TECHNICAL FIELD
The present disclosure generally relates to a hybrid air cooler for delivering chilled air to an enclosed space. Particularly, the invention relates to the hybrid air cooler for delivering chilled air to an enclosed space, in a relatively efficient manner.
BACKGROUND
Air coolers are commonly known to supply chilled air. For such purposes, an air cooler intakes ambient air, chills the same, and supply chilled air to the enclosed space. One example of the air cooler is a desert air cooler. The desert air cooler comprises of a fan unit, and a water spraying unit. The fan unit generates a flow of air. The water spraying unit is adapted to spray water at the fan unit. With such functioning of the combination of the fan unit and the water spraying unit, a flow of water-aerosolized air is generated, which provides chilling effect to a person on which air is directed to. Such air coolers are incapable of providing sufficient chilling effect, if needed.
Another example of the air cooler relates to an industrial air cooler. The industrial air cooler employs an air supply unit, a primary heat-exchanger, and a secondary heat-exchanger. The air-supply unit, intakes hot ambient air, passes it through the primary heat-exchanger to be chilled, and supplies chilled air to the enclosed space. The primary heat-exchanger is a parallel-flow heat exchanger. The primary heat-exchanger employs a refrigerant flow coil, through which chilled refrigerant is passed. 'Refrigerant' may be any of known refrigerant material, for example, water. The primary heat-exchanger also employs an air flow coil, through which hot ambient air is passed to be chilled therein. Conventionally, the refrigerant flow coil and the air flow coil are arranged, such that ambient air flows in a parallel flow manner relative to the refrigerant flow. With such arrangement, heat is transferred from the hot ambient air to the

chilled refrigerant, by way of convective heat transfer. Thus, the primary heat-exchanger outputs chilled air and heated refrigerant. Further, the heated refrigerant is rechilled in the electrically powered secondary heat-exchanger, and then recirculated through the primary heat-exchanger, for air chilling purposes. In one embodiment, the secondary heat-exchanger may be a refrigeration unit that rechills the refrigerant, to be recirculated to the primary heat exchanger.
Several limitations exist in such industrial air coolers. One such limitation relates to the conventional primary heat-exchanger being a parallel flow heat-exchanger, which is relatively less efficient for heat transfer. Particularly, the output temperature of the chilled air is limited to the output temperature of the heated water. Therefore, the chilling capacity of such air cooler is relatively lesser. Additionally, convective heat transfer from the ambient air to the refrigerant, in addition to chilling of ambient air, also facilitates conditioning of air by removal of humidity from the ambient air. Therefore, only convective heat transfer requires relatively lesser inlet temperature of the chilled refrigerant, for defined output temperature of chilled air. Accordingly, in high humid areas, such air cooler are relatively inefficient to operate.
Therefore, there is an unmet need in the art to devise an air cooler that is relatively more efficient, and is suitable to be operative in high humid areas as well.
SUMMARY
One embodiment of the present disclosure relates to a hybrid air cooler for delivering chilled air to an enclosed space. The hybrid air cooler comprises of a housing defining a primary chamber and a secondary chamber. The primary cooling unit is positioned within the primary chamber, and comprises of a first and second heat exchangers. The first and second heat exchangers sequentially enable heat transfer from hot ambient air to chilled water in a counter-flow

manner, for outputting chilled air and heated water thereof. The secondary cooling unit is positioned within the secondary chamber, and comprises of a secondary heat exchanger. The secondary heat exchanger is fluidly disposed downstream of the first heat exchanger, such that the secondary heat exchanger enables heat transfer from the heated water received from the first heat exchanger to hot ambient air, for outputting partially cooled water. The refrigeration unit is disposed downstream to the secondary heat exchanger, such that the refrigeration unit refrigerates partially cooled water received from the secondary heat exchanger, for outputting chilled water to be recirculated to the primary cooling unit. The first heat exchanger is a convective cooling pad capable of enabling convective heat transfer. The second heat exchanger is an evaporative cooling pad for sequentially enabling evaporative heat transfer and refrigerated heat transfer. The secondary heat exchanger is an evaporative cooling pad for sequentially enabling evaporative heat transfer and refrigerated heat transfer.
BRIEF DESCRIPTION OF DRAWINGS
The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings. These and other details of the present invention will be described in connection with the accompanying drawings, which are furnished only by way of illustration and not in limitation of the invention, and in which drawings:
Figure 1 illustrates a flow diagram of a hybrid cooler, in accordance with the concepts of the present disclosure; and
Figure 2 illustrates a schematic of the hybrid cooler, in accordance with the concepts of the present disclosure.

Figure 3 shows a schematic of a first heat exchanger of the hybrid cooler, in accordance with the concepts of the present disclosure.
DETAILED DESCRIPTION
In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, that embodiments of the present invention may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only one of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. Example embodiments of the present invention are described below, as illustrated in various drawings in which like reference numerals refer to the same parts throughout the different drawings.
Figure 1 shows a flow diagram of a hybrid cooler [100], in accordance with the concepts of the present disclosure. Figure 2 shows a schematic of the hybrid cooler [100], in accordance with the concepts of the present disclosure. Figure 1 and Figure 2 should be referred to, in conjunction with each other, in order to clearly understand the concepts of the present disclosure. The hybrid cooler [100] includes a housing [102], a primary cooling unit [104], and a secondary cooling unit [106].
The housing [102] is a single-unit component that supports and houses the primary cooling unit [104] and the secondary cooling unit [106], in its entirety. Accordingly, the hybrid cooler [100], as disclosed in the present disclosure, can be used as a direct-use type of air cooler, and does not need separate skilled labour for installation purposes. The housing [102] is a container-type structure

that essentially defines two chambers, i.e. a primary chamber [102a] and a secondary chamber [102b]. Although, the present disclosure discloses the housing [102] including each of the primary chamber [102a] and the secondary chamber [102b], however, it may be obvious to a person ordinarily skilled in the art that the housing may include a singular chamber divided between the primary chamber portion and the secondary chamber portion. In one embodiment, the housing [102] is a cuboidal container-type structure, wherein the primary chamber [102a] is an upper structure while the secondary chamber [102b] is a lower structure. The primary chamber [102a] houses and supports the primary cooling unit [104], while the secondary chamber [102b] houses and supports the secondary cooling unit [106]. The primary cooling unit [104] and the secondary cooling unit [106], are installed in the housing [102], which in conjunction, facilitates a supply of chilled air to an enclosed space. In an embodiment, the enclosed space may be a single room, or multiple rooms. Further, the primary chamber [102a] defines a primary air inlet [102c] and a primary air outlet [102d] defined proximal to bottom and top of the primary chamber [102a], respectively. In particular, the primary air inlet [102c] is defined proximal to bottom of the primary chamber [102a], while the primary air outlet [102d] is defined proximal to top of the primary chamber [102a]. Additionally, the primary chamber [102a] defines a primary water inlet [102e] and a primary water outlet [102f] defined proximal to top and bottom of the primary chamber [102a], respectively. In particular, the primary water inlet [102e] is defined proximal to top of the primary chamber [102a], while the primary water outlet [102f] is defined proximal to bottom of the primary chamber [102a]. Furthermore, the secondary chamber [102b] defines a secondary air inlet [102g] and a secondary air outlet [102h], on separate faces of the secondary chamber [102b]. Concepts of the present disclosure with regards to the primary chamber [102a] and the secondary chamber [102b], for facilitating the supply of chilled air to the enclosed space, will be discussed hereinafter.

The primary cooling unit [104] is positioned within the primary chamber [102a]. The primary cooling unit [104] includes a first heat exchanger [108], a second heat exchanger [110], and a blower unit [112]. Each of the first heat exchanger [108] and the second heat exchanger [110] are installed and disposed within the primary chamber [102a], wherein the first heat exchanger [108] is disposed lower in height than the second heat exchanger [110]. Notably, the first and second heat exchangers [108, 110] sequentially enables heat transfer from hot ambient air to chilled water in a counter-flow manner, for outputting chilled air and heated water thereof. The blower unit [112] is installed and disposed within the primary chamber [102a] above the second heat exchanger [110], such that the blower unit [112] generates the airflow of hot ambient air sequentially through each of the first heat exchanger [108] and the second heat exchanger [110], in an airflow direction. In particular, the blower unit [112] enables receipt of hot ambient air, passes it through the first heat exchanger [108] and the second heat exchanger [110] to be chilled, and outputs chilled air. The second heat exchanger [110] is fluidly disposed upstream of the first heat exchanger [108] in a waterflow direction, and is fluidly disposed downstream of the of the first heat exchanger [108] in an airflow direction. Notably, the airflow direction is opposite to the waterflow direction. Therefore, chilled water enters the second heat exchanger [110] through the primary water inlet [102e], while hot ambient air enters the first heat exchanger [108] through the primary air inlet [102c]. 'Chilled water' and 'hot ambient air' sequentially flows through the first heat exchanger [108] and the second heat exchanger [110], in the waterflow direction and the airflow direction, respectively, to output the 'heated water' and the 'chilled air'. Therefore, 'heated water' is outputted from the first heat exchanger [108] through the primary water outlet [102f], while 'chilled air' is outputted from the second heat exchanger [110] to the primary air outlet [102d]. In an embodiment, an air duct fluidly connects the primary air outlet [102d] to the

enclosed space, for directing the chilled air from the primary air outlet [102d] to the enclosed space.
The first heat exchanger [108] is a convective cooling pad capable of enabling convective heat transfer from the hot ambient air to the chilled water. The first heat exchanger [108] is made up of aluminum material suitably shaped to form a plurality of longitudinally extending honey-comb structured cavities [108a, 108b], wherein the honey-comb structured cavities include a first array of cavities for upward airflow [108a] and a second array of cavities for downward waterflow [108b]. Each of the first array of cavities for upward airflow [108a] are fluidly connected with each other at ends, while the second array of cavities for downward waterflow [108b] are fluidly connected with each other at ends. With such arrangement, the first array of cavities for upward airflow [108a] can be used to allow flow of hot ambient air therethrough, while the second array of cavities for downward waterflow [108b] can be used to allow flow of chilled water therethrough. Further, the first array of cavities for upward airflow [108a] and the second array of cavities for downward waterflow [108b] are arranged together, such that it allows heat transfer from the hot ambient air to the chilled water, in a convective manner.
The second heat exchanger [110] is an evaporative cooling pad for sequentially enabling evaporative heat transfer and refrigerated heat transfer. The second heat exchanger [110] employs an airflow tube and a waterflow tube, each of which is suitably bent to be installed within the second heat exchanger [110]. Further, the airflow tube and the waterflow tube are suitably arranged relative to each other, such that the second heat exchanger [110] sequentially enables evaporative heat transfer and refrigerated heat transfer, between 'chilled water' and 'hot ambient air'. In particular, a first half of the second heat exchanger [110] enables evaporative heat transfer between 'chilled water' and 'hot

ambient air', while a second half of the second heat exchanger [110] enables refrigerated heat transfer between 'chilled water' and 'hot ambient air'.
The secondary cooling unit [106] is positioned within the secondary chamber [102b]. The secondary cooling unit [106] is adapted to receive heated water from the first heat exchanger [108] of the primary cooling unit [104], rechill the same, and then store the chilled water in water tank [114], to be recirculated to the second heat exchanger [110] of the primary cooling unit [104], when required. The secondary cooling unit [106] includes a secondary heat exchanger [116] and a refrigeration unit [118]. Each of the water tank [114], the secondary heat exchanger [116], and the refrigeration unit ]118], are installed and disposed within the secondary chamber [102b] of the housing [102], wherein the water tank [114] is disposed beneath the secondary heat exchanger [116] and the refrigeration unit ]118]. The secondary heat exchanger [116] and the refrigeration unit ]118], in conjunction with each other, receives heated water from the first heat exchanger [108] of the primary cooling unit [104], rechills the same, and stores in the water tank [114]. A fluid pump [120] is then used to recirculate the chilled water from the water tank [114] to the second heat exchanger [110] of the primary cooling unit [104].
The secondary heat exchanger [114] of the secondary cooling unit [106] is fluidly disposed downstream to the first heat exchanger [108] of the primary cooling unit [104] in the waterflow direction. The secondary heat exchanger [114] of the secondary cooling unit [106] is adapted to receive the heated water, as received from the first heat exchanger [110] of the primary cooling unit [104], cools the same, and output partially chilled water. Additionally, the hot ambient air is received therein through the secondary air inlet [102g], passed through the secondary heat exchanger [114] to be cooled, and chilled air is then vent through the secondary air outlet [102h]. In particular, the secondary heat exchanger [114] is adapted to perform heat exchange between the heated water and the

hot ambient air, sequentially in each of the evaporative heat transfer manner and refrigerated heat transfer manner. In particular, the secondary heat exchanger [114] is an evaporative cooling pad for sequentially enabling evaporative heat transfer and refrigerated heat transfer. The secondary heat exchanger [114] employs an airflow tube and a waterflow tube, each of which is suitably bent to be installed within the secondary heat exchanger [114]. Further, the airflow tube and the waterflow tube are suitably arranged relative to each other, such that the secondary heat exchanger [114] sequentially enables evaporative heat transfer and refrigerated heat transfer, between 'heated water' and 'hot ambient air'. In particular, a first half of the secondary heat exchanger [114] enables evaporative heat transfer from the 'heated water' to the 'hot ambient air', while a second half of the secondary heat exchanger [114] enables refrigerated heat transfer from the 'heated water' to 'hot ambient air', to output partially chilled water.
Further, at least one component of the refrigeration unit [118] of the secondary cooling unit [106] is fluidly installed downstream of the secondary heat exchanger [114] of the secondary cooling unit [106], in the waterflow direction. The refrigeration unit [118] is a conventionally known refrigeration unit, comprising of a compressor, a condenser, an expander, and an evaporator. In particular, the evaporator of the refrigeration unit [118] is fluidly installed downstream of the secondary heat exchanger [114] of the secondary cooling unit [106], in the waterflow direction. Accordingly, the evaporator of the refrigeration unit [118] receives partially chilled water from the secondary heat exchanger [114], chills the same, and outputs chilled water to the water tank [114].
It may be obvious to a person ordinarily skilled in the art that the fluid pump [120], the blower unit [112], and the refrigeration unit [118], are electrically actuated components, upon actuation of a supply of power to the hybrid air cooler [100]. In operation, as a user activates the supply of power to the hybrid

air cooler [100], each of the fluid pump [120], the blower unit [112], and the refrigeration unit [118], are activated. Activation of the fluid pump [120] corresponds to circulation of chilled water stored in the water tank [114] to the primary water inlet [102e], to be further supplied to the second heat exchanger [110] and the first heat exchanger [108] of the primary cooling unit [104]. Moreover, activation of the blower unit [112] corresponds to sucking of hot ambient air through the primary air inlet [102c], to be further supplied to the second heat exchanger [110] and the first heat exchanger [108] of the primary cooling unit [104]. Notably, the chilled water is dripped downwards due to gravitational force in the waterflow direction, while the hot ambient air is sucked by the blower unit [112] in the airflow direction. As the waterflow direction is opposite to the airflow direction, the hot ambient air and the chilled water are passed through each of the first heat exchanger [108] and the second heat exchanger [110] in the counterflow manner. Therefore, the first and the second heat exchangers [108, 110] sequentially enables heat transfer from hot ambient air to chilled water in a counter-flow manner, for outputting chilled air and heated water thereof. In particular, firstly, in the first heat exchanger [108], convective heat transfer is enabled to transfer heat from the hot ambient air to the chilled water. Later, in the second heat exchanger [110], the evaporative cooling and the refrigerated cooling are sequentially enabled to further transfer heat from the hot ambient air to the chilled water. Therefore, the ambient air is chilled to be outputted as chilled air, while chilled water is heated to be outputted as heated water. Accordingly, it may be said that in the present disclosure, the hot ambient air is chilled to be outputted as chilled air, following the three stages of cooling, namely convective heat transfer, evaporative heat transfer, and refrigerated heat transfer. The chilled air, received at the primary air outlet [102d], is transferred to the enclosed space for chilling the same.
Furthermore, the heated water is received in the secondary cooling unit [106], rechilled by the secondary heat exchanger [116] and the refrigeration unit [118]

therein, and then recirculated to the primary cooling unit [104]. In particular, the heated water from the first heat exchanger [108] is received at the secondary heat exchanger [116], and the hot ambient air is also received within the secondary heat exchanger [116] through the secondary air inlet [102g]. The secondary heat exchanger [116] thus performs two-stage cooling of the heated water therein, namely evaporative heat transfer, and refrigerated heat transfer, to output the chilled water to the water tank [114]. Further, the fluid pump [120] recirculates the chilled water to the primary cooling unit [104] to perform primary cooling of ambient air.
One advantage of the present disclosure relates to the first and second heat exchangers [108, 110] sequentially enabling heat transfer from hot ambient air to chilled water in the counter-flow manner. Such heat transfer in the counter-flow manner is relatively more efficient. In particular, with such heat transfer in the counter-flow manner, the output temperature of the chilled air, is not dependent on output temperature of the heated water, but can reach as low as the input temperature of the chilled water. Accordingly, the hybrid air cooler [100] as disclosed in the present disclosure, has relatively more chilling capacity.
Another advantage of the hybrid cooler [100], as disclosed in the present disclosure, relates to three-stage cooling of the hot ambient air. In particular, the primary cooling unit [104] and the secondary cooling unit [106], in conjunction with each other, enables three stages of cooling, namely convective heat transfer (at the first heat exchanger [108] of the primary cooling unit [104]), the evaporative heat transfer (at the second heat exchanger [110] of the primary cooling unit [104]), and the refrigerated heat transfer (at the second heat exchanger [110] of the primary cooling unit [104]). Therefore, it avoids requirement of conditioning of air, and thus the hybrid cooler [100], as disclosed in the present disclosure, can work at relatively increased inlet temperature of the chilled water. Therefore, the secondary cooling unit [108] will need relatively

less energy. In brevity, the hybrid cooler [100], as disclosed in the present disclosure, has more chilling capacity without any increase in power consumption.
Furthermore, another advantage of the hybrid cooler [100], as disclosed in the present disclosure, relates to the secondary heat exchanger [116] of the secondary cooling unit [106], for cooling the heated water in two stage cooling, namely evaporative cooling and the refrigerated cooling. Similar to the three-stage cooling of the primary cooling unit [104], this two stage cooling further enhances chilling capacity without any increase in power consumption.
Finally, yet another advantage of the hybrid cooler [100], as disclosed in the present disclosure, relates to the housing [102] being a single-unit structure. As the housing [102] is a single-unit structure that houses and support the entire primary cooling unit [104] and the secondary cooling unit [106]. Therefore, the hybrid cooler [100], as disclosed in the present disclosure, can be provided and installed as a single ready-to-use structure. This avoids need of any skilled labour, for installation.
Although particular embodiments have been disclosed herein in detail, this is for illustrative purposes only and is not intended in any way to limit the intended scope of the invention, variations and adaptions of the system and method as described herein that do not depart from the spirit and scope of the invention and within the expertise of a person skilled in the art.
List of Components:
100-Hybrid Air Cooler
102-Housing
102a - Primary Chamber

102b - Secondary Chamber
102c- Primary Air Inlet
102d - Primary Air Outlet
102e - Primary Water Inlet
102f - Primary Water Outlet
102g - Secondary Water Inlet
102h - Secondary Water Outlet
104 - Primary Cooling Unit
106 - Secondary Cooling Unit
108 - First Heat Exchanger
108a - First array of cavities for upward airflow
108b - Second array of cavities for downward waterflow
110 - Second Heat Exchanger
112-Blower Unit
114-Water Tank
116 - Secondary Heat Exchanger
118 - Refrigerating Unit
120-Fluid Pump

I/We Claim:

1. A hybrid air cooler [100] for delivering chilled air to an enclosed space, the hybrid air cooler [100] comprising:
a housing [102] defining a primary chamber [102a] and a secondary chamber [102b];
a primary cooling unit [104] positioned within the primary chamber [102a], the primary cooling unit [104] comprising:
a first and second heat exchangers [108, 110] sequentially enabling heat transfer from hot ambient air to chilled water in a counter-flow manner, for outputting chilled air and heated water thereof; and
a secondary cooling unit [106] positioned within the secondary chamber [102b], the secondary cooling unit [106] comprising:
a secondary heat exchanger [116] fluidly disposed downstream of the first heat exchanger [108] in a waterflow direction, such that the secondary heat exchanger [116] enables heat transfer from the heated water received from the first heat exchanger [108] to hot ambient air, for outputting partially cooled water; and
a refrigeration unit [118] disposed downstream to the secondary heat exchanger [116] in the waterflow direction, such that the refrigeration unit [118] refrigerates partially cooled water received from the secondary heat exchanger [116[, for outputting chilled water to be recirculated to the primary cooling unit [104], wherein
the first heat exchanger [108] is a convective cooling pad capable of enabling convective heat transfer, the second heat exchanger [110] is an evaporative cooling pad for sequentially enabling evaporative heat

transfer and refrigerated heat transfer, the secondary heat exchanger [116] is an evaporative cooling pad for sequentially enabling evaporative heat transfer and refrigerated heat transfer.
2. The hybrid air cooler [100] as claimed in claim 1, wherein the primary cooling unit [104] comprises of a primary air inlet [102c] and a primary air outlet [102d] defined proximal to bottom and top of the primary chamber [102a], respectively, for receiving the hot ambient air from external environment and delivering the chilled air to the enclosed space.
3. The hybrid air cooler [100] as claimed in claim 1, wherein the primary cooling unit [104] comprises of a primary water inlet [102e] and a primary water outlet [102f] defined proximal to top and bottom of the primary chamber [102a], respectively, for receiving chilled water from the secondary cooling unit [106], and exiting heated water to the secondary cooling unit [106], thereof.
4. The hybrid air cooler [100] as claimed in claims 1-3, wherein the first and second heat exchangers [108, 110] are fluidly disposed between each of the pair of primary air inlet [102c] and primary air outlet [102d] and the pair of primary water inlet [102e] and the primary water outlet [102f], such that each of the first and second heat exchangers [108, 110] sequentially enables heat transfer from the hot ambient air to the chilled water in the counter-flow manner.
5. The hybrid air cooler [100] as claimed in claims 1-3, wherein the primary cooling unit [104] comprises of a blower unit [112] for enabling receipt of the hot ambient air from external environment through the primary air inlet [102c] and delivering the chilled air to the enclosed space through the primary air outlet [102d].

6. The hybrid air cooler [100] as claimed in claim 1, wherein the first heat exchanger [108] has a honey-comb structure including a first array of cavities for upward airflow [108a] and a second array of cavities for downward waterflow [108b], such that the first heat exchanger [108] is capable of enabling convective heat transfer.
7. The hybrid air cooler [100] as claimed in claim 1, wherein the primary cooling unit [104] comprises of an air duct fluidly connecting the primary air outlet [102d] to the enclosed space, for directing the chilled air from the primary air outlet [102d] to the enclosed space.
8. The hybrid air cooler [100] as claimed in claim 1, wherein the secondary cooling unit [106] comprises of a secondary air inlet [102g] and a secondary air outlet [102h].
9. The hybrid air cooler [100] as claimed in claim 1, wherein each of the secondary heat exchanger [116] and the refrigeration unit [118] are fluidly disposed between the secondary air inlet [102g] and a secondary air outlet [102h], for receiving the hot ambient air from external environment and releasing further heated ambient air to the external environment.
10. The hybrid air cooler [100] as claimed in claim 1, wherein the secondary cooling unit [106] includes a water tank [114] for storing chilled water outputted from the secondary heat exchanger [116] of the secondary cooling unit [106] thereof.
11. The hybrid air cooler [100] as claimed in claim 1-10, further includes a fluid pump [120] for recirculating the chilled water from the water tank [114] of the secondary cooling unit [106] to the primary cooling unit.
12. The hybrid air cooler [100] as claimed in claim 1, wherein the housing

[102] is a single-unit component that defines the primary chamber [102a] for carrying the primary cooling unit [104], and the secondary chamber [102b] for carrying the secondary cooling unit [106].