein, the conventionally hermetically sealed compressors, of both types, namely AC and DC, can be used effectively for pre-cooling of beverages 224 by balancing the sealed system. The method of using dual evaporators in a refrigeration/cooling system is energy efficient because a COP obtained of Medium Back Pressure (MBP) refrigeration/cooling circuit, in lower size compressors, along with a COP obtained of High Back Pressure (HBP) refrigeration/cooling circuit, when combined together gives a higher overall COP, than when single evaporators are used. Such can, however, depend on the ratio of the dual evaporator sizing done for the pre cooling function & the quick chilling function. A phase change material may alternatively be employed to enable a pre-cooling application, such as the one discussed above. In regions where the night temperatures are considerably lower than the day temperatures for a substantial time, phase change materials can be employed to perform free-cooling. In free-cooling, phase change materials can store latent heat energy at night, accounting to a reduction in ambient temperatures during night time, by solidifying, and subsequently, releasing the energy during day time by melting at higher day time ambient temperatures. Such release of energy and a consequent melting is enabled through a transfer of heat from a cooling load such as the beverage 224 to the phase change material. In effect, the beverages 224 can be maintained at the same temperature, as the night ambient temperature, even during high ambient day time temperatures. Pre-cooling applications for beverages 224 can thus be employed with similar phase change materials that can absorb heat from the beverages during the day, thereby, reducing beverage temperatures, and releasing this thermal energy to an ambience maintained at lower temperatures at night.

Further embodiments can include certain natural free energy sources such as geothermal energy, night sky cooling, and zeolite based desiccant cooling, which does not require an external energy source and can thus be effective in consuming the least possible energy for pre-cooling applications. In particular, such applications being well known in the art will not be discussed further in the present disclosure.

In still other embodiments, a duct from an air conditioned environment, when directed towards a pre-cooling chamber such as the first structure 202, can help in lowering temperatures and provide cooling to the contents placed within the chamber. Such contents can be the beverages 224, as described above. In particular, air conditioned environments having temperature ranges of 27°C to 18°C, can help considerably in lowering temperatures of such contents that requires pre-cooling. The second step cooling mode, involving a final chilling or a cooling process, performed through the quick chilling station 302 can also be attained through multiple ways. The forthcoming disclosure describes three such ways. It will however be known that the second step cooling mode may incorporate a variety of conventionally known applications, and the ones described here, as distinct embodiments, are not limiting in any way. Accordingly, as noted for system 300, thermoelectric cooling may be incorporated to attain a final chilling process and such a process being disclosed already in the application will thus not be described further. As stated earlier, thermoelectric cooling mode, not being the sole option for the second step cooling mode for the final cooling process, allows alternative cooling modes to be incorporated as well. Such alternative cooling modes have been discussed below.

Accordingly, further embodiments of the second step cooling process may thus include conventional cooling processes such as the ones achieved through the incorporation of a DC micro/mini refrigeration based compressor. Such compressors, in particular, can be used for smaller size beverage coolers. This takes advantage from an eventual beverage temperature attained, as the beverage temperatures are already in a pre-cooled state, exemplarily ranging from 23 °C to 28°C, brought down through the pre-cooling system 200, when the second step cooling starts. This enables using a DC micro compressor of relatively a smaller capacity, which is energy efficient, being typically based on PMBLDC (Permanent Magnet Brushless Direct Current) which has minimal electrical losses. More so, DC compressors being based on motor & rotary compressor have lower mechanical losses as well.

Further, such compressors may enable the cooling performance to further improve even if the evaporating temperature is made higher from a -6.7 to 0°C. In such a condition, certain design interventions will be required to enable an availability of cooling loads, such as the beverages 224, at an exemplary chilling temperature range of 4°C to 6°C. Accordingly, a solution can involve the beverages 224 in the final chilling chamber to be directly cooled by an intimate contact of bottles with a roll bond type shaped evaporator, which is shaped accordingly, eliminating air and other media. Consequently, easier cooling to a desired temperature can be attained. Usage of a direct contact roll bond evaporator will therefore help in quicker chilling as it minimizes thermal losses associated with conventional air based cooling. In particular, it will be understood that the temperature of -6.7°C is a convention used for MBP cooling applications.

In yet other embodiments, AC compressors can be employed in place of DC micro/mini compressors. Certain measures can be employed to balance the refrigeration/cooling cycle evaporating temperatures to range exemplarily from 1°C to 0°C, which is higher than the conventional temperature of -6.7°C, employed for MBP cooling applications. Such measures can accordingly include the roll bond evaporators, similar to the one disclosed for DC micro/mini compressors that can be configured to directly cool the beverages or any applied cooling load. Accompanied by an improved COP, faster chilling of the beverages 224 can thus be enabled through such arrangement that lowers thermal losses.

Certain chill retention measures can be employed within the quick chilling station 302 either through the incorporation of adequate insulation materials enabling a protection from outside heat, or through phase change materials, which can be cooled and solidified during a normal working operation of the cooling unit. A consequent solidification and release of a corresponding thermal energy during day time, by the phase change material, gradually melting at higher ambient temperatures can allow minimum temperatures to be maintained even when power supply is not available. Appropriate regions for storage, transfer, and circulation, if any required, of the phase change material can be incorporated within the quick chilling station 302. Through such an arrangement, the temperatures within the quick chilling station 302 can be maintained, for example, below 10°C, or below any desired temperature. Further, it is understood that such minimum temperature requirements can become a factor for the type, volume, and other properties for the phase change material applied.

Furthermore, it can be understood through the above disclosure that seven distinct options for the pre-cooling process, forming a first working mode, and three distinct options for the final cooling processes, forming a second working mode, are available for enabling a two stage cooling process. Such processes when combined work out to reduce energy consumption in regions having high ambient temperature, for example above 41°C. Furthermore, any of the discussed seven pre-cooling process, on one hand, and either of the three final cooling processes, on the other hand, can be combined with each other making a total of twenty one distinct possible combinations for enabling a cooling process operating through two steps, through which the two step cooling process 104 can be carried out.

The specification has set out a number of specific exemplary embodiments, but those skilled in the art will understand that variations in these embodiments will naturally occur in the course of embodying the subject matter of the disclosure in specific implementations and environments. It will further be understood that such variation and others as well, fall within the scope of the disclosure. Neither those possible variations nor the specific examples set above are set out to limit the scope of the disclosure. Rather, the scope of claimed invention is defined solely by the claims set out below.

Claims

THE CLAIMS:

1. A hybrid refrigeration system comprising:

a first structure, configured to accommodate one or more containments, the first structure comprising:

a first step cooling mode, operating through a first working mode, the first step cooling mode configured to pre-cool the containments, the pre-cooling being performed to reduce a temperature of the containments from a first temperature to a predetermined threshold temperature; and

a second structure, configured to house the containments once the containments are sensed to have reached the predetermined threshold temperature, the second structure comprising:

a second step cooling mode, operating through a second working mode, the second step cooling mode configured to further reduce the temperature of the containments from the predetermined threshold temperature to a final desired temperature.

2. The system of claim 1, wherein the first step cooling mode, operating through the first working mode, is configured to be carried out through one of the following:

an active evaporative cooling process;

a passive evaporative cooling process;

a thermoelectric cooling;

a dual evaporator cooling;

a cooling through a phase change material;

a cooling through a natural free energy source; and

a cooling through a duct from an air conditioned environment.

3. The system of claim 2, wherein the active evaporative cooling process includes a combination of air, water, pump, and a evaporative pad to pre-cool the containments, the pump configured to supply water to the pad, the air configured to pass across the pad to reach the containments, lowering the first temperature to reach the predetermined threshold temperature, the evaporative pad configured to be applied and removed, within the cooling process, through a cartridge.

4. The system of claim 2, wherein the passive evaporative cooling process includes a combination of air, water, and an absorbent pad to pre-cool the containments, the absorbent pad to absorb water through capillary action, the air configured to pass across the pad to reach the containments, lowering the first temperature to the predetermined threshold temperature, the absorbent pad configured to be applied and removed, within the cooling process, through a cartridge.

5. The system of claim 2, wherein the second step cooling mode, operating through the second working mode, is configured to be carried out through one of the following: a thermoelectric cooling;

a DC micro/mini compressor; and

an AC compressor.

6. The system of claim 5, wherein a hot side of the thermoelectric cooling, when applied in the second step cooling mode, is configured to receive air, enabling a lowering of a temperature of the hot side, the air being received through the active evaporative cooling process.

7. The system of claim 1, wherein the second structure includes a chill retention mechanism, enabled through a phase change material, the mechanism configured to retain a temperature within the second structure.

8. The system of claim 1 further comprising a controller configured to indicate a completion of the first step cooling mode when the temperature of the containments is sensed to have reached the predetermined threshold temperature, the sensing being performed through a temperature sensor.

9. A two step cooling system comprising:

a first structure, configured to accommodate one or more beverage containments, the first structure comprising:

a first step cooling mode, operating through a first working mode, the first step cooling mode configured to pre-cool the containments, the pre- cooling being performed to reduce a temperature of the containments from a first temperature to a predetermined threshold temperature;

a second structure, configured to house the beverage containments once the containments are sensed to have reached the predetermined threshold temperature, the second structure comprising:

a chill retention mechanism configured to retain a temperature within the second structure, the mechanism enabled through a phase change material; and

a controller configured to indicate a completion of the first step cooling mode when the temperature of the beverage containments is sensed, through a temperature sensor, to have reached the predetermined threshold temperature.

10. The system of claim 9, wherein the first step cooling mode, operating through the first working mode, is configured to be carried out through one of the following:

an active evaporative cooling process;

a passive evaporative cooling process;

a thermoelectric cooling;

a dual evaporator cooling;

a cooling through a phase change material;

a cooling through a natural free energy source; and

a cooling through a duct from an air conditioned environment.

11. The system of claim 10, wherein the active evaporative cooling process includes a combination of air, water, pump, and a evaporative pad to pre-cool the beverage containments, the pump configured to supply water to the pad, the air configured to pass across the pad to reach the beverage containments, lowering the first temperature to the predetermined threshold temperature, the evaporative pad configured to be applied and removed, within the cooling process, through a cartridge.

12. The system of claim 10, wherein the passive evaporative cooling process includes a combination of air, water, and an absorbent pad to pre-cool the beverage containments, the absorbent pad to absorb water through capillary action, the air configured to pass across the pad to reach the beverage containments, lowering the first temperature to reach the predetermined threshold temperature, the absorbent pad configured to be applied and removed, within the cooling process, through a cartridge.

13. The system of claim 10, wherein the second step cooling mode, operating through the second working mode, is configured to be carried out through one of the following: a thermoelectric cooling;

a DC micro/mini compressor; and

an AC compressor

14. The system of claim 13, wherein a hot side of the thermoelectric cooling, when applied in the second step cooling mode, is configured to receive air, enabling a lowering of a temperature of the hot side, the air being received through the active evaporative cooling process.

15. A method of cooling in a cooling unit, the cooling unit comprising a first structure, a second structure, both the first structure and the second structure configured to accommodate one or more containments, and a temperature sensor configured to sense a temperature of the containments, the method comprising:

cooling the containments as part of a first step cooling mode in the first structure, operating through a first working mode, the cooling configured to reduce the temperature of the containments from a first temperature to a predetermined threshold temperature;

sensing the predetermined threshold temperature of the containments through the temperature sensor;

transferring the containments from the first structure to the second structure when the temperature is sensed to have reached the predetermined threshold temperature; and

cooling the containments as part of a second step cooling mode in the second structure, through a second working mode, to reduce the temperature of the containments from the predetermined threshold temperature to a final desired temperature.

16. The method of claim 15, wherein the cooling as part of the first step cooling mode, operating through the first working mode, is configured to be carried out through one of the following:

an active evaporative cooling process;

a passive evaporative cooling process;

a thermoelectric cooling;

a dual evaporator cooling;

a cooling through a phase change material;

a cooling through a natural free energy source; and

a cooling through a duct from an air conditioned environment.

17. The method of claim 16, wherein the active evaporative cooling process includes a combination of air, water, pump, and a evaporative pad to pre-cool the containments, the pump configured to supply water to the pad, the air configured to pass across the pad to reach the containments, lowering the first temperature to the predetermined threshold temperature, the evaporative pad configured to be applied and removed, within the cooling process, through a cartridge.

18. The method of claim 16, wherein the passive evaporative cooling process includes a combination of air, water, and an absorbent pad to pre-cool the containments, the absorbent pad to absorb water through capillary action, the air configured to pass across the pad to reach the containments, lowering the first temperature to reach the predetermined threshold temperature, the absorbent pad configured to be applied and removed, within the cooling process, through a cartridge.

19. The method of claim 16, wherein the cooling as part of the second step cooling mode, operating through the second working mode, is configured to be carried out through one o f the fo llo wing :

a thermoelectric cooling;

a DC micro/mini compressor; and

an AC compressor 20. The method of claim 19, wherein a hot side of the thermoelectric cooling, when applied in the second step cooling mode, is configured to receive air, enabling a lowering of a temperature of the hot side, the air being received through the active evaporative cooling process.