WO2024023247A1

WO2024023247A1 - Temperature-controlled container and method for the transport of perishable goods, in particular for land and/or maritime transport

Info

Publication number: WO2024023247A1
Application number: PCT/EP2023/070891
Authority: WO
Inventors: Alberto Ghiraldi
Original assignee: Swiss Passive Technologies Gmbh
Priority date: 2022-07-27
Filing date: 2023-07-27
Publication date: 2024-02-01
Also published as: CH719932A2

Abstract

A temperature-controlled container (1) for the transport of perishable goods, which comprises: - a monolithic box-shaped body (20) that is made of composite material comprising an inner core of an expanded insulating material, covered by an external layer; and - a cooling thermal storage unit (30, 40, 50) that is coupled to an inner wall (24) of said box-shaped body (20) and connected in fluid communication to an inlet port (91) for the inlet of a refrigerant fluid, and a suction port (92) for the extraction of said refrigerant fluid; wherein said cooling thermal storage unit (30, 40 50) comprises an outer casing (31, 41, 51) which comprises a thermal storage material consisting of a plurality of different thermal storage liquids having different melting points, in which a heat exchanger (52) is embedded which comprises at least one heat exchange duct (33) adapted to be passed through by the refrigerant fluid that is in transit between said inlet port (91) and said suction port (92).

Description

TEMPERATURE-CONTROLLED CONTAINER AND METHOD FOR THE TRANSPORT OF PERISHABLE GOODS, IN PARTICULAR FOR LAND AND/OR MARITIME TRANSPORT

Technical field

The present invention relates to a temperature-controlled container ("container" or "load unit") for the transport of perishable goods (such as food or medicines), in particular, a container with volumes between 100 liters and 100 m³, even more particularly a container or swap body for both truck and rail land transport suitable for being fixed integrally on a vehicle, for example on a trailer fifth wheel or flatbed of a truck or a railway wagon, for example by means of twist locks.

State of the art

As known, containers are used for loading goods of various types onto means of transport. The use of a container of this type makes it possible to load large quantities of goods with a single unit and also to load different products at different temperatures on the same vehicle, optimizing the time, means and personnel used for loading and unloading.

Containers and other refrigerated enclosures are normally used for the transport of goods that need to be kept within a certain temperature range in order not to perish, such as medicines and food.

In the prior art, the solutions used to make containers and other refrigerated enclosures can be grouped into three categories: active solutions, semi-passive solutions and passive solutions.

In active solutions, the container is provided with a refrigeration apparatus which must be continuously powered by an electric network or by batteries or by a diesel current generator for powering the refrigeration unit.

In semi-passive solutions, the container is kept refrigerated by dry ice which is loaded in large quantities before each travel and stored inside a special compartment in the container itself, which must be equipped with fans, powered by batteries, for temperature control.

In passive solutions, usually, the refrigerated container contains, inside or applied to the walls, a thermal storage material, such as a phase-change material or PCM (Phase-Change Material), and the container itself must be stored in a cold room for a period of time sufficient to freeze the thermal storage material (usually at least 24 hours) before each travel. Alternatively, the thermal storage material can be contained, rather than in the walls, in removable thermal packs which are frozen separately in a cold room and then installed along the walls of the refrigerated container.

Summary of the invention

Active solutions of the known type have the drawback that the operation of the refrigerated container depends on the availability of an electric network or its autonomy is limited by the batteries or the diesel tank. The batteries have the problems of insufficient power to power refrigeration units for periods exceeding 24 hours and of the rapid decay of the capacity with low temperatures and the diesel fuel has the problem of freezing. Furthermore, the presence of a dedicated refrigeration apparatus makes these containers complex and expensive to manufacture, maintain and certify. However, active systems have the advantage of being able to maintain different temperatures inside the containers.

Semi-passive solutions of the known type have the disadvantage of requiring a considerable logistical effort for the loading and mobilization of the dry ice, with also the related, known, safety problems and furthermore they do not cover the operation for the transport of fresh food products with low ambient temperatures.

Passive solutions have the disadvantage of requiring the use and availability of large cold rooms, as well as requiring a long preparatory time for freezing the thermal material and also a considerable logistical effort and a significant use of manpower for the mobilization of the refrigerated container into and from the cold room (in the case of thermal storage material integrated into the walls) or for the loading and installation of the thermal packs.

Furthermore, disadvantageously, this type of procedure for freezing the thermal storage material in cold rooms is very expensive from an energy point of view.

Passive solutions do not cover operation in the presence of low ambient temperatures which are particularly critical for the transport of fresh food products and medicines. These solutions have the disadvantage of being able to maintain a single temperature depending on the state transition point of the PCM that is used and do not allow to operate at different temperatures.

The main task of the present invention is to provide a temperature- controlled container capable of solving the problems and overcoming the limitations of the prior art as set out above.

Within the framework of this task, an object of the present invention is to provide a temperature-controlled container which in use does not involve the logistical efforts or the safety problems described above, typical of known passive and semi-passive solutions.

Another object of the invention is to provide a temperature- controlled container which is capable of maintaining the internal temperature for periods of up to over 30 days at values of 0/+4°C for fresh food products complying with class A of the ATP regulation and +2/+8°C or +15/+25°C for pharmaceutical products or at temperatures < -18°C for frozen products complying with class C of the ATP regulation.

Another object of the invention consists in providing a temperature- controlled container which is more efficient from an energy point of view. A further object of the invention consists in providing a temperature- controlled container which has a better thermal autonomy, possibly up to 30 days both in the refrigeration phase in hot environments and in the heating phase in the presence of low temperatures down to -50°C.

Another object of the invention consists in providing a temperature- controlled container that can operate independently of the availability of an electric network during the travel.

Not least object of the invention is to provide a temperature- controlled container which is easy to manufacture and use as well as economically competitive.

The above task, as well as the mentioned objects and others which will become apparent hereinafter, are achieved by a temperature- controlled container according to claim 1 .

This task and these and other objects are also achieved by a system according to claim 13 and also by a method according to claim 14.

Brief description of the drawings

Further features and advantages will become clearer from the description of some preferred, but not exclusive, embodiments of a temperature-controlled container, illustrated for indicative and nonlimiting purposes with the aid of the accompanying drawings in which:

Figure 1 is a perspective view of a possible embodiment of a temperature-controlled container, according to the present invention, in which the walls of the container have been made transparent for greater clarity;

Figure 2 is a perspective view of the thermal storage unit of the container of Figure 1 ;

Figure 3 corresponds to Figure 2, where part of the outer casing of the thermal storage unit has been removed to show its content; Figure 4 is a schematic representation of the operation of a temperature-controlled container together with a thermal charge apparatus, according to the present invention;

Figures 5, 6, 7 and 8 show two thermal storage units arranged both on the wall and on the ceiling;

Figure 9 is a sectional view of a possible embodiment of a temperature-controlled container according to the present invention;

Figure 10 is a perspective view, from the outside, of a further possible embodiment of a temperature-controlled container according to the present invention;

Figure 11 is a section of the container of Figure 10.

Detailed description of embodiments of the invention

With reference to the cited Figures, the temperature-controlled container, indicated globally with the reference number 1 , 1 ', 1" in the preferred embodiments, is included in a means of transport and distribution for road and/or rail and/or maritime use. In alternative embodiments, the container 1 can have a volume of 100 liters up to a volume of 100 m³ typical of a 13.60 m swap body or a 45' HC container with the possibility of products with intermediate dimensions such as to cover the whole range of means of truck, rail and maritime distribution and transport.

The container is at a controlled temperature in the sense that it is advantageously able to maintain products in the temperature range suitable for both food products that respond to class A of ATP regulation (0/+4°C), and to pharmaceutical products (+2/+8°C), other products that require temperatures +9/+12°C or +15/+25°C, both in summer, with environmental conditions up to +50°C or at temperature <-18°C for frozen products compliant with class C of the ATP regulation.

According to the present invention, the temperature-controlled container 1 comprises a monolithic box-shaped body 20 which is made of composite material comprising an inner core of polymeric material (preferably of expanded insulating material such as expanded polyurethane) covered by an external layer preferably of resin (or other suitable material), and even more preferably constituted by an inner core of expanded insulating material such as expanded polyurethane, an internal and external coating preferably of special high-strength resin or other equivalent material, with thicknesses between 0.5 and 6 mm, with, where required, incorporated reinforcements by impregnation of glass fiber and/or Kevlar and/or carbon fiber located in the points of particular criticality both in terms of structure and impact resistance and high-strength steel components located in the points where the container is attached to the floor of the vehicles on which it will be fixed. This makes it possible to obtain appropriate structural and impact resistance features in points that are particularly stressed. In the injection phase, steel plates are also inserted in the points where the container is attached to the frame of the means of transport, which allow to obtain a completely integrated container and to avoid the use of external frames.

The temperature-controlled container 1 then comprises one or more thermal storage units for cooling 50, 30, 40 (also referred to as cooling thermal storage units) coupled to a respective internal wall 23 (where "wall" means both any side wall and the ceiling) of the box-shaped body 20.

Advantageously, the thermal storage units contain PCMs with different melting points according to the internal temperatures to be obtained. These different PCMs can also be contained in the same thermal accumulator if they are immiscible with each other, have different specific weights and different expansions following the change of state. This allows the desired PCM to be frozen during the charge phase and thus obtain the desired internal temperatures according to the thermal charge procedure. For example, <-18°C or 0/+4°C etc.

In practice, the container can be equipped with several thermal storage units which can either contain thermal storage liquids with different melting points or contain different thermal storage liquids in the same thermal storage unit, which cannot be mixed with each other, so as to maintain different temperatures inside the container depending on the charge mode.

The expression, referred to each thermal storage unit, "coupled to the internal wall of the box-shaped body" indicates that a wall of the outer casing of the thermal storage unit is fixed to the internal wall of the box-shaped body, i.e. , it leans adherently against this internal wall or integrated into it.

A second thermal storage unit for heating (also referred to heating thermal storage unit), suitably insulated, can be installed in the preferred position both inside and outside if the climatic conditions require it and typically in all cases in which the ambient temperature is lower than the storage temperature of the products to be transported.

In the preferred embodiment, the cooling thermal storage unit 50 is fixed to the wall 23 by means of fixing brackets 58.

Advantageously, the monolithic box-shaped body 20 is made of expanded polyurethane and is made in a single injection (in a single mold), thus allowing manufacturing it in a single phase rather than with multiple steps consisting in the manufacturing of the individual wall panels, their assembly, welding and restoration of the insulating structure. In this way the box-shaped body 20, formed by a single monolithic piece of polyurethane, has no joints and has a better thermal insulation coefficient than traditional containers made of assembled single wall-panels (a K coefficient is found that is approximately 10-30% lower than the aforementioned traditional containers).

The monolithic box-shaped body 20 can be coated with special resins so as to form a composite and/or with an external shell and/or with panels and/or with other coating or reinforcing elements of a known type.

In the preferred embodiments for cooling only, there is only one thermal storage unit 50, 30, 40 preferably coupled to a vertical side wall of the box-shaped body 20. In other embodiments, the thermal storage unit 50 is coupled to an upper horizontal wall (i.e., to the ceiling) of the box-shaped body 20 or to the side walls and ceiling with the consequent installation of three thermal storage units in which PCMs with different state transition points can be inserted so as to allow the maintenance of different internal temperatures according to different thermal charge procedures. In general, according to the present invention, the thermal storage unit 30, 40 50 can be coupled to any wall of the box-shaped body 20 according to the thermal autonomy requirements.

Embodiments are envisaged in which there are more than two thermal storage units 30, 40, 50, 250 of which at least one for cooling and, if required by the environmental conditions, at least one for heating 250 (the heating storage unit 250 can take the place, in the embodiments illustrated in the Figures, of any of the units indicated with reference numbers 50, 30 and 40).

According to the present invention, the thermal storage unit for cooling 50, 30, 40 is connected in fluid communication with an inlet port 91 for the inlet of a refrigerant fluid and with an outlet port 92 for the suction of the refrigerant fluid. The refrigerant fluid will be referred to also as refrigerant or cooling liquid. These expressions will be used interchangeably.

According to the present invention, the thermal storage unit 50, 30, 40 comprises an outer casing 31 , 41 , 51 (preferably made of aluminum) which contains a thermal storage material (i.e., which defines internally a hermetic containment cavity in which the thermal storage material is contained) in which a heat exchanger 52 (evaporator) is embedded.

The thermal storage material for cooling is preferably a phase change material (PCM).

The phase change material can consist of a mixture of different phase change materials. An advantageous feature of the present invention is to be able to maintain four different internal temperature ranges for the period of thermal autonomy defined as a function of the thermal charge mode by exploiting the features of one or more PCMs combined with each other and suitably integrated into the structure and/or even mixed with each other thus obtaining state transition points such as to respond to all the temperatures required by the regulation for the transport of food and pharmaceutical products.

Conveniently, the cooling thermal storage unit 50, 30, 40 comprises a valve for venting and loading of the thermal storage material 81 which allows the loading of this material inside the outer casing 51 , 41 , 31.

Conveniently, the thermal storage unit 50 comprises an expansion valve 85 connected to the heat exchanger 52 (evaporator). The expansion valve 52 is thermostatic and regulates the flow of liquid to the evaporator, at a volume equal to the evaporation of the liquid in the evaporator itself, maintaining a certain overheating value at the evaporator outlet (suction line) which ensures that all the cooling liquid vaporizes in the evaporator and that only the cooling liquid in gaseous form returns to the compressor.

The thermal storage material for heating referred to is preferably a high-boiling material which allows using sensible heat with DT versus internal temperature typically above 100°C.

Optionally, there is also a heating thermal storage unit 250.

Conveniently, the heating thermal storage unit 250 comprises a valve for venting and loading the thermal storage material 281 which allows the loading of this material inside the outer casing 251 and the controlled variation of the volume due to the variation of the temperature.

Conveniently, the heating thermal storage unit includes internal resistances for heating up to the required set point of the high-boiling liquid, a thermostat and external insulation to avoid overheating the compartment for the transport of products at a controlled temperature.

The outer casing 51 , 41 , 31 can have a parallelepiped shape, or a suitably contoured shape, and defines a parallelepiped cavity inside it. According to preferred embodiments of the present invention, the outer casing 51 , 41 , 31 has flat surfaces.

Even more preferably, the outer casing 51 , 41 , 31 of the cooling thermal storage unit is made of aluminum having a thickness of between 1 and 4 mm, while that of the heating thermal storage unit 250 which will be described below is preferably made of stainless steel.

Preferably, the container body 20 consists of an expanded polyurethane shell coated with special resins (or other material) applied directly on the polyurethane shell or directly on the mold before foaming ("spray in mold") thus allowing to obtain with a single manufacturing phase a monolithic product with high impact resistance, low thermal conductance, greatly reduced tare weight compared to conventional construction technologies and reduced manufacturing times since the assembly phases between the walls have been eliminated. The internal volume is from 100 to 100,000 liters in embodiments of the type of a land transport container in which there are one to three thermal storage units 30, 40, 50 for cooling and, if required by ambient climatic conditions, one or two thermal storage units for heating 250.

In the preferred embodiments, the thermal storage unit for cooling comprises profiled structural elements 55 with preferably T-shaped section preferably having dimensions between 10x10x2 and 50x50x5 mm, which are coupled (by welding) to the outer casing 51 , 31 , 41 so as to reinforce it mechanically and optimize the heat exchange surface suitable for maintaining a temperature differential between the surface of the thermal accumulator and the internal air such as to guarantee the maintenance of internal temperature within the range required by regulation. These profiled structural elements 55 also serve as spacer and support elements for an interface shield 57, 47, 37 (practically a panel) fixed to the outer casing 51 , 41 , 31 and facing the inside of the container 1 . The interface thermal shield 57 is positioned towards the inside of the container 1 so as to at least partially cover the thermal storage unit 50 and thus be able to vary the internal temperature with respect to the (fixed) melting point of the thermal storage liquid, this shield is equipped with shutters that can be adjusted according to the climatic conditions and the product to be transported, thus obtaining a variable temperature within the ranges envisaged by the regulation despite the fixed melting point. Alternatively, the same result can be obtained by stamping (deep drawing) the sheet metal or by using "comb" extrusions suitably welded together so as to form a container of the desired dimensions. The thermal storage unit will therefore have a finned surface positioned preferably, but not necessarily, vertically towards the load compartment and a flat surface towards the wall of the container. If, in case of a horizontal arrangement of the fins, stiffening is necessary to avoid deformations due to hydrostatic pressure, a structural connection will be created between the finned wall facing the load compartment and the flat one leaning against the insulated wall.

According to an optimal solution, the thermal storage unit 30, 40, 50 can be provided with a thermal shield 37, 47, 57 preferably made of a HDPE sheet covering most or all of the visible surface of this thermal storage unit 30, 40, 50. This thermal shield 57 has the function of increasing the AT between the temperature of the surface of the thermal accumulators and the internal air and so as to be able to use the same container with the same PCM for the transport of products at different temperatures including food products that require a temperature between 0/+4°C, both other food products, such as bananas and chocolate that require around 12°C, and for pharmaceutical products that require a temperature between +2/+8°C while the surface of the thermal storage unit is typically at 0/+1 °C.

According to an optional advantageous feature, the thermal storage unit 50 is equipped with a thermal shield with a shutter to be able to manually adjust, before shipping, the flow of natural convection and/or ventilation according to winter or summer use and the temperatures to be obtained inside.

The heat exchanger 52 comprises a heat exchange duct (and more precisely an evaporator) 33, adapted to be crossed by the refrigerant fluid in transit between the inlet port 91 and the suction port 92, so that by passing through the heat exchange duct 33, the cooling fluid cools the thermal storage material, for example causing it to change phase (solidifying it).

Preferably, the cooling thermal storage units 30, 40, 50 each contain one or more thermal evaporators having the following features: a) made with dimensions compatible with the construction capabilities of existing machinery and, therefore, possibly divided into a plurality of evaporating sub-modules of adequate dimensions; b) that said evaporating sub-modules inserted in each thermal storage unit 30, 40, 50 are preferably connected to each other in parallel; c) that the circuits for the distribution of the refrigerant fluid in these evaporating sub-modules are in turn connected to each other in parallel so as to obtain uniform distribution of the temperature along the entire thermal storage unit 50 itself; d) that the supply of the refrigerant fluid to said evaporating submodules is achieved through expansion valves which can supply one or more evaporating sub-modules in relation to the dimensions of the sub-modules themselves; e) that if the construction requirements involve a plurality of expansion valves each supplying one or more sub-modules of the thermal storage unit 50, the same will be calibrated individually so as to obtain a uniform temperature among all the sub-modules of the same thermal storage unit 50 and, if there are several thermal storage units 30, 40, 50, the uniformity of the temperature among all the thermal storage units 30, 40, 50.

Preferably, the heat exchanger 52 also comprises a series of fins or blades 54 to facilitate the heat exchange between the refrigerant fluid and the thermal storage material. Conveniently, the fins or blades have an arrangement and construction such as to obtain an exchange surface between the evaporator and the thermal storage liquid of between 3 and 20 litres/m²

These fins or blades 54 have the dual function of absorbing heat during the thermal charge phase so as to obtain the rapid and uniform change of state of the thermal storage liquid and, when, subsequently, in use, the uniform absorption of the heat entering the walls by the change-of-state product.

According to an optimal solution, in the embodiment of Figures 1 -3, the heat exchange duct 33 comprises a series of side-by-side pipes arranged along parallel planes, each of which forms a coil arranged along a respective plane, in which each coil comprises mutually parallel linear portions connected in parallel by a delivery manifold and an intake manifold and by curved connection portions (the curved connection sections are visible in Figure 3).

Advantageously, the fins 54 are each provided with a series of through holes through which the linear portions of the coils of the evaporating circuit pass, these fins being arranged parallel to each other and perpendicular to the planes on which the coils of the evaporating circuit extend.

In some alternative embodiments, the thermal storage unit 50 comprises a heat exchanger comprising a plurality of heat exchange ducts hydraulically positioned in parallel, which pass through the through holes of the fins 54.

The heat exchanger 52 (evaporator) is preferably positioned in contact with a wall of the outer casing 51 , 41 , 31 and more precisely with the wall facing the inside of the container.

The thermal storage material can be a phase change material, preferably in liquid form when at room temperature which solidifies following the cooling caused by the heat exchange with the refrigerant fluid.

Preferably, each thermal storage unit 30, 40, 50 for cooling which uses a state change liquid comprises within it a compressible layer for absorption of the change in volume, interposed between at least part of the outer casing 51 , 41 , 31 and the thermal storage material (i.e. , it substantially covers one or more inner walls of the outer casing 51 , or one or more parts of such one or more walls). This compressible layer for absorbing the volume change is configured to absorb an increase in volume of the thermal storage material due to its phase change following cooling: in practice, when the thermal storage material solidifies and increases in volume, the compressible layer for absorbing the volume change is able to compress, compensating for this increase in volume and cushioning the consequent forces so as to avoid damage to the outer casing 51 , 31 , 41 and deformations thereof.

More in detail, the compressible volume change absorption layer comprises a plurality of cells adapted to be compressed and is preferably composed of high-density expanded polyethylene (HDPE). Even more preferably, the compressible volume change absorption layer has a thickness to volume ratio of between 8% and 30% of the volume of phase change material.

In preferred embodiments, the compressible volume change absorption layer surrounds one face of the heat exchanger 52, 42, 32 by covering one of the inner walls of the outer casing 51 , 41 , 31.

Optionally, the container 1 also comprises a heating thermal storage unit 250 comprising one or more electric heating resistances 249 immersed in a thermal storage liquid preferably having high- boiling features. Conveniently, this thermal storage liquid has high- boiling features for the use of sensible heat with temperatures up to 350°C; alternatively, inert products having a high sensible heat can also be used. The heating thermal storage unit 250 preferably has external insulation to limit the direct exchange between said thermal storage unit and the internal environment of the container 1 to the sole operation of the fans which are for example activated by an electronic temperature control system powered by batteries housed in the container or by photovoltaic panels installed on the roof of the vehicle.

The thermal storage unit for heating 250 is strongly insulated so as not to affect the internal temperature of the container except when required by the temperature sensor which activates a ventilation or liquid circulation system adapted to compensate for the low external temperatures and bring the internal temperature back to the desired range.

In the embodiments where there are two thermal storage units of which one is used for cooling and one is used for heating, the heat exchange ducts of the thermal storage unit(s) for cooling are not connected with the thermal storage unit for heating. The thermal storage unit for heating 250 comprises one or more electric heating resistances 249.

The fans for mixing the air relating to the thermal container for cooling, when present, and the fans for the thermal container for heating also include a programmable electronic control system which controls their operation during the period of thermal autonomy, for example to control their activation, for example as a function of the temperature detected by one or more temperature sensors and/or other parameters detected by suitable sensors.

The electronic control system and the low power fans are powered by batteries housed inside the means of transport which are charged during the thermal charge phase and/or are powered by photovoltaic panels placed on the roof of the vehicle. The batteries powered in this way guarantee an operating autonomy equivalent to the autonomy of the thermal storage system for both cooling and heating.

The electronic system for carrying out the thermal charge is included in the thermal charge apparatus 70 which will be described later.

According to a particularly advantageous combination of features, the heating thermal storage unit 250 comprises a temperature sensor operatively connected to the electronic control system, which is configured to activate and deactivate the one or more electric heating resistances 249 according to the temperature detected by the temperature sensor; in particular the electronic control system is configured to deactivate the electric resistances when a predetermined threshold temperature is reached.

Preferably there are one or more temperature sensors connected to the electronic control system, even more preferably there are: a temperature sensor inside the thermal storage unit 30, 40, 50 and a temperature sensor 12 outside the thermal storage unit to detect the ambient temperature and/or to detect the temperature inside the container 1 .

Optionally, the thermal storage unit 50 for cooling comprises a series of fans 113 configured to distribute the air at low speed inside the container 1 , making its temperature uniform.

These fans 113 are configured to make the air flow over the surface of the thermal storage unit 50, so as to spread it inside the container 1. Advantageously, these fans are activated by an electronic temperature control system powered by batteries housed in the container or by photovoltaic panels installed on the roof of the vehicle or powered by the connection with the vehicle generator.

The thermal storage unit for heating 250 comprises a series of fans 213 configured to distribute the air at low speed inside the container 1 , making its temperature uniform.

For this purpose, in the container 1 , and in the monolithic body 20 thereof, there are passages for the air communicating with the fans 113.

In the preferred and illustrated embodiment, the thermal storage unit 50 comprises a lower ducting element 12 through which the air can enter the container 1 and which also acts as a lower support and as a fastening to the floor of the container.

In the preferred embodiments, the inlet port 91 and the suction port 92 are configured to be connected to a thermal charge apparatus 70 capable of supplying the refrigerant fluid by conveying it towards the heat exchange ducts 33 and to extract it therefrom, for example the aforementioned ports 91 , 92 are provided with hydraulic connectors, such as, for example, quick-coupling connectors of known type.

In fact, during operation, and in particular in a phase of preparation of the temperature-controlled container 1 in which the cooling of the thermal storage material is performed, the container 1 is operatively connected to a thermal charge apparatus 70 which has the function of supplying and cooling the refrigerant fluid and making it circulate in the thermal storage unit 50, 250 (in particular in the heat exchange ducts 33) to cool and preferably solidify the thermal storage material.

A system comprising the temperature-controlled container 1 and such a thermal charge apparatus 70 for performing cooling of the phase change material in the container 1 is also an object of the present invention. The thermal charge apparatus 70 comprises: a delivery port for the injection of the refrigerant fluid into the inlet port 91 , configured to be connected (preferably by means of a flexible hose and quick connection system) to this inlet port 91 , for example by means of a hydraulic connector; a suction port for extracting the cooling fluid from the outlet port 92, configured to be connected (preferably by means of a flexible hose and quick connection system) to this outlet port 92, for example by means of a hydraulic connector; and a cooling circuit configured to cool the refrigerant fluid directed towards the delivery port and coming from the suction port.

Conveniently, the thermal charge apparatus 70 also comprises: an electrical connection for power supply and temperature control during the thermal charge phase for the electrical resistances installed in the second thermal storage unit 50; a connection with one or more temperature probes applied to both the thermal storage unit to control its temperature both during thermal charging and recharging; a connection with one or more internal air temperature probes 12 to control said temperature during the thermal recharging phase with the products inside and to avoid going outside the applicable range.

The cooling circuit can be made so as to preferably comprise an energy supply group, a compressor, a condenser and at least one air extraction fan.

In the preferred embodiments the cooling circuit further comprises: a multipolar cable with connector for the connection between the thermal charge unit and the probes contained in the load unit in order to allow the optimal execution of the thermal charge; a solenoid valve on the delivery and one on the suction to electronically close the delivery duct and to be able to carry out the complete suction of the refrigerant fluid contained in the load unit ("gas evacuation"); a manual valve on the delivery and one on the suction in order to ensure complete sealing of the refrigerant.

The thermal charge apparatus allows the thermal charge of the thermal storage unit for cooling 50 and of the thermal storage unit for heating 250 to be carried out in parallel by feeding the resistances up to the defined temperature of the high-boiling liquid.

According to an optional and advantageous feature, the thermal charge apparatus 70 comprises an external containment structure, preferably comprising a protective shell.

Preferably, the thermal charge apparatus 70 comprises an electronic control system (PLC programmable logic controller) which can be operatively connected to the temperature sensors present in one or more thermal storage units 50 present in the container 1 and preferably also to the electric heating resistances 249 and even more preferably also to the hydraulic system (when present) to control them.

In the preferred embodiments, the electronic control system in the thermal charge apparatus 70 is therefore configured to control (when connected to the container 1 ) the flow of the refrigerant fluid and preferably also the actuation of the electric heating resistances 249 as a function of the temperature detected by the temperature sensors 12 and possibly of the external environmental conditions.

For example, when the outside ambient temperature is low, the container 1 can operate as follows: the container 1 is connected to the thermal charge apparatus 70 to carry out the thermal charge phase before the travel; when the thermal charge apparatus 70 is activated, the refrigerant passes through the heat exchange duct 33 of the thermal storage unit 50, the temperature sensor installed in the thermal storage unit 50 for cooling transfers data to the electronic control system of the thermal charge apparatus 70, and when the predefined temperature value is reached, the electronic control system automatically stops the flow of refrigerant fluid; if the external temperature is below a predetermined threshold, the electric heating resistances 249 of the heating thermal storage unit are activated to increase the temperature of the thermal storage material from the ambient value to the predefined temperature (typically 60- 300°C) to use the heat accumulated in the material for balancing the heat flow through the walls, the temperature sensor installed in the heating thermal storage unit 250 transfers the data to the electronic control system which automatically switches off the electric resistances 249 when the predetermined temperature is reached.

Optionally, the thermal shield installed in the thermal storage system for cooling can be provided with slots that can be opened or closed according to the requirements of the transported load, where food requires 0/+4°C or 10/12°C and pharmaceuticals <-18°C, +2/+8°C, +15/+25°C.

The temperature inside the container 1 is determined by the temperatures of the transition of state of the PCMs used in the different thermal storage units or even in the same when the different types of PCMs are not miscible with each other and is the result of the interaction between the heat transfer modulated by the thermal shield 57 and by the operation of the relative fans, where these are present, by the heat absorption of the thermal storage unit 50 or the heat released by the same thermal storage unit 250 and by the operation of the relative fans, and the heat flow through the walls 23.

In essence, in its general outlines, the method for transporting and/or storing perishable goods in a temperature-controlled container 1 , according to the present invention, comprising the steps of: cooling a refrigerant fluid in an apparatus 70 external to the container 1 (in particular in the thermal charge apparatus 70 described above); passing this refrigerant fluid inside at least one heat exchange duct 33 included in a thermal storage unit for cooling 50 of the container 1 so as to cool the heat storage material, preferably until it changes phase (solidifying it); extracting the refrigerant fluid from the container 1 ; transporting and/or storing perishable goods in container 1 .

Optionally, in case of particularly low external temperatures, the step of heating the thermal storage material contained in the thermal storage unit for heating 250 is also performed in order to maintain the internal temperature at positive values even in the presence of strongly negative external temperatures.

Advantageously, the refrigerant fluid is completely extracted from the container 1 before the transport travel.

In practice it has been found that the temperature-controlled container according to the present invention fulfills the task as well as the pre-established purposes, as it simplifies logistics and avoids the safety problems typical of known active, passive and semi-passive solutions and allows, with a single means, to carry out the transport of products at a controlled temperature, both food and pharmaceutical products, covering the four temperature ranges required by the regulation despite the intrinsic rigidity of state-transition products which have only one melting temperature. This allows for global operational flexibility of the distribution vehicles, making them able to standardize all distribution operations with a single vehicle.

Another advantage of the temperature-controlled container according to the present invention consists in the fact that it is markedly more efficient from an energy point of view.

A further advantage of the temperature-controlled container according to the present invention consists in having a thermal storage capacity which allows both to carry out the direct cooling of the hot products upon harvesting in the field without passing through the blast chillers, and a thermal autonomy which allows end-to-end/field-to-fork transport with a transit time of up to 35 days without interruption of the cold chain and to allow door openings for customs and health inspections even for prolonged periods (typically up to 1 -2 hours) without deterioration of the overall thermal performance, in fact the increase in internal temperature is subsequently reabsorbed in a short time.

Another advantage of the temperature-controlled container according to the present invention consists in being able to operate independently of the availability of an electric network during the travel.

Furthermore, the temperature-controlled container according to the present invention is easy to manufacture and use as well as economically competitive.

The temperature-controlled container thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the attached claims.

Furthermore, all the details may be replaced by other technically equivalent elements.

In practice, the used materials, as well as the contingent shapes and sizes, may be any ones according to the requirements and to the state of the art.

Claims

1. A temperature-controlled container (1 ) for the transport of perishable goods, in particular of the type of a refrigerated container for land and/or maritime transport, characterized in that it comprises: a monolithic box-shaped body (20) that is made of composite material comprising an inner core of an expanded insulating material, covered by an external layer; and a cooling thermal storage unit (30, 40, 50) that is coupled to an inner wall (24) of said box-shaped body (20) and connected in fluid communication to an inlet port (91 ) for the inlet of a refrigerant fluid, and a suction port (92) for the extraction of said refrigerant fluid; wherein said cooling thermal storage unit (30, 40 50) comprises an outer casing (31 , 41 , 51 ) which comprises a thermal storage material consisting of a plurality of different thermal storage liquids having different melting points, in which a heat exchanger (52) is embedded which comprises at least one heat exchange duct (33) adapted to be passed through by the refrigerant fluid that is in transit between said inlet port (91 ) and said suction port (92) wherein said cooling thermal storage unit (30, 40, 50) is provided with a thermal shield (37, 47, 57) fixed to said outer casing (31 , 41 , 51 ), said thermal shield (37, 47, 57) being arranged towards the inside of the temperature-controlled container (1 ) so as to cover the thermal storage unit (30, 40, 50) at least in part.

2. The temperature-controlled container (1 ) according to claim 1 , comprising a plurality of cooling thermal storage units (30, 40, 50) containing different thermal storage liquids having different melting points.

3. The temperature-controlled container (1 ) according to one or more of the preceding claims, further comprising a heating thermal storage unit (250) comprising one or more electrical heating resistances (249) that are immersed in a thermal storage liquid. The temperature-controlled container (1 ) according to the preceding claim, wherein at least said heating thermal storage unit (250) comprises a temperature sensor that is operatively connected to an electronic control system, said electronic control system being configured to activate and deactivate said one or more electrical heating resistances (249), during a phase of thermal charge as a function of the detected temperature by said temperature sensor, deactivating said electrical resistances (249) upon reaching a preset threshold temperature. The temperature-controlled container (1 ) according to one or more of the preceding claims, wherein said cooling thermal storage unit (30, 40, 50, 250) comprises a compressible layer of absorption of the change of volume interposed between said outer casing (31 , 41 , 51 ) and said thermal storage material and configured for absorbing an increase in volume of said thermal storage material due to the phase change as a consequence of cooling, said compressible layer of absorption of the change of volume comprising a plurality of cells adapted to be compressed, and being preferably composed of high-density polyethylene. The temperature-controlled container (1 ) according to one or more of the preceding claims, wherein said heat exchanger (52) further comprises a set of fins or blades (54) each provided with a set of through holes; and wherein the at least one heat exchange duct (33) comprises one or more pipes that pass through said through holes. The temperature-controlled container (1 ) according to the preceding claim, wherein the at least one heat exchange duct (33) comprises a plurality of pipes that are arranged adjacent along parallel planes, each of said pipes forming a coil arranged along a respective plane, wherein each coil comprises linear portions parallel to each other and connected in parallel by means of a delivery manifold, an intake manifold and connecting curved portions; said linear portions of the coils passing through said through holes of the fins or blades (54). The temperature-controlled container (1 ) according to one or more of the preceding claims, wherein the at least one heat exchange duct (33) comprises a plurality of heat exchange ducts hydraulically arranged in parallel. The temperature-controlled container (1 ) according to one or more of the preceding claims, wherein the thermal shield (37, 47, 57) is fixed to the outer casing (31 , 41 , 51 ) of the thermal storage unit (50) by means of spacer and support elements coupled to said outer casing (31 , 41 , 51 ). The temperature-controlled container (1 ) according to one or more of the preceding claims, wherein the thermal shield (57) comprises a shutter for regulating the flow of natural convection and/or ventilation. The temperature-controlled container (1 ) according to one or more of the preceding claims, wherein the cooling thermal storage unit (50) comprises a set of fans (113) configured to distribute air at low speed inside the temperature-controlled container (1 ). A temperature-controlled container (1 ) for the transport of perishable goods, in particular of the type of a refrigerated container for land and/or maritime transport, characterized in that it comprises: a monolithic box-shaped body (20) that is made of composite material comprising an inner core made of an expanded insulating material, covered with by an external layer; and a plurality of cooling thermal storage units (30, 40, 50) that are coupled to respective inner walls (24) of said box-shaped body (20) and connected in fluid communication to an inlet port (91 ) for the inlet of a refrigerant fluid, and a suction port (92) for the extraction of said refrigerant fluid; wherein each of said cooling thermal storage units (30, 40, 50) comprises a respective outer casing (31 , 41 , 51 ) which comprises a respective thermal storage material, in which a respective heat exchanger (32, 42, 52) is embedded which comprises at least one heat exchange duct (33) adapted to be passed through by the refrigerant fluid that is in transit between said inlet port (91 ) and said suction port (92), wherein each of said cooling thermal storage units (30, 40, 50) is provided with a respective thermal shield (37, 47, 57) fixed to said outer casing (31 , 41 , 51 ), said thermal shield (37, 47, 57) being arranged towards the inside of the temperature-controlled container (1 ) so as to cover the thermal storage unit (30, 40 50) at least in part, wherein said cooling thermal storage units (30, 40, 50) contain different thermal storage liquids having different melting points. A system comprising a temperature-controlled container (1 ) according to one or more of the preceding claims and a thermal charge apparatus (70) to perform the cooling of the thermal storage material in said temperature-controlled container (1 ), said thermal charge apparatus (70) being adapted to supply said refrigerant fluid by conveying it towards the at least one heat exchange duct (33) and to extract it therefrom, said system being characterized in that it comprises: a delivery port for the injection of refrigerant fluid in said inlet port (91 ), configured to be connected to said inlet port (91 ); a suction port for the extraction of the refrigerant fluid from said outlet port (92), configured to be connected to said outlet port (92); a cooling circuit configured for the cooling of said refrigerant fluid that is directed towards said delivery port and coming from said suction port. A method for transporting and/or storing perishable goods in a temperature-controlled container (1 ) according to one or more of claims 1 to 12, characterized in that it comprises the steps of: cooling a refrigerant fluid in an apparatus (70) that is external to said temperature-controlled container (1 ); allowing said refrigerant fluid in a thermal storage unit (50) of the temperature-controlled container (1 ) so as to cool said thermal storage material; extracting said refrigerant fluid from the temperature- controlled container (1 ); transporting and/or storing the perishable goods in the temperature-controlled container (1 ). The method according to the preceding claim, further comprising the step of heating the thermal storage material that is contained in a heating thermal storage unit (250) in order to maintain the inner temperature at positive values when the outer temperature is negative.