US20160109186A1

US20160109186A1 - Apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vehicles, cold rooms and the like

Info

Publication number: US20160109186A1
Application number: US14/888,652
Authority: US
Inventors: Michal Kolda; Markéta KOPECKA; Michal Hegar; Václav RAJTMAJER; Pavel Houdek; Lubos Forejt; Alberto Ghiraldi
Original assignee: Thermo King Corp
Current assignee: Thermo King Corp
Priority date: 2013-05-02
Filing date: 2014-05-02
Publication date: 2016-04-21
Also published as: CN105593134A; EP2992281A4; EP2991916A1; WO2014193600A1; WO2015012932A1; CN105579797A; EP2992281A1; US20160109187A1

Abstract

An apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vehicles, cold rooms and the like, including one or more thermal storage devices, each including a housing defining a cavity for holding a phase change material. The cavity contains a heat exchanger that may be supplied with a heat exchange fluid. The housing includes a substantially flat wall portion and a heat transfer enhanced wall portion. The apparatus includes ventilator in communication with the thermal storage device.

Description

FIELD

The present disclosure relates to an apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vans, cold rooms and the like.

BACKGROUND

The transport and distribution of perishable goods, in particular foodstuffs, requires that they be kept at temperatures that meet ATP standards. Examples of ATP standards include, but are not limited to, Class A, for “chilled” goods, and Class C, for “frozen” goods. For example, some containers can maintain temperatures between about −35° C. and about 21° C.
There are currently two alternatives for controlling the temperature inside vehicles for transporting the perishable goods: installation of eutectic plates in the refrigerated container or use of cooling apparatus powered by the engine of the vehicle or having a separate diesel generator.
The use of eutectic plates in the refrigerated containers of the vehicle has drawbacks owing to the inherent characteristics of the technologies used, including:
a) the eutectic solutions used are based on saline;
b) they are corrosive and not compatible with aluminum, and thus require the use of carbon steel or stainless steel, having a typical heat conductivity of 45 W/m° C. and a specific weight of 7.9 tonnes/m³, as opposed to the heat conductivity of 221 W/m° C. and specific weight of 2.7 tonnes/m³of aluminum, with the consequent increase in weight and reduction in heat conductivity and the impossibility of forming finned surfaces either on the side exposed to the air or the side in contact with the heat-conducting fluid;
c) it is impossible to regulate the temperature inside the vehicle, leading to over-use of capacity at the start of the journey, and it is impossible to respond proportionally to thermal charging;
d) installation in the refrigerated container is difficult and laborious, as they have many components that require complex and costly piping, and a structure must be incorporated in the isothermal container to allow the plates to be fitted, the plates typically covering the whole of the ceiling and end wall;
e) they are unstable over time and tend to wear out owing to separation between the components of the solutions used and, as it is not possible to replace the solutions, the whole plate must be replaced;
f) they cannot be used in cold climates, where it is necessary to heat the container of the vehicle as the external temperature falls well below 0° C., to maintain the above-zero temperatures necessary for the storage of “chilled” goods;
g) they become progressively coated in frost, with a consequent reduction in efficiency and increase in tare and, as they do not include automatic defrosting means, it is therefore necessary to put the vehicle out of use for periods of between 24 and 72 hours to defrost the actual plates.
As regards the use of cooling apparatus powered by the vehicle engine, or by an independent diesel generator, the main drawbacks relate to:
a) high energy consumption and associated pollution due to CO₂emissions;
b) noise levels;
c) gradual build-up of ice in the evaporants and consequent drop in efficiency if the doors are opened frequently;
d) break in the cold chain when the vehicle stops, if there is no independent generator;
e) they require complex and laborious installations, and costly and constant maintenance, in specialized centers.

SUMMARY

The present disclosure aims to provide an apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vehicles and the like.
The embodiments described herein can provide:
a) transport of perishable “chilled” or “frozen” goods with a high level of reliability and energy efficiency;
b) lower running and maintenance costs;
c) lower impact on the environment;
d) transport of “chilled” or “frozen” goods in both hot climates and extremely cold climates where it may be required to warm the isothermal container to prevent damage to chilled goods owing to low external temperatures;
e) quick and easy defrosting making use of times when the vehicle stops, without having to take the vehicle out of use;
f) simplified, more rapid and less costly installation in a refrigerated container of a van;
g) optimized heat exchange, considerably increasing thermal efficiency and reducing energy wastage.
The above aim, and the related objectives and others that will become more apparent below, are achieved by an apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vehicles, cold rooms and the like, including one or more thermal storage devices, each including a housing defining a cavity for holding a phase change material, the cavity containing a heat exchanger that may be supplied with a heat transfer fluid, characterized in that the housing has a first wall with a substantially flat surface and a second wall, opposite the first wall, with a surface that is at least partially finned, a ventilator being associated with the one or more thermal storage devices.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages will become clear from the description of three particular, but non-limiting, embodiments of an apparatus for the storage of refrigerated or frozen goods, in particular for refrigerated van containers or the like, illustrated by way of non-limiting example with the aid of the attached drawings, in which:

FIG. 1 is an end-on view of a first embodiment of an apparatus for the storage of refrigerated or frozen goods, according to the disclosure, placed inside a refrigerated container.

FIG. 2 is a side view of a refrigerated container, containing the apparatus of FIG. 1, according to the disclosure.

FIG. 3 is a side view of the apparatus of FIG. 1, according to the disclosure, inside the refrigerated container.

FIG. 4 is an end-on view of a thermal storage device included in the apparatus of FIG. 1.

FIG. 5 is a side view of the thermal storage device of FIG. 4.

FIG. 6 is a plan view from above of the thermal storage device of FIG. 4.

FIG. 7 is a view in section, along the line VII-VII, of the thermal storage device shown in FIG. 4.

FIG. 8 is an end-on view of a second embodiment of an apparatus for the storage of refrigerated or frozen goods, according to the disclosure, placed inside a refrigerated container.

FIG. 9 is a side view of the apparatus of FIG. 8, according to the disclosure, inside the refrigerated container.

FIG. 10 is an end-on view of a thermal storage device included in the apparatus of FIG. 8.

FIG. 11 is a side view of the thermal storage device of FIG. 10.

FIG. 12 is a plan view from below of the thermal storage device of FIG. 10.

FIG. 13 is a view in section, along the line XIII-XIII, of the thermal storage device shown in FIG. 12.

FIG. 14 is an end-on view of a third embodiment of an apparatus for the storage of refrigerated or frozen goods, according to the disclosure, placed inside a refrigerated container.

FIG. 15 is a side view of the apparatus of FIG. 14, according to the disclosure, inside the refrigerated container.

FIG. 16 is view in section of the apparatus shown in FIG. 14, along the line XVI-XVI.

FIG. 17 is an end-on view of a thermal storage device included in the apparatus of FIG. 14.

FIG. 18 is a side view of the thermal storage device of FIG. 17.

FIG. 19 is a plan view from above of the thermal storage device of FIG. 17.

FIG. 20 is a view in section, along the line XX-XX, of the thermal storage device shown in FIG. 19.

DETAILED DESCRIPTION

With reference to the abovementioned figures, the apparatus 1 for the storage of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated transport vehicles, cold rooms and the like, includes one or more thermal storage devices 3, each including a housing 5 defining a cavity 7 designed to hold a phase change material. The cavity 7 contains a heat exchanger 9 that may be supplied with a heat transfer fluid.
According to an embodiment, the housing 5 has a first wall 11 with a substantially flat surface and a second wall 13, opposite the first wall 11, with a surface that is at least partially finned. The housing 5 includes a ventilator 15 associated with the thermal storage device 3.
The cavity 7 of each thermal storage device 3 houses a heat exchanger 9, which can have a double U-shaped tubular profile 90, inside which there flows a heat transfer fluid. The heat exchanger 9 is immersed in a phase change material and is capable of cooling, or alternatively heating, if required, the phase change material.
The double U-shaped tubular profile 90 can have an external surface 91, in contact with the phase change material, which is substantially smooth, and an internal surface 92, in contact with the heat transfer fluid, which includes a plurality of fins, to promote the exchange of heat. The U-shaped tubular profile 90 can include a flat structure 93 that connects, also thermally, the two, upward and downward, sections of the tubular elements of the U-shaped profile. The flat structure 93, immersed in the phase change material, has a ratio between the surface on the phase change material side and the surface on the heat transfer fluid side corresponding to the respective heat exchange coefficients. The flat structure 93 also has ends 95 that may be inserted in corresponding guides 94 formed on the inside surface of the housing 5 for fitting the heat exchanger 9 inside the housing 5 of the thermal storage device 3.
In an embodiment, the phase change material can include any phase change material having a solid-liquid transition occurring between about 0° C. and about −32° C. In an embodiment, the phase change material may be selected from the group including:

- hydrogen peroxide in concentrations of between about 0% and about 35%;
- n-decane.

In one embodiment, hydrogen peroxide in concentrations of between about 1.5% and about 6%, i.e., from about 5 to about 20 volumes, can have a solid-liquid transition temperature substantially in the range between about −1° C. and about −6° C., and can be used for the storage of “chilled” goods.
In another embodiment, hydrogen peroxide in concentrations of between about 25% and about 35%, i.e. from about 80 to about 116 volumes, can have a solid-liquid transition temperature substantially in the range between about 25° C. and about −32° C., and can be used for the storage of “frozen” goods, corresponding to Class C of the ATP standard.
In one embodiment, n-decane can have a solid-liquid transition temperature of about −29.5° C. and can be used for the storage of “frozen” goods.
In one embodiment, hydrogen peroxide in concentrations of between about 1.5% and about 10% can be stabilized and characterized by a release of oxygen of less than about 3% of the oxygen content per year, equivalent to less than about 90 liters of O₂for every about 200 liters of phase change material, corresponding to about 90/365 of a liter per day, amounting to a tiny fraction of the volume of a transport vehicle using thermal storage means of this size which, typically, can have a volume of greater than about 10 m³.
In another embodiment, hydrogen peroxide in concentrations of between about 25% and about 35% is characterized by a release of oxygen of less than about 3% of the oxygen content per year, equivalent to less than about 270 liters of O₂for every about 200 liters of thermal storage liquid, corresponding to about 270/365 of a liter per day, amounting to a tiny fraction of the volume of a vehicle using thermal storage means of this size which, typically, has a volume of greater than about 10 m₃.
In some embodiments, the above thermal storage liquids can be non-flammable in the configuration used herein, compatible with aluminum, approved for use in indirect contact with foodstuffs, eco-friendly and highly stable.
The housing 5 of each thermal storage device 3, and the heat exchanger 9, can be made of aluminum, for example by extrusion. Indeed, the above phase change materials held in the cavity 7 of the housing 5 are not corrosive to aluminum, unlike some saline solutions used in known eutectic plates. Furthermore, compared to other types of material, aluminum can have a heat conductivity of about 221 W/m° C. and a specific weight of about 2.7 tonnes/m³, as opposed to a heat conductivity of about 45 W/m° C. and specific weight of about 7.9 tonnes/m³for steel, or a heat conductivity of about 0.1 W/m° C. and specific weight of about 1.1 tonnes/m³for plastic.
FIGS. 1-3, 8-9, and 14-16 show a refrigerated van container 100, including the apparatus 1 for the storage of refrigerated or frozen goods. The apparatus 1 is positioned adjacent to the end wall 102 of the container 100, but not attached to the end wall 102, and raised off the floor 104 of the container 100. The ventilator 15 is arranged at the top of the apparatus 1, near the ceiling 106 of the container 100. The second wall 13, the wall of the housing 5 with an at least partially finned surface, faces the end wall 102, while the first wall 11, the wall with a substantially flat surface, faces the internal space 112 of the container 100, where the goods are stored. The ventilator 15 can generate an airflow, indicated by the arrow 108, that passes between the floor 104 and the apparatus 1, enters the gap 110 created between the apparatus 1 and the end wall 102 of the container 100, skimming the second wall 13, and in particular the at least partially finned surface, and passes through the ventilator 15, before being dispersed in the internal space 112 of the container 100.
In particular, the wall 11 with a substantially flat surface can exchange heat by natural convection. The wall 13 with an at least partially finned surface makes, with the end wall 102 of the container 100, a channel for the forced, regulated and controlled passage of an airflow generated by the ventilator 15, thereby promoting heat exchange.
In one embodiment, the distance between the end wall 102 and the wall 13 of the thermal storage device 3 can be between about 4 and about 10 centimeters.
In one embodiment, it is possible to control the power of the ventilator 15, so as to be able to adjust the airflow 108 passing through the latter, within a range between about 0 and about 12 meters per second. Controlling the speed of the airflow passing along the gap 110 makes it possible to control the entire heat exchange between the air in forced circulation and the wall 13 with an at least partially finned surface. The ventilator 15 can include one or more DC fans.
The apparatus 1 may include a temperature sensor 30 for measuring the temperature inside the container 100, and thus control the ventilator 15 to increase or reduce the forced circulation of air, and hence increase or reduce the exchange of heat between the apparatus 1 and the internal space 112 of the container 100.
Use of the heat energy stored in the apparatus 1 may be optimized by, for example, the interaction of two factors, namely:

- adjustment of the forced flow of air in the gap between the apparatus 1 and the end wall 102, and
- the characteristic heat conductivity of the apparatus 1 itself, which is designed in such a way that the ratio of the heat exchange capacity of the flat surface with respect to the finned surface may range from about 1:2 to about 1:100.

The apparatus 1 includes a protective casing 21 that houses and protects the hydraulic connections for the heat exchangers 9 of each thermal storage device 3. The hydraulic connections of each thermal storage device 3 include an inlet connection 210 for the supply of the heat transfer fluid, whether gas or liquid, and an outlet connection 212, for suction of the heat transfer fluid. Inside the protective casing 21, the inlet connection 210 and outlet connection 212 for each thermal storage device 3 are fitted each to one of two separate conduits that can be accessed from outside the container 100 via an external connector 214, for connecting up a thermal charger, or refrigeration/heating unit, such as a DC or AC compressor. According to the first embodiment of the apparatus 1, shown in FIGS. 1-7, the thermal storage device 3 is arranged with the hydraulic connections 210 and 212 of the heat exchangers 9 at the bottom. Specifically, the protective casing 21 is positioned underneath the set of thermal storage device 3.
According to this embodiment, the housing 5 of each thermal storage device includes, at the top, a closable hole 51, visible in FIG. 6, for pouring in and refilling in the event of replacement of the phase change material, thereby also making it possible to change the class of refrigeration of the vehicle, taking it from Class C to Class A, for example, when the isothermal structure of the vehicle has deteriorated to the extent that it is not possible to renew ATP certification for the original classification.
Such an arrangement, with the hydraulic connections at the bottom, may be selected in the case of the use of a phase change material which, in the transition from a liquid to a solid, tends to expand, since it reduces the risks of the formation of pockets of liquid-phase phase change material which, because the phase change material does not freeze in the correct sequence, cannot drain off, and freeze later, giving rise to critical/destructive pressures. In other words, by supplying the thermal storage device from only one side, the lower side thereof, the sequence of freezing of the phase change material is such that the liquid freezes gradually, and uniformly, from the bottom up and from the center towards the sides, to allow the part which is still liquid to move upwards, thus preventing the formation of pockets of liquid that, when they later freeze, give rise to destructive pressure levels. Moreover, to further prevent such risks and avoid uncontrolled increases in pressure, a free expansion volume is left inside the housing 5, at a rate of between about 5% to about 15% of the volume taken up by the phase change material. A further measure would be to place a relief valve at the top of the housing 5, to let off excess pressure owing to dilation when passing from one state to the other, or owing to the release of oxygen over time by the hydrogen peroxide.
In the second embodiment, shown in FIGS. 8-13, and in the third embodiment, shown in FIGS. 14-20, the thermal storage device 3 is arranged with the hydraulic connections 210 and 212 for the circuit of the heat exchanger 9 at the top, and the protective casing 21 is also positioned at the top of the apparatus 1. This arrangement may be selected in the case of the use of a phase change material that contracts in the liquid-solid transition phase. As in the first embodiment of the apparatus 1, in the second and third embodiments, the closable hole 51 is made at the top of the housing 5.
In all the embodiments of the apparatus 1 shown, there are members 120 for securing the apparatus 1 to the end wall 102 of the container, and members 122 for supporting the apparatus 1 on the floor 104, so that the apparatus is raised off the floor 104. The apparatus 1 also includes protective bars 124, facing the internal space 112 of the container 100, to prevent the apparatus 1 from being damaged by goods shifting inside the container 100.
As shown in FIGS. 14-20, relating to the third embodiment of the apparatus 1, the housing 5 of each thermal storage device 3 includes a conduit 17 for the passage of a heat transfer fluid associated with at least one of the first, substantially flat, wall 11 and the second wall 13 with an at least partially finned surface of the housing 5. The passage conduit 17 can be associated with the second wall 13. The heat transfer fluid is capable of heating the wall of the housing 5, to defrost it rapidly and efficiently. Said passage conduit 17 forms part of a defrosting circuit including an upper hydraulic branch 170 and a lower hydraulic branch 172, and it is accessible from outside the container 100, via the external connector 214. To promote the exchange of heat between the heating liquid and the heat-conducting material of which the passage conduit 17 is made, the internal surface of the passage conduit 17 may have internal fins 175.
The external connector 214 may thus include various types of connections, all of which are generally quick-connections, for connecting, for example, the circuit of the thermal charger and therefore for the entry of the heat transfer fluid, or for connecting the defrosting circuit and therefore for the entry of the heat transfer fluid. Said external connector 214 may further include electrical connections for connecting to the temperature sensor 30 and the ventilator 15, for the purpose of monitoring the electrical peripherals.
The thermal charger may include a cooling compressor and the relevant accessories, and can:

- cool the heat transfer fluid to the temperature required for the phase change material to change state, typically to temperatures of about −5/about −15° C. for the Class A version and about −15/about −40° C. for the Class C version;
- pump and circulate the fluid inside the thermal storage device through the circuit to which it is connected by the quick-connections for supply and suction;
- heat the fluid for rapid defrosting, pumping it and circulating it to defrost the surface of the thermal storage device;
- heat the phase change material so that the Class A version can operate in winter conditions.

The apparatus 1 may include, in a modular manner, as many thermal storage devices 3 as necessary, according to the dimensions of the container 100 and the required thermal performance.
The operation of the apparatus for the storage of refrigerated or frozen goods is described below.
If the external temperature is above the refrigeration or freezing temperature required inside the container 100 of the refrigerated van, the apparatus 1 is connected, via the external connector 214, to a thermal charger that can take it to the right temperature and circulate the heat transfer fluid, whether liquid or gas, inside the heat exchanger 9. The heat transfer fluid brings the phase change material in the cavity 7 of the housing 5 of each thermal storage device 3 to a temperature that is lower than the characteristic solid-liquid transition temperature. During this phase of charging the phase change material, the doors of the container 100 may be open for loading/unloading of the goods to be transported. When the thermal charging has been completed and the phase change material has reached the predefined temperature that ensures a complete change of state of the liquid, the thermal charger is stopped and the goods may be transported and distributed, opening the doors of the container 100 when necessary. The thermal charger can include an AC or DC compressor, and may be stand-alone or be installed on the van and be capable, in relation to the predefined configuration, to perform the functions of thermal charging for the Class A and Class C versions, heating for Class A vehicles for use in particularly cold climates, rapid defrosting for Class C versions and lowering of the temperature of goods loaded at non-optimal or non-standard temperatures.
In an embodiment, it is possible to trigger defrosting of the apparatus 1 by circulating a heat transfer fluid through the passage conduit 17, the fluid working sufficiently quickly so as not to bring the temperature of the goods inside the container 100 above that specified in applicable standards. By circulating the heat transfer fluid through the passage conduit 17, the layer of ice formed on the wall of the apparatus is quickly melted. In particular, thanks to the high heat conductivity of aluminum and the high temperature of the heat transfer fluid, it is possible to quickly defrost the housing 5 by melting a very thin layer of the phase change material in direct contact with the aluminum walls of the housing. In other words, the high heat capacity of the phase change material, the high heat conductivity of aluminum and the high temperature of the heat transfer fluid all combine to complete defrosting so quickly that the temperature inside the container 100 as laid down by applicable standards is not exceeded. The heat transfer fluid may be a liquid or a gas under pressure.
If the external temperature is lower than the temperature laid down by the applicable standard for chilled goods, in particular by Class A of the ATP standard, the thermal charger may, in an embodiment, be used to heat the phase change material up to about 90° C., and the phase change material, using the sensible heat stored, can maintain the desired temperature inside the container 100 of the refrigerated van while the goods are being transported and distributed. In another embodiment, the thermal charger may be used to heat the phase change material up to about 60° C.
As stated above, the apparatus 1 can make it possible to control exchanges of heat with the internal space 112 of the container 100, where the goods are stored.
In particular, the wall 11 of the housing 5 facing the internal space 112 has a flat surface, while the wall 13 facing the end wall 102 of the container 100 is least partially finned, with a “heat exchange surface”/“surface taken up” ratio of from about 2:1 to about 6:1, according to an embodiment. Total heat exchange therefore depends also on the heat exchange coefficient related to the speed of the airflow, and therefore it may range from about 2 W/m²K, in the case of natural convection, up to about 25 W/m²K in the case of forced ventilation. Consequently, the ratio between the heat exchange capacities of the wall 11 with a substantially flat surface and the wall 13 with an at least partially finned surface may range from a ratio of about 1:2 to a ratio of about 1:100, according to an embodiment.
In one embodiment, the following advantages may be obtained:
1) the phase change material may be completely thermally charged without damaging any “chilled” goods due to excessive temporary and/or localized heating of the internal space 112 of the container 110;
2) use of the heat energy stored in the thermal storage device 3 is optimized;
3) the apparatus 1 may also be used in very cold climates, reversing the thermal gradients of operation of the apparatus 1.
Some aspects of the operation of the apparatus 1 are illustrated by the examples below.
In one example, a 7.5 tonne Class A refrigerated van is used to transport and distribute “chilled” goods. The surface area for heat exchange with the outside of the refrigerated container of the van is about 37 m², while the heat exchange coefficient thereof is about 0.45 W/m²K. The heat conductivity of the container thus stands at about 16.5 W/K.
Then suppose we use an apparatus 1 for storing refrigerated or frozen goods, according to the disclosure, with the following features:

- the wall 11 with a flat surface, facing the internal space of the refrigerated container, has a surface area of about 0.8 m², and a heat exchange coefficient of about 2 W/m²K.
- the wall 13 with an at least partially finned surface has a surface area of about 2.5 m², and a heat exchange coefficient which, with maximum ventilation, may reach about 25 W/m²K.

Based on these data, the wall 11 with a flat surface has a heat conductivity of about 1.6 W/K, while the heat conductivity of the wall 13 with an at least partially finned surface may reach about 62.5 W/K.
Thus, in the case of the storage of “chilled” goods, during the phase of cooling of the phase change material, i.e. when the ventilator 15 is inactive, it is possible to bring the phase change material to a temperature well below the about 1° C. required to store chilled goods, for example to a temperature of about −9° C., since the lower heat conductivity of the flat surface (about 1.6 W/K) with respect to the heat conductivity of the container (about 16.5 W/K) means that the container may not be excessively cooled, preventing damage to the “chilled” goods. Furthermore, and this goes both for the abovementioned Class A van for transporting “chilled” goods and for Class C vans for transporting “frozen” goods at temperatures of about −18° C., the fact that the heat conductivity of the wall 11 with a flat surface is about 1.6 W/K and that, by contrast, the heat conductivity of the wall 13 with an at least partially finned surface may range from very low values up to more than about 60 W/K, under forced ventilation at high speed and with fins with a high heat exchange surface area, means that the absorption of heat from the internal space 112 of the container is optimized. Thus, for example in the case of “frozen” goods, the temperature of the phase change material tends to remain around, for example, about −30° C., while the temperature specified by the applicable standard should be below about −18° C./about −20° C., and therefore the heat exchange may be adjusted according to the ambient temperature or the frequency of opening of the doors, with a consequent significant saving in energy with respect to constantly maintaining the temperature at about −30° C. The apparatus 1 may also be used for storing “chilled” goods, which thus should be kept at a temperature of at least about 1° C., in very cold countries where the temperature falls below about −10° C. and may even reach about −50° C.
In particular, the phase change material may be heated to a temperature of up to about 90° C., according to an embodiment. In the example of the abovementioned Class A van, the wall 11 with a flat surface can transmit up to about 142 W of power, in terms of heat, obtained by multiplying the heat conductivity value of about 1.6 W/K by the difference in temperature of about 89 K (obtained by subtracting, from the temperature of about 90° C. of the phase change material, the temperature of about 1° C. which it is desired to have inside the van container).
Based on the caloric power of about 142 W, the wall 11 with a flat surface, alone, is capable of maintaining the internal temperature at about 1° C. for external temperatures of up to about −8° C.
If the external temperature should fall further, to below about −8° C., it is possible to trigger the ventilator 15, and thus heat the internal space 112 of the container, to keep it at the desired temperature of about 1° C.
Furthermore, considering the high heat conductivity of the wall 13 with an at least partially finned surface (up to about 62.5 W/K), a temperature of about 15° C. for the phase change material would be sufficient to keep the temperature inside the refrigerated container at about 1° C., even for external temperatures of about −50° C.
The phase change material, according to an embodiment of the present disclosure, may also have the following features:

- it is compatible with aluminum;
- it has a high heat of fusion and a high sensible heat;
- it may be used for storing heat both in the transition phase and in the liquid phase;
- its phase transition temperature is such that it may be used as a thermal buffer that absorbs changes in temperature caused by the heat exchanger 9, to prevent damage to the goods inside the container 100.

Regarding the use of aluminum as the material for making both the housing 5 of the thermal storage device 3 and the heat exchanger 9, it may offer better thermal performance and better workability, in terms of being extruded into various shapes, and in particular fins for the wall 13 with the most suitable shape and size.
In particular, the apparatus 1 for the storage, transport and distribution of refrigerated or frozen goods can have a high energy efficiency due to the interaction between the exchange of heat obtained at a rate of over about 90% on the side of the heat exchanger 9 facing the end wall 102 of the container 100, which optimizes the use of the heat energy stored according to the thermal charges, the fact that it is possible to regulate the internal temperature using the ventilator 15, which can create an airflow between the heat exchanger 9 and the end wall 102 with speeds varying from about 0 to about 12 meters per second, means that an optimal internal temperature may be maintained irrespective of the point at which the phase change material changes state, without creating unnecessarily high thermal flows between the external environment and the insulated thermal container, allowing the use of cooling fluids at a temperature as close as possible to the point of change of state, and therefore optimizing the COP of the compressors of the thermal charging unit.
Furthermore, the temperature at which the phase change material used for chilled goods changes state may be such that the formation of frost on the thermal storage device during the charging phase melts during transport and therefore periodic defrosting may not be required.
The apparatus for the storage of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated transport vehicles, cold rooms and the like, according to the present disclosure, can achieve the aim and objectives set as it enables the transport of perishable “chilled” or “frozen” goods in a manner that is economically competitive, reliable, energy efficient and environmentally friendly.
In particular, an embodiment of the above apparatus can have the following advantages:
a) the possibility of controlling and varying the exchange of heat makes it possible to modulate the operation of the apparatus according to the various thermal loads due to the different external conditions or the different conditions of use such as the frequency and duration of opening of the doors, the temperature and the metabolic heat of the goods stored in the refrigerated container, the result being a considerable reduction in thermal, and therefore electrical, consumption and a reduction in tare for the same level of thermal autonomy;
b) the fact that it can be used in both warm and extremely cold climates, for the storage of both “chilled” goods and “frozen” goods. Indeed, in particularly cold climates, where there is a risk of “chilled” goods being damaged owing to excessively low temperatures, it possible to reverse the heating cycle, exploiting the sensible heat of the phase change material to offset any excessive drops in temperature inside the refrigerated container;
c) on average it has a lifetime that is longer than the lifetime of the refrigerated van in which it is installed;
d) it is easily and quickly installed in a refrigerated van, without the need for specialized personnel in refrigeration plants with the necessary refrigeration equipment such as vacuum pumps, metering systems for charging with gas, gastight welding equipment, etc. thanks to the one-piece configuration that allows full preassembly of the system, including charging with gas and the provision of the refrigeration connections by means of quick-connects and electrical connections by means of connectors;
e) it does not require complex, laborious and heat-conducting securing fixtures embedded in the insulating structure of the vehicle, as the one-piece structure of the disclosure and the fact that it is installed next to the end wall mean that the weight is taken up by the floor, so that all that is needed on the wall is a support member that is compatible with the structural features of usual insulating structures; thus, unlike in the case of eutectic plates for example, which are attached to the ceiling of the refrigerated container, the center of gravity of the vehicle is not raised, making the vehicle more stable and safe.
The above-described apparatus for the storage of refrigerated or frozen goods, in particular for refrigerated van containers and the like, may be modified in many ways without departing from the scope of the disclosure.
Furthermore, all the details thereof may be substituted by other technically equivalent features.
In practice, the materials used, as long as they are compatible with the specific use in question, and the dimensions and shapes selected, may be as required in each case.

ASPECTS

It is noted that any of aspects 1-11 below can be combined with each other in any combination and combined with any of aspects 12, 13, 14-28, 29-32, or 33-35. Any of aspects 12, 13, 14-28, 29-32, or 33-35 can be combined with each other in any combination.
Aspect 1. An apparatus for the storage, transport and distribution of refrigerated or frozen goods, in particular for thermally insulated containers of refrigerated vehicles, cold rooms and the like, comprising:
one or more thermal storage devices, each comprising:

- a housing defining a cavity for holding a phase change material, the cavity containing a heat exchanger that may be supplied with a heat transfer fluid, wherein the housing has a first wall with a substantially flat surface and a second wall, opposite the first wall, with a surface that is at least partially finned, a ventilator being associated with the one or more thermal storage devices.
  Aspect 2. The apparatus according to aspect 1, wherein the housing includes a conduit for the passage of a heat transfer fluid associated with at least one of the first wall and the second wall.
  Aspect 3. The apparatus according to any of aspects 1-2, wherein the internal surface of the conduit for the passage of the heat transfer fluid includes a plurality of internal fins to promote the exchange of heat between the heating liquid and the heat-conducting material of which the passage conduit is made.
  Aspect 4. The apparatus according to any of aspects 1-3, wherein the phase change material includes one of:

hydrogen peroxide in concentrations of between about 0% and about 35%; and
n-decane.
Aspect 5. The apparatus according to any of aspects 1-4, wherein the housing is made of aluminum.
Aspect 6. The apparatus according to any of aspects 1-5, wherein the phase change material may be cooled so as to maintain the temperature of the internal space of a container of a refrigerated vehicle or the like below the ambient temperature outside the container, by the heat of fusion of the phase change material, or it may be heated, to maintain the temperature of the internal space of the container above the ambient temperature outside the container, by the sensible heat of the phase change material.
Aspect 7. The according to any of aspects 1-6, further comprising a temperature sensor for measuring the temperature inside the container, and the power of the ventilator may be controlled as a function of the temperature inside the container.
Aspect 8. The apparatus according to any of aspects 1-7, wherein the ventilator is capable of generating an airflow with speeds varying in the range between about 0 and about 12 meters per second.
Aspect 9. The apparatus according to any of aspects 1-8, wherein the heat exchanger has a U-shaped tubular profile, the internal surface of which, which is in contact with the heat transfer fluid, includes a plurality of fins.
Aspect 10. The apparatus according to any of aspects 1-9, wherein the housing of each thermal storage device includes a relief valve for letting off excess pressure that builds up inside the housing.
Aspect 11. The apparatus according to any of aspects 1-10, wherein the housing of each thermal storage device includes, at the top, a closable hole for pouring in and refilling the phase change material and, at the bottom, a collector for draining off the phase change material.
Aspect 12. A container of a refrigerated vehicle or the like, comprising:
an apparatus for the storage, transport and distribution of refrigerated or frozen goods as claimed in one or more of the preceding claims, wherein the apparatus is positioned adjacent to the end wall of the container, but not attached to the end wall, and raised off the floor of the container, the ventilator being arranged at the top of the apparatus, near the ceiling of the container, the second wall with an at least partially finned surface of the housing facing the end wall, the ventilator being capable of generating an airflow, that passes between the floor and the apparatus, enters the gap between the apparatus and the end wall, skimming the second wall, and passes through the ventilator, before being dispersed in the container.
Aspect 13. A container of a refrigerated vehicle or the like, according to aspect 8, wherein the first wall of the apparatus with a substantially flat surface can exchange heat by natural convection, the second wall, with an at least partially finned surface, making, with the end wall of the container, a channel for the forced, regulated and controlled passage of an airflow generated by the ventilator.
Aspect 14. An apparatus for a refrigerated vehicle, comprising:
one or more thermal storage device, including:

- a housing, including a substantially flat wall portion and a heat transfer enhanced wall portion,
- a cavity defined by an interior of the housing,
- a phase change material contained within the cavity, and
- a heat exchanger configured to receive a heat transfer fluid; and

a ventilator in communication with the one or more thermal storage device.
Aspect 15. The apparatus according to aspect 14, wherein the housing includes:
a conduit for passage of a second heat transfer fluid, wherein the conduit is in communication with a wall of the housing.
Aspect 16. The apparatus according to aspect 15, wherein an internal surface of the conduit includes a plurality of internal fins for exchanging heat between the second heat transfer fluid and the conduit.
Aspect 17. The apparatus according to any of aspects 14-16, wherein the phase change material has a solid-liquid transition temperature between about 0° C. and about −32° C.
Aspect 18. The apparatus according to any of aspects 14-17, wherein the housing is made of aluminum and the phase change material is aluminum compatible.
Aspect 19. The apparatus according to any of aspects 14-18, wherein the phase change material is configured to maintain an internal space of the refrigerated vehicle at a temperature that is below an ambient temperature.
Aspect 20. The apparatus according to any of aspects 14-19, wherein the phase change material is configured to maintain an internal space of the refrigerated vehicle at a temperature that is above an ambient temperature.
Aspect 21. The apparatus according to any of aspects 14-20, further comprising:
a temperature sensor for determining a temperature of an internal space of the refrigerated vehicle.
Aspect 22. The apparatus according to any of aspects 14-21, wherein one or more settings of the ventilator are controlled as a function of the temperature of the internal space.
Aspect 23. The apparatus according to any of aspects 14-22, wherein the heat exchanger has a U-shaped tubular profile.
Aspect 24. The apparatus according to aspect 23, wherein an inner surface of the U-shaped tubular profile includes a plurality of fins.
Aspect 25. The apparatus according to any of aspects 14-24, wherein the housing includes a relief valve for releasing pressure from the cavity of the housing.
Aspect 26. The apparatus according to any of aspects 14-25, wherein the housing includes at least one of:
a closable hole for filling the phase change material into the housing, and
a collector for draining the phase change material.
Aspect 27. The apparatus according to any of aspects 14-26, wherein the ventilator is configured to circulate an airflow in an internal space of the refrigerated container, thereby transferring heat between the thermal storage device and the internal space by convection.
Aspect 28. The apparatus according to any of aspects 14-27, wherein the heat transfer enhanced wall portion includes one or more fins.
Aspect 29. A thermal storage device for use in a refrigerated vehicle, comprising:
a housing that includes a heat transfer enhanced wall portion and a substantially flat wall portion;
a cavity defined by an interior of the housing;
a phase change material contained within the cavity; and
a heat exchanger configured to receive a heat transfer fluid.
Aspect 30. The thermal storage device according to aspect 29, wherein the heat transfer enhanced wall portion includes one or more fins.
Aspect 31. The thermal storage device according to aspect 29, wherein the phase change material has a solid-liquid transition temperature between about 0° C. and about −32° C.
Aspect 32. The thermal storage device according to any of aspects 29-31, wherein the housing is made of aluminum and the phase change material is aluminum compatible.
Aspect 33. A method of controlling refrigeration in a refrigerated vehicle, comprising:
determining a temperature in an internal space of the refrigerated vehicle;
facilitating heat exchange within the internal space with one or more thermal storage devices and a ventilator in communication with the one or more thermal storage devices, the thermal storage devices including a housing, including a substantially flat wall portion and a heat transfer enhanced wall portion, a cavity defined by an interior of the housing, a phase change material contained within the cavity, and a heat exchanger configured to receive a heat transfer fluid; and
controlling the ventilator to provide an airflow configured to convectively transfer heat from the one or more thermal storage devices and to provide the airflow to the internal space of the refrigerated vehicle.
Aspect 34. The method according to aspect 32, wherein the determining the temperature in the internal space of the refrigerated vehicle includes monitoring one or more temperature sensors.
Aspect 35. The method according to any of aspects 32-33, wherein the controlling the ventilator to provide an airflow configured to convectively transfer heat from the one or more thermal storage devices and to provide the airflow to the internal space of the refrigerated vehicle includes modifying a speed of the airflow.
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, indicate 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. The word “embodiment” as used within this specification may, but does not necessarily, refer to the same embodiment. This specification and the embodiments described are exemplary only. Other and further embodiments may be devised without departing from the basic scope thereof, with the true scope and spirit of the disclosure being indicated by the claims that follow.

Claims

What is claimed is:

1. An apparatus for a refrigerated vehicle, comprising:

one or more thermal storage devices, including:

a housing, including a substantially flat wall portion and a heat transfer enhanced wall portion,

a cavity defined by an interior of the housing,

a phase change material contained within the cavity, and

a heat exchanger configured to receive a heat transfer fluid; and

a ventilator in communication with the one or more thermal storage devices.

2. The apparatus according to claim 1, wherein the heat transfer enhanced wall portion includes one or more fins.

3. The apparatus according to claim 1, wherein the housing includes:

a conduit for passage of a second heat transfer fluid, wherein the conduit is in communication with a wall of the housing.

4. The apparatus according to claim 3, wherein an internal surface of the conduit includes a plurality of internal fins for exchanging heat between the second heat transfer fluid and the conduit.

5. The apparatus according to claim 1, wherein the phase change material has a solid-liquid transition temperature between about 0° C. and about −32° C.

6. The apparatus according to claim 1, wherein the housing is made of aluminum and the phase change material is aluminum compatible.

7. The apparatus according to claim 1, wherein the phase change material is configured to maintain an internal space of the refrigerated vehicle at a temperature that is below an ambient temperature.

8. The apparatus according to claim 1, wherein the phase change material is configured to maintain an internal space of the refrigerated vehicle at a temperature that is above an ambient temperature.

9. The apparatus according to claim 1, further comprising:

a temperature sensor for determining a temperature of an internal space of the refrigerated vehicle.

10. The apparatus according to claim 9, wherein one or more settings of the ventilator are controlled as a function of the temperature of the internal space.

11. The apparatus according to claim 1, wherein the heat exchanger has a U-shaped tubular profile.

12. The apparatus according to claim 11, wherein an inner surface of the U-shaped tubular profile includes a plurality of fins.

13. The apparatus according to claim 1, wherein the housing includes a relief valve for releasing pressure from the cavity of the housing.

14. The apparatus according to claim 1, wherein the housing includes at least one of:

a closable hole for filling the phase change material into the housing, and

a collector for draining the phase change material.

15. The apparatus according to claim 1, wherein the ventilator is configured to circulate an airflow in an internal space of the refrigerated container, thereby transferring heat between the thermal storage device and the internal space by convection.

16. A thermal storage device for use in a refrigerated vehicle, comprising:

a housing that includes a heat transfer enhanced wall portion and a substantially flat wall portion;

a cavity defined by an interior of the housing;

a phase change material contained within the cavity; and

a heat exchanger configured to receive a heat transfer fluid.

17. The thermal storage device according to claim 16, wherein the phase change material has a solid-liquid transition temperature between about 0° C. and about −32° C.

18. The thermal storage device according to claim 16, wherein the housing is made of aluminum and the phase change material is aluminum compatible.

19. A method of controlling refrigeration in a refrigerated vehicle, comprising:

determining a temperature in an internal space of the refrigerated vehicle;

facilitating heat exchange within the internal space with one or more thermal storage devices and a ventilator in communication with the one or more thermal storage devices, the thermal storage devices including a housing, including a substantially flat wall portion and a heat transfer enhanced wall portion, a cavity defined by an interior of the housing, a phase change material contained within the cavity, and a heat exchanger configured to receive a heat transfer fluid; and

controlling the ventilator to provide an airflow configured to convectively transfer heat from the one or more thermal storage devices and to provide the airflow to the internal space of the refrigerated vehicle.

20. The method according to claim 19, wherein the determining the temperature in the internal space of the refrigerated vehicle includes monitoring one or more temperature sensors.

21. The method according to claim 19, wherein the controlling the ventilator to provide an airflow configured to convectively transfer heat from the one or more thermal storage devices and to provide the airflow to the internal space of the refrigerated vehicle includes modifying a speed of the airflow.