WO2023238062A1

WO2023238062A1 - Methods and systems for passive cooling and sanitization of defined space

Info

Publication number: WO2023238062A1
Application number: PCT/IB2023/055884
Authority: WO
Inventors: Zubin Varghese; Balegundi L. Rohith; Jeyaprakash GURUSAMY; Praveena Alangar Subrahmanya; Sandeep Vageeshwara; Shriraj Nair; Thirumalai PRABHAKARAN; Jin Sheng ZHOU
Original assignee: Trane International Inc.
Priority date: 2022-06-07
Filing date: 2023-06-07
Publication date: 2023-12-14
Also published as: AR129561A1; TW202412681A

Abstract

Methods and systems for passive cooling and sanitization are provided. The system includes a roof positioned to provide a shielding to the conditioned space underneath the roof, and a radiative film disposed on an upper surface of the roof and configured to provide radiative cooling to the conditioned space. In some cases, one or more platforms are positioned below the roof to define the conditioned space. A positioning mechanism is used to move at least one of the roof and the one or more platforms upward and downward between an open position and a closed position to adjust a height of the conditioned space.

Description

METHODS AND SYSTEMS FOR PASSIVE COOLING AND SANITIZATION OF DEFINED SPACE

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Indian Provisional Patent Application Serial Nos. 202241032466, filed on June 7, 2022 and 202241043837, filed on August 1, 2022. The disclosures of the prior applications are considered part of the disclosure of this application, and are incorporated in their entirety into this application.

TECHNICAL FIELD

This disclosure relates generally to systems, methods, and designs of passive cooling and/or sanitization of a conditioned space. More specifically, the disclosure relates to a collapsible apparatus to provide a conditioned space with passive cooling and/or sanitization.

BACKGROUND

Across the world, one third of the food is wasted. This waste also leads to massive greenhouse gas emissions. The biggest component of food waste is fruits and vegetables. Much of the fruits and vegetables in developing countries are sold through street vendors. Research shows that the cumulative loss incurred by the millions of street vendors worldwide amounts to billions of dollars annually, which is a significant percentage of global food loss and waste.

SUMMARY

There is a desire to provide cost-effective ways for passive cooling and sanitization of a defined space, in particular, to provide street vendors an affordable, comprehensive vending platform.

Briefly, in one aspect, the present disclosure describes an apparatus to provide a conditioned space. The apparatus includes a roof positioned to provide a shielding to the conditioned space underneath the roof, and a radiative film disposed on an upper surface of the roof and configured to provide radiative cooling to the conditioned space. In some cases, the apparatus further includes one or more platforms positioned below the roof to define the conditioned space. In some cases, the apparatus further includes a positioning mechanism configured to move at least one of the roof and the one or more platforms upward and downward between an open position and a closed position to adjust a height of the conditioned space.

Various advantages are obtained in exemplary embodiments of the disclosure. One such advantage is that the modular design of an apparatus having a roof or canopy with an adjustable height provides retrofittable and cost-effective solutions for cooling and/or sanitization in a conditioned space.

Various aspects and advantages of exemplary embodiments of the disclosure have been summarized. The above Summary is not intended to describe each illustrated embodiment. Other features and aspects will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings that form a part of this disclosure and which illustrate the embodiments in which systems and methods described in this specification can be practiced.

FIG. 1 A is a schematic diagram of an apparatus, according to one embodiment.

FIG. IB is a side perspective view of an apparatus to provide a conditioned space, according to one embodiment.

FIG. 2A is a side perspective view of a cart, according to one embodiment.

FIG. 2B is a side perspective view of a cart, according to another embodiment.

FIG. 2C is a side perspective view of a roof, according to one embodiment.

FIG. 2D is another side perspective view of the roof of FIG. 2C.

FIG. 3 is a side perspective view of a cart, according to one embodiment.

FIG. 4A is a schematic diagram of a scissor mechanism, according to one embodiment.

FIG. 4B is a schematic diagram of the scissor mechanism of FIG. 4A in a closed position.

FIG. 4C is a schematic diagram of the scissor mechanism of FIG. 4A in an opened position.

FIG. 5A is a side perspective view of a cart including a chain and sprocket mechanism, according to one embodiment.

FIG. 5B is a side perspective view of the chain and sprocket mechanism of FIG. 5B in a closed position. FIG. 5C is a side perspective view of the chain and sprocket mechanism of FIG. 5B in a closed position.

FIG. 6A is a side perspective view of a cart including a bellow, according to one embodiment.

FIG. 6B is a side perspective view of the bellow of FIG. 6A in an expanded condition.

FIG. 6C is a side perspective view of the bellow of FIG. 6A in a closed condition.

FIG. 7A is a side perspective view of a cart including a collapsible pillar, according to another embodiment.

FIG. 7B is a cross-sectional view of the cart of FIG. 7A in an opened condition.

FIG. 7C is a cross-sectional view of the cart of FIG. 7A in a closed condition.

FIG. 7D is a side perspective view of a cart, according to one embodiment.

FIG. 7E is an enlarged portion view of the cart of FIG. 7D in an opened condition.

FIG. 7F is an enlarged portion view of the cart of FIG. 7D in a closed condition.

FIG. 7G is a side perspective view of a cart, according to one embodiment.

FIG. 7H is an enlarged portion view of the cart of FIG. 7G.

FIG. 8A is a cross-sectional view of an apparatus including a charged water distribution mechanism, according to one embodiment.

FIG. 8B is a cross-sectional view of an apparatus including a charged water distribution mechanism, according to another embodiment.

FIG. 8C is a schematic diagram of a water treatment system.

FIG. 9A is a cross-sectional view of an apparatus including a thermal storage tank in a first position, according to one embodiment.

FIG. 9B is a cross-sectional view of the thermal storage tank of FIG. 9A in a second position.

FIG. 10A is a cross-sectional view of an apparatus including a dual-tank cooling system in a first condition, according to one embodiment.

FIG. 1 OB is a cross-sectional view of the apparatus including the dual-tank cooling system of FIG. 10A in a second condition.

FIG. 11 A is a cross-sectional view of an apparatus including a thermosyphon cooling mechanism, according to one embodiment. FIG. 1 IB is a schematic diagram of a thermosyphon cooling mechanism, according to one embodiment.

FIG. 12 is a side view of an apparatus including a cooling system including a thermal energy storage tank and an air duct, according to one embodiment.

Particular embodiments of the present disclosure are described herein with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. In this description, as well as in the drawings, like-referenced numbers represent like elements that may perform the same, similar, or equivalent functions.

DETAILED DESCRIPTION

This disclosure relates generally to systems, methods, and designs of passive cooling and/or sanitization of a conditioned space. More specifically, the disclosure relates to a collapsible apparatus to provide a conditioned space with passive cooling and/or sanitization. In some cases, the collapsible apparatus may have a modular cart structure with or without wheels. The cart includes a platform to keep items (e.g., perishables) and a collapsible roof with a radiative film to provide passive radiative cooling to the space underneath the roof. In some cases, the collapsible apparatus further includes a charged water mechanism and a cooling mechanism to provide sanitization and further cooling to the items on the platform. The systems and methods described herein provide passive cooling and sanitization in a conditioned space. In other words, the systems and methods can be implemented without a substantial external power source. For example, the cooling and sanitization function may be operated by a user’s manual actions, and optionally, supplemented by a small power source such as a battery (e.g., a solar cell battery, a 9V battery, a battery pack, a battery charged from an axel generator, etc.). In some cases, the systems described herein may include a mobile device such as a navigation device (e.g., GPS) to provide geolocation and time information. Some embodiments of the present application are described in detail with reference to the accompanying drawings so that the advantages and features of the present application can be more readily understood by those skilled in the art. The terms “near”, “far”, “top”, “bottom”, “left”, “right”, and the like described in the present application are defined according to the typical observation angle of a person skilled in the art and for the convenience of the description. These terms are not limited to specific directions.

FIG. 1A is a schematic diagram of an apparatus 100, according to one embodiment. The apparatus 100 is configured to provide a conditioned space 3. The apparatus 100 includes a platform 10, a roof 20 positioned above the platform 10 to define the conditioned space 3 therebetween, and a positioning mechanism 30 configured to move at least one of the roof 20 and the platform 10 upward and downward (as indicted by the arrow 31) with respective to each other between an open position and a closed position to adjust the height of the conditioned space 3. The roof 20 has an upper surface 22 where a radiative film 24 is disposed on the side opposite the platform 10. The radiative film 24 is configured to provide radiative cooling to the conditioned space 3.

The radiative film 24 can be disposed onto a base material or a substrate with a structural support to enhance its overall structural integrity of the roof 20. The radiative film 24 can have a thickness, for example, between 10 microns and 200 microns, or between 30 microns and 100 microns. One exemplary radiative film may have a multi-layered structure with a thickness around 80 microns. The base material can include a thermally conductive material such as, for example, a metal (e.g., aluminum) plate. The structural support may be a combination of wood, steel, fabric, and any other suitable materials. The radiative film 24 can reflect a substantial amount of incident solar light (as indicated by the arrows “i” and “r”) and dissipate heat in the form of radiant energy (as indicated the arrows “n”) into the sky. It is to be appreciated that similar arrows “i”, “r” and “n” are used in other figures to indicate the same. A suitable radiative film used herein may have a high reflectivity in solar wavelengths, and a high emissivity in longer infrared wavelengths. The cooling effect from a radiative film occurs through a natural phenomenon called radiative cooling. Radiative cooling refers to a process where a body can emit as radiation heat energy absorbed through normal convection and conduction processes. A radiative film can cool a base material or a substrate below the ambient temperature with no electricity input, and without evaporating water. In some cases, a radiative film can even cool to sub-ambient temperatures while under direct sunlight. In some cases, a passive radiative cooling film may provide net cooling powers up to, for example, 20 W/m² to 100 W/m² and 50 W/m² to 200 W/m² during daytime and nighttime, respectively, which may cool an underneath substrate by, for example, 2 ° C to 8° C below ambient temperature.

In some cases, the radiative film 24 can be formed by applying surface coatings having radiative cooling properties onto the upper surface 22 of the roof 20. Exemplary coating compositions to form a radiative cooling surface coating were described in U.S. Patent No. 7,503,971, which is incorporated herein by reference. One exemplary composition may include a solar reflective pigment and a quantity of microspheres to provide a high reflectance of solar radiation. The microspheres can enhance the emittance of the coating such that the coating has a high radiative emittance in a wavelength range of 8 micrometers to 13 micrometers to emit thermal energy in the wavelength range.

In some cases, the radiative film 24 may include a solar reflective film having a multilayer optical structure with passive radiative cooling capabilities. It is to be understood that a radiative film used herein may have various configurations and compositions as long as it can exhibit passive radiative cooling capabilities with a reflectivity in solar wavelengths, and an emissivity in longer infrared wavelengths (e.g., 8 micrometers to 13 micrometers) that is sufficiently high to provide cooling effect.

When the apparatus 100 is used as a vending machine such as, for example, a street vendor cart, the perishables 4 can be disposed on the platform 10 within the conditioned space 3 to increase the shelf life of the perishables, reduce weight loss, enable evaporative cooling, maintain freshness, etc. It is to be understood that the apparatus 100 can be used for any desired applications to provide a conditioned space with passive cooling and sanitization along with thermal storage, and the perishables 4 can be any other items to be positioned within or adjacent to the conditioned space 3.

An apparatus or system described herein may have a retrofit design for various applications. The retrofit design allows various components of the apparatus/system to be added or removed, to be used together as an assembly, or to be used separately to provide the desired functions of cooling and/or sanitization to a conditioned space underneath a roof. In some cases, an apparatus may include a roof and one or more platforms that can be assembled as a cart such as a street-vendor cart. In some cases, a roof with a radiative film and a suitable mounting mechanism may be provided to an existing cart having a platform. For example, the roof 20 of FIG. 1 A may be used separately without being assembled with the platform 10 and the positioning mechanism 30. In some cases, an apparatus or system described herein may include multiple platforms arranged in various suitable configuration for, e.g., a poultry delivery, a vegetable harvest, etc. For example, the platform 10 of FIG. 1A may have multiple layers or subplatforms to keep items 4 in a layered structure. In some cases, an apparatus may be used for a shelter structure (e.g., a bus shelter, a home shelter), where a roof with a radiative film can be provided without using a positioning mechanism and/or a platform.

FIG. IB illustrates an apparatus 130 carried by a wheelbarrow 11 to provide a conditioned space, according to one embodiment. The apparatus 130 can include the same or similar features as apparatus 100 of FIG. 1A. The apparatus 130 may include any canopy or roof structures described herein. In the embodiment depicted in FIG. IB, the canopy or roof 130 is connected to a platform 10 carried by the wheelbarrow 11. It is to be understood that the apparatus 130 may have a retrofit design for various applications. In some cases, the apparatus 130 may include one or more roofs and one or more platforms that can be carried or supported by any suitable carrying tools such as, for example, a wheelbarrow, a cart, etc. In some cases, the one or more platforms may be integrated with the carrying tools, to which the one or more roofs can be assembled.

In the embodiment depicted in FIG. IB, the canopy or roof 130 includes a frame 135 to support one or more sides 134 and door 136. The sides 134 and/or the door 136 may be made of a transparent or semi-transparent material (e.g., a polycarbonate sheet). In some embodiments, the sides 134 and/or the door 136 may have a mesh structure. The radiative film 24 is disposed on the upper surface 132 of the canopy 130 on the side opposite the platform 10. The upper surface 132 may have a sloped angle with respect to the platform 10 in a range, for example, 0 to 5 degrees, or about 3 degrees. The door 136 can be open by rotating about an edge of the frame 135 via, e.g., hinges 131, in a direction as indicated by arrow 131a.

In an embodiment, the upper surface 132, as one piece, may be rotatable along with the door 136, in a direction as indicated by arrow 131b. In this manner, the upper surface 132 can be open along with the door 136. In another embodiment, a portion of the upper surface 132 may be fixed to the frame 135 and another portion may be rotatable along a folding line 133 via, e.g., hinges 131, in a direction as indicated by arrow 131c when the door 136 is open. In this manner, a portion (e.g., half) of the upper surface 132 can be open along with the door 136. By opening at least a portion of the upper surface 132 along with the door 136, a user can conveniently load goods into the conditioned space.

The platform 10 may have any platform structures described herein. In the embodiment depicted in FIG. IB, the platform 10 is connected, e.g., via, one or more mounting brackets, to an upper edge of a tray 113 of the wheelbarrow 11. The canopy 130 can be assembled with the platform 10 with the door 136 facing the sides not blocked by the handle 115 or the wheel 5 of the wheelbarrow 11. The frame 135 of the canopy 130 may be connected to the platform 10 by any suitable mounting mechanism. One or more latches 12 are provided to lock the door 136 on the platform 10. The platform 10 has an opening 73 to access to the inside of the tray 113. A cover can be provided to secure the opening 73 and store goods within the tray 113. The canopy 130 and the platform 10 may each may have a frame structure with a structural support made of wood, steel, fabric, metal plate, or a combination thereof.

FIG. 2A is a side perspective view of a cart 200, according to one embodiment. The cart 200 includes the platform 10, the roof 20 positioned above the platform 10 to define the conditioned space therebetween, and multiple collapsible pillars 32 connecting the roof 20 to the platform 10. The pillars 32 each may be collapsible to allow the roof 20 be collapsed so that it can act as a shield for items on the platform 10 for night-time storage with a locking system. In addition, the roof height with respect to the platform 10 may be adjusted as desired by adjusting the collapsible pillars 32. The cart 200 further includes a fixed or detachable type storage box 7 which can be provided with a locking option on the bottom of the platform 10. The box 7 has an opening and cover 71 on the upper surface of the platform 10 to secure and store goods within the cart after sale. In the embodiment depicted in FIGS. 2A and 2B, optional wheels 5 are provided to allow the movement of cart 200 from place to place.

As shown in FIG. 2 A, a cutout 15 is provided on the platform 10 to accommodate a person under the shelter of roof 20. In another embodiment depicted in FIG. 2B, the cart 200’ includes a collapsible overhang 26 that is attached to one side of the roof 20 to provide a shelter when it is in an extended position. The collapsible overhang 26 can have the radiative film 24 on the roof 20 to extend to cover its upper surface to provide radiative cooling. The collapsible overhang 26 can be detachable from the roof 20 and be fitted to any side of the roof 20. FIG. 2C is a side perspective view of the roof 20, according to one embodiment. FIG. 2D is another side perspective view of the roof 20 of FIG. 2C. The roof 20 includes a sloped upper surface 22 where the radiative film 24 is applied thereon. In some cases, the upper surface 22 may have a sloped angle with respect to the platform 10 in a range, for example, 5 to 15 degrees. It is to be understood that the sloped angle may be adjustable by, for example, adjusting the respective heights of the pillars 32 when the car is in an open position. In some cases, the upper surface 22 of the roof 20 may be flat. The upper surface 22 may further include one or more corrugation structures (e.g., ridges, and/or grooves). The collapsible overhang 26 is attached to a side 21 of the roof 10 and can be extended as a portion of the upper surface 22 to provide shielding. A gas spring 29 is provided on the side 21 to support the collapsible overhang 26. The sides 21, 23, 25, 27, along with the upper surface 22, define an at least partially enclosed space 51 which has an opening facing the conditioned space 3 when the roof 20 is assembled to the cart 200, 200’ as shown in FIGS. 2A-2B.

A roof described herein may have a frame structure with a structural support made by, for example, a combination of wood, steel, fabric, metal plate, and any other suitable materials in any suitable configurations. In some cases, a roof may include one or more movable or removable parts (e.g., a lid) to allow opening or partial movements of the roof. The roof may have a flat or structured upper surface with a radiative film or material disposed thereon. The roof surface may be tilted or horizontal. As shown in FIG. 2D, a sealing mechanism 28 is provided over a bottom edge of the roof 20 and is configured to secure an engagement of the roof 20 and the platform 10 at a closed position. In some cases, the sealing mechanism may include a rubber bead to secure the seating of roof 10 over the platform 10 in the closed condition and prevent temperature leakage from the enclosed space.

In various embodiments, a roof is connected to a platform via a positioning mechanism that facilitates the upward and downward motion of at least one of the roof and the platform with respect to each other, and locks the apparatus at required positions. In some cases, the positioning mechanism moves the roof upward and downward with respect to the platform which may be fixed. In some cases, the platform may be movable upward and downward using the same or different positioning mechanism. At least one pillar, preferably, multiple pillars (e.g., 3 or 4 pillars) is provided that can smoothly guide the movement of the roof and the platform with respect to each other. In the embodiment depicted in FIG. 3, the positioning mechanism 30 includes a scissor mechanism 40 positioned between two pillars 32 on one side of the cart 300 to facilitate the opening and closing of the cart 300. As further shown in FIG. 4A, the scissor mechanism 40 includes first and second supports 42, 44 pivotally connected at a riveted joint 41 in a crisscross “X” pattern. The scissor mechanism 40 further includes a moving mechanism located at the platform 10 to move a first end 42a of the first support 42, and a mounting block 422 mounted on the roof 20 to pivotally connect to a second end 42b of the first support 42. The moving mechanism includes a handle 48 and a lead screw 46 that rotates by manually turning the handle 48. The scissor mechanism 40 further includes a slider 49 mounted on the roof 20 to guide a first end 44a of the second support 44, and a mounting block 442 mounted on the platform 10 to pivotally connected to a second end 44b of the second support 44. It is to be understood that the moving mechanism may include any suitable means or components to operate the scissor mechanism 40 in any position between a closed position as shown in FIG. 4B and an opened position as shown in FIG. 4C. The scissor mechanism 40 can be manually driven (e.g., by using the handle 48) or be driven by a motor powered by a small power source such as, for example, a solar cell battery.

In the embodiment depicted in FIG. 5 A, the positioning mechanism 30 includes a chain and sprocket mechanism 50 positioned between two pillars 32 on one side of the cart 300’ to facilitate the opening and closing of the cart 300’. The chain and sprocket mechanism 50 has a first end 50a connected to the platform 10 and a second end 50b connected to the roof 20. A driven mechanism 52 is provided to move the second end 50b away or towards the first end 50a in any position between a closed position as shown in FIG. 5 B and an opened position as shown in FIG. 5C. It is to be understood that any suitable cascade mechanism other than a chain and sprocket mechanism can be used to facilitate the upward and downward motion of the roof 20 and locks it at the required positions.

In some cases, a positioning mechanism further includes a collapsible cover to enclose the components thereof to prevent undesired interaction with the components and subsequent injuries. The cover also protects the positioning mechanism from foreign objects that can hinder its functioning and avoids direct exposure of mechanism parts to the environment. In the embodiment depicted in FIG. 6 A, a bellow 37 is provided to enclose the positioning mechanism 40, 50 along with the adjacent pillars 32. The bellow 37 is collapsible and extendable between an opened condition as shown in FIG. 6B and a closed condition as shown in FIG. 6C.

In some cases, one or more collapsible pillars can be used instead of fixed pillars along with a positioning mechanism. The use of collapsible pillars provides an additional advantage of avoiding pillar projection when the cart is in a closed condition. FIG. 7A is a side perspective view of a cart 400 including a collapsible pillar 32 which has a telescopic structure with the first end 32a and the second end 32b be fixed to the platform 10 and the roof 20, respectively, to avoid pillar projection when the cart 400 is in a closed condition. FIG. 7B is a cross-sectional view of a cart 400’ in an opened condition. FIG. 7C is a cross-sectional view of the cart 400’ of FIG. 7B in a closed condition. The collapsible pillar 32 includes a telescopic leg arrangement 34 including a slider mechanism such that the first end 32a is received by the leg 34 and the second end 32b is fixed to the roof 20 to avoid pillar projection when the cart 400’ is in a closed condition as shown in FIG. 7C. FIG. 7B also shows the sloped roof 20 with an angle with respect to the platform 10 in a range from 5 degrees to 15 degrees.

FIG. 7D is a side perspective view of a cart 140, according to one embodiment. The roof 20 can be moved upward and downward with respective to the platform 10 between an open position (FIG. 7E) and a closed position (FIG. 7F) to adjust the height of the conditioned space between. In the embodiment depicted in FIG. 7D, a winch or worm gear mechanism 142 is connected to an edge 10a of the platform 10. A pulley 144 is connected to an edge 20a of the roof 20, carrying a flexible rope 143 connected to the winch or worm gear mechanism 142. A user can manually operate the winch or worm gear mechanism 142 to move the roof 20 upward and downward to facilitate the opening and closing of the cart 140. One or more scroll wheels 146 are provided on the edge 20a of the roof 20 to guide the movement of the edge 20a along the pillars 32 upward and downward. In the embodiment depicted in FIG. 7D-7F, the gearing system, including the winch or worm gear mechanism 142, the pulley 144, the rope 143, and the scroll wheels 146, can be provided on each of the opposite sides of the cart 140. Two users can cooperate on each side to use the winch or worm gear mechanism 142 to manually move the roof 20 upward and downward.

FIG. 7G is a side perspective view of a cart 150, according to one embodiment. FIG. 7H illustrates an enlarged portion view of the cart 150. The roof 20 can be moved upward and downward with respective to the platform 10 between an open position (see, e.g., FIG. 7B or 7E) and a closed position (FIG. 7C or 7F) to adjust the height of the conditioned space between the roof 20 and the platform 10. In the embodiment depicted in FIGS. 7G-H, a pin lock mechanism 152 is provided to manually lock the roof 20 on the pillars 32 when the cart 150 is at the open position. The pin lock mechanism 152 may include a sleeve 153 connected to the edge 20a of the roof 20 to receive the pillar 32. The sleeve 153 and the pillar 32 may have a cross-sectional shape matched with each other, such as, e.g., a square shape, a round shape, etc. A locking pin 155 can insert into aligned holes of the sleeve 153 and the pillar 32 to lock the roof 20 in place. It is to be understood that the pillars 32 may have one or more holes located at different heights such that the pin lock mechanism 152 can lock the roof 20 at the corresponding heights with respect to the platform 10.

In various embodiments described herein, charged water can be provided to sprinkle or spray (e.g., in a mist form) on items (e.g., perishables) disposed within the conditioned space of an apparatus (e.g., a cart). In some cases, at fixed interval of time, water mist can be automatically sprayed on items or it can also be manual actioned by a user (e.g., a vendor). Water to generate mist can be cooled radiatively by the cart itself, or can be a cold water to be filled to a charged water generating system. Distribution or spraying of charged water can be implemented by various methods and systems described herein. The charged water spray increases the shelf life of the perishables, reduces weight loss, enables evaporative cooling, and maintains freshness for longer.

Production of charged water from a passively cooled thermal storage can reduce weight loss and increase shelf life by controlling microbial growth. In some cases, production of charged water can be remotely in bulk or on location, providing the same to a user (e.g., a vendor) spray on the produce. In some cases, cold fluid (e.g., water) from a cold fluid reservoir can be used to generate charged mist using a piezoelectric method, for spraying on the produce. The use of charged water can cool the produce as it evaporates, in addition to controlling microbial growth.

FIG. 8A is a cross-sectional view of an apparatus 500 including a charged water distribution mechanism 510, according to one embodiment. FIG. 8B is a cross-sectional view of the apparatus 500 including a charged water distribution mechanism, according to another embodiment. The charged water distribution mechanism 510 includes a water treatment component 512 to generate the charged water, and a water delivery component 514 to deliver the charged water into the conditioned space 3. In the depicted embodiment of FIG. 8 A, the water delivery component 514 includes a mist delivery pipe 513 and an array of spray/spr inkle nozzles 515 distributed along the mist delivery pipe 513. In the depicted embodiment of FIG. 8B, a water delivery component 516 is provided centrally to provide the charged water in the conditioned space 3. An air curtain may be provided to help to distribute the charged water when it is sprayed or sprinkled via the array of spray/sprinkle nozzles 515. In some cases, the mist delivery pipe 513 may have a telescopic structure to allow it to be collapsible. In some cases, the mist delivery pipe 513 and/or water delivery component 514 may be tiltable or rotatable within the conditioned space 3. The height of the charged water distribution mechanism 510 can be adjusted along a vertical axis of the apparatus 500 as shown in FIG. 8A. It is to be understood that a water distribution mechanism may include any fluid flow control mechanisms (e.g., inlets, outlets, valves, drainpipes, etc.) can be used to regulate the pressure, flow, distribution, and spray/sprinkle of the fluid into the conditioned space 3. In some cases, a fan or other air moving device can be provided to circulate the charged water.

In some cases, a water treatment component includes a charged water generator and an inbuilt water storage tank that uses both water shearing and a field charger. FIG. 8C is a schematic diagram of an exemplary water treatment component 512 including a charged water generator for creating an aerosol including negative ions from the condensate or water. The water treatment component 512 includes a bulk charging electrolytic unit 51 for a water bulk electrolysis process where voltage or current is applied, via a power source 53, e.g., a five-volt source, such as from a battery or a solar cell, to an electrochemical cell. Condensate or water may collect within the bulk charging unit to be generated into an aerosol. A piezoelectric mist generator 55, which includes two piezo transducers is also provided to the electrochemical cell to generate water mist by vibrating the condensate or water. The vibration shears and breaks up the condensate or water, which generates the aerosol, and negative ions, which may be in the form of ionized water droplets or vapor. The aerosol including the negative ions can pass through an electric field module 57 to generate super charged (e.g., both bulk and surface) water microdroplets 59, e.g., more negative ions. It is to be understood that the water treatment component 512 may include any suitable components or structures to generate charged water mist to be delivered to the conditioned space. In some cases, water can be provided from an inbuilt water storage tank of the water treatment component 512. In other cases, water can be delivered externally from a water source outside of the water treatment component 512. In various embodiments, an apparatus described herein includes a cooling and/or sanitization system configured to address heat and humidity issues within a conditioned space thereof. In some cases, a cooling and/or sanitization system includes a radiatively cooled fluid reservoir which provides a cold fluid that is, for example, at least 5°C lower than an ambient temperature. A fluid reservoir may be in the form of a tank which has its major thermalcontacting surface(s) at least partially made of a thermally conductive material such as, for example, a metal, a thermally conductive plastic, or other material that has high thermal conductive properties, to promote heat exchange. In some cases, a cooling and/or sanitization system may be integrated with a passive radiative cooling canopy (e.g., the roof 20 of FIGS. 1A, 2B) which provides radiative cooling at a level, for example, around 150 W/m². In some cases, a cooling and/or sanitization system includes a thermosyphon cooling mechanism integrated with a fluid reservoir and a radiative cooling canopy to reject heat from the items (e.g., perishables) within the conditioned space to an outer space. In some cases, a cooling and/or sanitization system includes a forced convective cooling of air underneath the canopy by utilizing the cold fluid. In some cases, a cooling and/or sanitization system may be integrated with a charged water distribution mechanism described herein. For example, the charged water distribution mechanism may produce charged water from a passively cooled thermal storage of the system to reduce weight loss and increase shelf life by controlling microbial growth.

FIG. 9A is a cross-sectional view of an apparatus 600 including a thermal storage tank 610 supported by the leg arrangement 34 for the pillars 32. The tank 610 is provided to store a cooling fluid 6 to provide cooling effect to items 4 (e.g., perishables) in thermal contact with the tank 610. The cooling fluid 6 may include water or one or more phase-change materials (PCMs) for thermal energy storage. The tank 610 has a bottom surface 612 where a radiative film 614 is disposed thereon such that the tank 610 can be radiatively cooled.

During daytime, the tank 610 is attached to the apparatus 600 where its upper surface 616 can serve as the platform 10 to provide cooling effect to the items 4 disposed thereon. In general, a surface serving as a platform surface to keep cargoes can have a good thermal conductivity to enhance heat exchange. The upper surface 616 of the tank 610 may include a thermally conductive material such as, e.g., a metal. In some cases, cooling spots/areas may be provided at selected locations of the upper surface 616, and other areas of the upper surface 616 may be covered by a thermally insulating material to improve cooling efficiency. A thermally insulating layer or material 618 is provided to cover the bottom surface 612 of the tank 610. The layer 618 includes a thermally insulating material (e.g., wood, plastic, fabric, foam, glass filler, paper board, etc.) to prevent convective ambient air heat gain and radiation from the space undeath the tank 610 (e.g., as indicated by the arrow 701 in FIG. 7B). The layer 618 can be fixed to the apparatus 600, or be attached to the tank 610 and removable therefrom. At night, the tank 610 can be flipped as shown in FIG. 9B such that its bottom surface 612 faces the sky to facilitate heat dissipation from the radiative film 614. In some cases, the tank 610 can be detached from the apparatus 600 and flipped for the radiative re-cooling purpose. In some cases, the tank 610 can be rotated to flip upside-down without being detached from the apparatus 600. For example, the platform 10 may include a rotation rod supported by a frame thereof, and the tank 610 can be at least partially slide out along the rotation rod and then be rotated to flip upside-down in the position as shown in FIG. 9B.

In some cases, a cooling system may have a dual-thermal-storage-tank design where a first tank may act as the roof, and a second tank may act as the platform. The roof tank can be provided with a radiative film facing the sky. The roof tank and the platform tank are in a fluid communication via, for example, a connection pipe. At night, a cooling fluid can be at the roof tank and get radiatively cooled via the radiative film on the upper surface of the roof. During daytime, the radiatively cooled fluid can be brought back to the platform tank to cool the items on the platform. Flow of the cooling fluid between the tanks can be a manual operation (e.g., through a hand pump or a physical activity). The fluid flow can also be by driven by an electrical pump.

FIG. 10A is a cross-sectional view of an apparatus 700 including a dual-tank cooling system in a first condition. FIG. 10B is a cross-sectional view of the apparatus 700 including the dual-tank cooling system of FIG. 10A in a second condition. The apparatus 700 includes a platform tank 710, and a roof tank 720 in fluid communication with the platform tank 710. The radiative film 24 is disposed on an upper surface of the roof tank 720. A thermally insulating layer or material can be provided to cover the bottom surface of the roof tank 710. The thermally insulating layer may include a thermally insulating material (e.g., wood, plastic, fabric, foam, glass filler, paper board, etc.) to prevent convective ambient air heat gain and radiation as indicated by the arrow 701 from the space underneath the tank 710, 720. The platform tank 710 is supported by the leg arrangement 34 and includes an upper surface 712 acting as the platform 10 which is in thermal contact with the supported items 4 (e.g., perishables such as fruit, leaf, vegetable, etc.). The upper surface 712 may include a thermal interface material (TIM, e.g., a thermally conductive material such as a metal, a thermal paste, a thermal tape, etc.) to enhance the cooling of the items 4. When the apparatus 700 is in an opened position as shown in FIG. 10A, the cooled fluid 6 (e.g., water or a phase change material) is disposed in the platform tank 710 to cool the items 4 on the platform 10 and emptied from the roof tank to provide air as an insulating barrier. The platform tank 710 further includes a bottom surface 714 which can be made of a thermally insulating material (e.g., wood, plastic, fabric, foam, glass filler, paper board, etc.) to prevent convective ambient air heat gain and radiation from the space underneath the platform tank 710. When the apparatus 700 is in a closed position as shown in FIG. 10B, the cooling fluid 6 is pumped (e.g., manually or by an electrical pump) via a fluid connection 102 from the platform tank 710 to the roof tank 720. The roof tank 720 has the radiative film 24 disposed on its upper surface 722 to provide radiative cooling to the fluid 6 in the roof tank 720. The cooled fluid 6 can be manually brought back to the platform tank 710 via a fluid connection 104 by gravity. Any suitable fluid flow control mechanisms (e.g., inlets, outlets, valves, drainpipes, etc.) can be used to regulate the flow or pressure of the fluid 6.

In some cases, a cooling system may further include a thermosyphon cooling mechanism. A typical thermosyphon cooling mechanism may include a source section where heat is delivered and a sink section where the heat is released. The thermosyphon cooling mechanism is charged by a pre-determined amount of an appropriate working fluid (e.g., a refrigerant such as, e.g., R-134A). The working fluid located in the source section evaporates and goes toward the sink section (e.g., by means of a pressure gradient), where the working fluid condenses, returning to the source section by means of, for example, gravity.

In some cases of the present disclosure, a tank with cooling fluid (e.g., water or a phase change material) can be provided as a platform to support and cool items (e.g., perishables) disposed thereon. The items transfer heat to the cooling fluid in the tank. Inside the tank, a source section of a thermosyphon cooling mechanism can be provided. The cooling fluid in the tank boils a refrigerant in the source section of the thermosyphon cooling mechanism, and the refrigerant vapor is transported to a sink section of the thermosyphon cooling mechanism. The sink section is in thermal contact with a radiative film which provides radiative cooling to condense the refrigerant vapor. The sink section and the radiative film can be assembled and act as a roof of an apparatus.

FIG. 11 A is a cross-sectional view of an apparatus 800 including a thermosyphon cooling mechanism 110, according to one embodiment. The apparatus 800 further includes a platform tank 810 which may be similar to or different from the platform tank 710 of FIGS. 10A and 10B. The platform tank 810 is supported by the leg arrangement 34, and includes an upper surface 812 acting as the platform 10 which is in thermal contact with the supported items 4 (e.g., perishables such as fruit, leaf, vegetable, etc.). The thermosyphon cooling mechanism 110 includes a source section 112 disposed inside the platform tank 810 underneath the upper surface 812. The cooling fluid 6 in the platform tank 810 receives heat from the items 4 on the upper surface 812 and boils a refrigerant in the source section 112 and the refrigerant vapor is transported, via an adiabatic channel section 114, to a sink section 116 of the thermosyphon cooling mechanism 110 disposed at the roof 20. The radiative film 24 is disposed on the upper surface 22 of roof 20. The sink section 116 further includes an insulation layer 118 provided on the side of the roof 20 opposite the radiative film 24. The sink section 116 and the radiative film 24 are assembled and act as the roof 20. The sink section 116 is in thermal contact with the radiative film 24 to condense the refrigerant vapor. The cooled refrigerant then returns to the source section 112 via the adiabatic channel section 114 to absorb heat from the heated fluid 6 in the platform tank 810. In some cases, a thermal interface material (TIM, e.g., a thermally conductive material such as a metal, a thermal paste, a thermal tape, etc.) can be disposed between the radiative film 24 and the sink section 116 to enhance the heat exchange therebetween.

FIG. 1 IB is a cross-sectional view of a thermosyphon cooling mechanism 160, according to one embodiment. The thermosyphon cooling mechanism 160 is applied to conduct a heat exchange with the radiative film/layer 24 that may be included in any apparatus (e.g., a cart) described herein. It is to be understood that one or more thermosyphon cooling mechanisms 160 can be applied to an apparatus (e.g., a cart). The thermosyphon cooling mechanism 160 includes one or more source sections 162 disposed at least partially inside the respective thermal reservoirs 163. A controller 161 can control the circulating, via a pump 165 and one or more valves 167, a process fluid from one or more of the thermal reservoirs 163 to receive heat from the surface/object 64 (e.g., the items 4 on the platform 10 in FIG. 1A). The heated process fluid returns to the respective thermal reservoirs 163 to heat a working fluid in the respective source sections 162. The controller 161 can control, via one or more of the valves 167, the flow of the heated working fluid from the respective thermal reservoirs 163, via an adiabatic channel section 114, to a sink section 166 of the thermosyphon cooling mechanism 160 in thermal contact with the radiative film/layer 24. The sink section 166, in thermal contact with the radiative film/layer 24, can cool the working fluid which returns to the respective source sections 162 via the adiabatic channel section 114. In some cases, a thermal interface material (TIM, e.g., a thermally conductive material such as a metal, a thermal paste, a thermal tape, etc.) can be disposed between the radiative film/layer 24 and the sink section 166 to enhance the heat exchange therebetween.

In the embodiment depicted in FIG. 1 IB, the controller 161 can determine, based on the temperature difference between a source section and a sink section, which source section 162 to be operated. While two source sections 162 are illustrated in FIG. 1 IB, it is to be understood that other numbers of source sections can be used. It is also to be understood that multiple sink sections can be used to remove heat from one or more surfaces/objects. The use of a controller and a pump may be optional. The thermal reservoirs may be a surface/object from which heat is to be removed. A source/sink section of thermosyphon may be partially or completely encapsulated in a thermal reservoir, to which the extent can be controlled.

In some cases, a cooling system may further include a forced convective cooling of air underneath the roof or canopy by utilizing a cold fluid, where a thermal energy storage tank is located at the roof to receive a cooling fluid, and an air duct is in thermal contact with the tank to exchange heat. A radiative film is disposed on an upper surface of the tank to provide radiative cooling to the fluid in the tank which is in heat exchange with air in the air duct. The cooled air can be delivered to a conditioned space underneath the roof.

FIG. 12 is a side view of an apparatus 900 including a cooling system 910 disposed at the roof 20. The cooling system 910 includes a thermal energy storage tank 912 as a roof tank and a radiative film 24 disposed on the upper surface 22 of the roof 20. The tank 912 can have its major thermal-contacting surface(s) at least partially made of a thermally conductive material such as, for example, a metal, a thermally conductive plastic, or other material that has high thermal conductive properties, to promote heat exchange. An air duct 914 is disposed on the side of the tank 912 opposite the radiative film 24. Fresh air from the ambient is sucked through or blown into a first end 914a of the air duct 914 via a fan 913. The air duct 914 is in thermal contact with a bottom surface of the tank 912 where heat exchange takes place between the air in the air duct 914 and the radiatively cooled fluid in the tank 912. In some cases, a thermal interface material (TIM, e.g., a thermally conductive material such as a metal, a thermal paste, a thermal tape, etc.) may be applied to enhance the heat exchange between the tank 912 and the air duct 914. A thermally insulating layer or material (e.g., wood, plastic, fabric, foam, glass filler, paper board, etc.) can be applied on a bottom surface of the air duct 914 to prevent convective ambient air heat gain and radiation from the space underneath the air duct 914. The cooled air is then blown out of the second end 914b of the air duct 914 into the conditioned space to keep the items 4 (e.g., perishables) on the platform 10 cool. The fixed or detachable type storage box 7 is provided with a locking option on the bottom of the platform 10. In some cases, a fan or other air moving device can be provided to circulate the cooled air and/or deliver the cooled air to desired locations such as indicated by the arrow 901.

It is to be understood that any components of a cooling and/or sanitization system described herein can be combined in any suitable manner. For example, in some cases, a cooling and/or sanitization system may include one or more of a platform tank to receive a cooling fluid and to keep items on its upper surface, a thermosyphon cooling mechanism, a forced convective cooling mechanism of air underneath the roof/canopy by utilizing a cold fluid, a charged water distribution mechanism, etc.

Aspects:

It is appreciated that any one of aspects can be combined with other aspect(s).

Aspect 1 is an apparatus to provide a conditioned space, the apparatus comprising: a roof positioned to provide a shielding to the conditioned space underneath the roof; and a radiative film disposed on an upper surface of the roof and configured to provide radiative cooling to the conditioned space.

Aspect 2 is the apparatus of aspect 1, further comprising one or more platforms positioned below the roof to define the conditioned space.

Aspect 3 is the apparatus of aspect 1 or 2, further comprising a positioning mechanism configured to move at least one of the roof and the one or more platforms upward and downward between an open position and a closed position to adjust a height of the conditioned space. Aspect 4 is the apparatus of any one of aspects 1-3, further comprising a plurality of collapsible pillars connecting the roof to the platform.

Aspect 5 is the apparatus of any one of aspects 1 -4, further comprises a collapsible overhang that is attached to the roof.

Aspect 6 is the apparatus of any one of aspects 2-5, wherein the one or more platforms further include a cutout on a side thereof.

Aspect 7 is the apparatus of any one of aspects 1 -6, wherein the roof further includes a sealing mechanism over a bottom edge therefor.

Aspect 8 is the apparatus of aspect 7, wherein the sealing mechanism includes a rubber bead.

Aspect 9 is the apparatus of any one of aspects 1-8, wherein the upper surface of the roof is sloped, optionally, the upper surface includes a structured surface.

Aspect 10 is the apparatus of any one of aspects 3-8, wherein the positioning mechanism includes a scissor mechanism.

Aspect 11 is the apparatus of aspect 10, wherein the scissor mechanism includes first and second supports pivotally connected at a riveted join in a crisscross “X” pattern.

Aspect 12 is the apparatus of aspect 10 or 11, wherein the scissor mechanism further includes a moving mechanism to move a first end of the first support, and a mounting block to pivotally connected to a second end of the first support.

Aspect 13 is the apparatus of aspect 12, wherein the moving mechanism includes a handle and a lead screw that rotates by turning the handle.

Aspect 14 is the apparatus of any one of aspects 10-13, wherein the scissor mechanism further includes a slider to guide a first end of the second support, and a mounting block to pivotally connected to a second end of the second support.

Aspect 15 is the apparatus of any one of aspects 3-14, wherein the positioning mechanism further includes a bellow to enclose the positioning mechanism.

Aspect 16 is the apparatus of any one of aspects 3-15, wherein the positioning mechanism includes a chain and sprocket mechanism.

Aspect 17 is the apparatus of any one of aspects 1-16, further comprising one or more wheels. Aspect 18 is the apparatus of any one of aspects 1-17, further comprising one or more storage boxes. Aspect 19 is the apparatus of any one of aspects 1-18, further comprising a charged water distribution mechanism configured to sprinkle or spray charged water into the conditioned space. Aspect 20 is the apparatus of aspect 19, wherein the charged water distribution mechanism further includes a water treatment component to generate the charged water, and a water delivery component to deliver the charged water, optionally, the water treatment component further includes a charged water generator and an inbuilt water storage tank.

Aspect 21 is the apparatus of any one of aspects 1-20, further comprising a cooling system to provide a cold fluid.

Aspect 22 is the apparatus of aspect 21, wherein the cooling system further includes a rotatable thermal storage tank connected to the platform.

Aspect 23 is the apparatus of aspect 22, wherein the rotatable thermal storage tank further includes a second radiative film disposed on a bottom surface thereof.

Aspect 24 is the apparatus of any one of aspects 21-23, wherein the cooling system further includes a platform tank, and a roof tank in fluid communication with the platform tank, the radiative film being disposed on an upper surface of the roof tank.

Aspect 25 is the apparatus of any one of aspects 21-24, wherein the cooling system further includes a thermosyphon cooling mechanism.

Aspect 26 is the apparatus of any one of aspects 21-25, wherein the cooling system further includes a thermal energy storage tank connected to the roof, and an air duct in thermal contact with the thermal energy storage tank.

Aspect 27 is the apparatus of aspect 26, wherein the radiative film is disposed on an upper surface of the thermal energy storage tank to provide radiative cooling to a fluid in the thermal energy storage tank which is in heat exchange with air in the air duct.

Aspect 28 is the apparatus of aspect 26 or 27, wherein the air duct is thermally insulated.

Aspect 29 is the apparatus of any one of aspects 26-28, further comprising a fan configured to suck or blow air through or into the air duct.

Aspect 30 is the apparatus of any one of aspects 1-29, wherein the roof further includes a door, and at least a portion of the upper surface is openable along with the door.

Aspect 31 is the apparatus of any one of aspects 1-30, further comprising a winch mechanism to move the roof upward and downward. Aspect 32 is the apparatus of any one of aspects 1-31, further comprising a pin lock mechanism to lock the roof at a predetermined height.

The terminology used in this specification is intended to describe particular embodiments and is not intended to be limiting. The terms “a,” “an,” and “the” include the plural forms as well, unless clearly indicated otherwise. The terms “comprises” and/or “comprising,” when used in this specification, specify the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components. With regard to the preceding description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size, and arrangement of parts without departing from the scope of the present disclosure. This specification and the embodiments described are exemplary only, with the true scope and spirit of the disclosure being indicated by the claims that follow.

Claims

CLAIMS What is claimed is:

1. An apparatus to provide a conditioned space, the apparatus comprising: a roof positioned to provide a shielding to the conditioned space underneath the roof; and a radiative film disposed on an upper surface of the roof and configured to provide radiative cooling to the conditioned space.

2. The apparatus of claim 1 , further comprising one or more platforms positioned below the roof to define the conditioned space.

3. The apparatus of claim 1 or 2, further comprising a positioning mechanism configured to move at least one of the roof and the one or more platforms upward and downward between an open position and a closed position to adjust a height of the conditioned space.

4. The apparatus of any one of claims 1-3, further comprising a plurality of collapsible pillars connecting the roof to the platform.

5. The apparatus of any one of claims 1-4, further comprises a collapsible overhang that is attached to the roof.

6. The apparatus of any one of claims 2-5, wherein the one or more platforms further include a cutout on a side thereof.

7. The apparatus of any one of claims 1-6, wherein the roof further includes a sealing mechanism over a bottom edge therefor.

8. The apparatus of claim 7, wherein the sealing mechanism includes a rubber bead.

9. The apparatus of any one of claims 1-8, wherein the upper surface of the roof is sloped, optionally, the upper surface includes a structured surface.

10. The apparatus of any one of claims 3-8, wherein the positioning mechanism includes a scissor mechanism.

11. The apparatus of claim 10, wherein the scissor mechanism includes first and second supports pivotally connected at a riveted join in a crisscross “X” pattern.

12. The apparatus of claim 10 or 11, wherein the scissor mechanism further includes a moving mechanism to move a first end of the first support, and a mounting block to pivotally connected to a second end of the first support.

13. The apparatus of claim 12, wherein the moving mechanism includes a handle and a lead screw that rotates by turning the handle.

14. The apparatus of any one of claims 10-13, wherein the scissor mechanism further includes a slider to guide a first end of the second support, and a mounting block to pivotally connected to a second end of the second support.

15. The apparatus of any one of claims 3-14, wherein the positioning mechanism further includes a bellow to enclose the positioning mechanism.

16. The apparatus of any one of claims 3-15, wherein the positioning mechanism includes a chain and sprocket mechanism.

17. The apparatus of any one of claims 1-16, further comprising one or more wheels.

18. The apparatus of any one of claims 1-17, further comprising one or more storage boxes.

19. The apparatus of any one of claims 1-18, further comprising a charged water distribution mechanism configured to sprinkle or spray charged water into the conditioned space.

20. The apparatus of claim 19, wherein the charged water distribution mechanism further includes a water treatment component to generate the charged water, and a water delivery component to deliver the charged water, optionally, the water treatment component further includes a charged water generator and an inbuilt water storage tank.

21. The apparatus of any one of claims 1-20, further comprising a cooling system to provide a cooling fluid.

22. The apparatus of claim 21, wherein the cooling system further includes a rotatable thermal storage tank connected to the platform.

23. The apparatus of claim 22, wherein the rotatable thermal storage tank further includes a second radiative film disposed on a bottom surface thereof.

24. The apparatus of any one of claims 21-23, wherein the cooling system further includes a platform tank, and a roof tank in fluid communication with the platform tank, the radiative film being disposed on an upper surface of the roof tank.

25. The apparatus of any one of claims 21-24, wherein the cooling system further includes a thermosyphon cooling mechanism.

26. The apparatus of any one of claims 21-25, wherein the cooling system further includes a thermal energy storage tank connected to the roof, and an air duct in thermal contact with the thermal energy storage tank.

27. The apparatus of claim 26, wherein the radiative film is disposed on an upper surface of the thermal energy storage tank to provide radiative cooling to a fluid in the thermal energy storage tank which is in heat exchange with air in the air duct.

28. The apparatus of claim 26 or 27, wherein the air duct is thermally insulated.

29. The apparatus of any one of claims 26-28, further comprising a fan configured to suck or blow air through or into the air duct.

30. The apparatus of any one of claims 1-29, wherein the roof further includes a door, and at least a portion of the upper surface is openable along with the door.

31. The apparatus of any one of claims 1-30, further comprising a winch mechanism to move the roof upward and downward.

32. The apparatus of any one of claims 1-31, further comprising a pin lock mechanism to lock the roof at a predetermined height.