FR2771478A1 - Regulation of temperature of items stored inside refrigerated enclosure - Google Patents

Abstract

The temperature in the upper part (9) of the chamber is gathered by transducers (8,8') near the top of the chamber, and temperature in the lower part (11) is gathered by transducers (10,10') near the bottom of the chamber. A supplementary transducer (13) measures temperature outside the chamber. A processing unit (7) combines temperature data, and adjusts the refrigeration unit accordingly.

Description

 The invention relates to an installation for regulating, with respect to a set temperature, the temperature of a load placed inside a refrigerated enclosure, said installation comprising, on the one hand, means for lifting the the temperature and, on the other hand, cooling means, these means being connected to a central processing unit. The present invention also relates to a method for managing the operation of such a regulation installation.

 The present invention relates to the field of storage and preservation in a refrigerated environment of a large volume of food products.

 In fact, this invention will find, more particularly, its application in the field of the preservation of fragile food products and requiring particular and relatively strict conditions of temperature and humidity. This is actually the case when it is a question, for example, of storing a potato so that it retains all its taste qualities but also aesthetic qualities, both external and internal.

 Also, when it comes to preserving perishable and particularly fragile food products, it is known to use refrigerated premises, such as cold rooms. In fact, it turns out that, if the temperature regulation of small or medium-sized premises can be done relatively efficiently and effectively, such regulation causes a certain number of problems when one is in the field the storage of very large quantities of food products inside particularly large premises and refrigerated by means of an industrial cold station.

 Indeed, such premises have a floor area as well as a significant ceiling height defining a substantial volume to be refrigerated. Also, these premises include cooling means which are, in most cases, in the form of evaporators installed on the ground and capable of producing cold air which will be distributed, by appropriate means, throughout the room.

 In fact, it will be noted that the storage of food products in such a room is generally done by placing them inside containers or the like which represent, on the one hand, an obstacle to the progression and the spread of the product. cold air and, on the other hand, a factor of inertia when warming up these products. It should also be remembered that for reasons of density, the cold air emanating from the evaporators placed on the ground will tend to accumulate in the lower part of such a room.

 It follows from the above that the temperature inside said room is not homogeneous and that the temperature differences noted at different points in this volume can be significant.

Incidentally, it should now be recalled that the conservation of certain food products, in particular potatoes, imposes particularly strict and restrictive temperature conditions which admit only a slight deviation from a temperature of instructions. Indeed, such potatoes can be stored between 5 and 70 C depending on the oe varieties, which limits germination and prevents drying out. As an example, it will be noted that below these temperature values, the starch of the tubers transforms into sugar, which alters their taste and colors them. It therefore follows that the storage and refrigeration conditions of such potatoes must be particularly well controlled and that the temperature differences between the various storage points are particularly detrimental to the quality of the tubers.
Another drawback of this type of installation concerns, for example, the quality of the temperature regulation with respect to a set temperature. In fact, such regulation is generally carried out through a single temperature reading compared with a set temperature for the purpose of switching on the various cooling means. It will be noted that this temperature reading is not really representative of the temperature of the charge to be refrigerated. In addition, the temperature sensor, with the help of which said reading is carried out, is often placed near the side walls, the ceiling or the floor of the room which, on the one hand, does not effectively account for the temperature prevailing at the level of the charge to be refrigerated and, on the other hand, absolutely does not take account of the inertia with respect to cooling - heating of said charge.

 The present invention is intended to provide a solution to the problem mentioned above.

 To this end, the invention relates to an installation for regulating, with respect to a set temperature, the temperature of a charge placed inside a refrigerated enclosure, said installation comprising, on the one hand, means for raising the temperature and, on the other hand, means for cooling, these means being connected to a central processing unit, characterized in that the said means for raising the temperature comprise at least one sensor disposed in the upper part 1 refrigerated enclosure and capable of reading an internal temperature and at least one sensor disposed in the lower part of said refrigerated enclosure and capable of reading an internal temperature.

 According to another characteristic of the present invention, said cooling means are in the form of external air supply means and a device for producing cold air. The latter can be supplemented by ventilation means capable of ensuring better homogenization of the cold air inside the refrigerated enclosure.

 More particularly, it will be observed that the or one of the sensors disposed in the upper part of the refrigerated enclosure and / or the or one of the sensors disposed in the lower part of the refrigerated enclosure is implanted in the charge contained by the latter. .

The present invention also relates to a method for managing the operation of an installation in accordance with the present invention. This process is intended for regulating, with respect to a set temperature, the temperature of a load placed inside a refrigerated enclosure. Such a method is characterized in that
- the internal temperature of the refrigerated chamber and the temperature outside it are noted
- the setpoint temperature is compared to the internal temperature and, if the latter is higher than the setpoint temperature, this setpoint temperature is also compared to the outside temperature
- We intervene on different cooling means according to values of internal temperature and / or outside temperature and predetermined set temperature.

 In fact, by means of several sensors, several temperature readings are taken in the upper part of the refrigerated enclosure and the average of these internal recorded temperatures is taken. The same is done in the lower part of said enclosure to obtain a second average internal temperature.

 The advantages arising from the present invention consist in that it is possible to evaluate, with precision and at a certain number of strategic points, the temperature inside the refrigerated enclosure as well as its evolution taking into account, more particularly, the temperature at the very heart of the charge contained in said enclosure.

 It will be noted that the cooling means can be of different types and take the form of a device for producing cold air which can advantageously be supplemented by means of ventilation. In addition, it is also possible, when the atmospheric conditions allow it, to ensure the cooling of the premises by allowing inside air to enter, by means of external air supply means thus avoiding switch on the previously mentioned cold air production device.

 Finally, this temperature regulation installation includes a processing unit which, on the basis of the temperatures recorded by the temperature reading means, are able to control the various cooling means. As will appear during the description, such processing means are in the form of a computer system capable of managing the operation of the entire installation for regulating the temperature in a particularly precise manner. , effective and advantageous.

 Other objects and advantages of the present invention will emerge during the description which follows, relating to an embodiment which is given only by way of an indicative and nonlimiting example.

The understanding of this description will be facilitated by referring to the attached drawings and in which
- Figure 1 corresponds to a schematic view of the installation, object of the present invention
- Figure 2 illustrates, in the form of a flowchart, the different steps of the process for managing the operation of such an installation
- Figure 3 corresponds to a more detailed flowchart of this management process.

 The present invention relates to the field of conservation and storage of products, in particular of the food type, in refrigerated premises.

 More particularly, this is an installation 1 for regulating, with respect to a setpoint temperature TC, the temperature T of a load 2.

 In fact, as represented in FIG. 1, such an installation 1 is in the form of a refrigerated enclosure 3 inside which said load is placed 2. The setting, the maintenance as well as the regulation of the internal temperature TI of this refrigerated enclosure 3 are provided by means of temperature regulation. In fact, said installation 1 comprises such means of regulation which then usually take the form of means for raising the temperature 5, cooling means 6 as well as a central processing unit 7 connected to these means 5 and 6. This central processing unit 7 is able to manage and control the cooling means 6, the operation of which is then conditioned by the temperature values recorded through the lifting means 5.

 According to the invention, these means 5 for raising the temperature comprise at least one sensor 8, 8 ′ ... disposed in the upper part 9 of said refrigerated enclosure 3 and capable of detecting an internal temperature TI1, Tu1 '... These lifting means 5 also comprise at least one sensor 10, 10 '... arranged in the lower part 11 of said refrigerated enclosure 3 and capable of reading an internal temperature TI2, Tir' ...

 In fact, it should be specified here that said installation 1 is intended to cool a load 2 consisting of food products, more particularly potato. The latter are particularly fragile and tend to flatten when stacked in bulk and on a pile exceeding a certain height. Also, in order to overcome this problem, these potatoes are placed inside boxes 12 even being stacked on top of each other. It is then possible to reach, by this means, storage heights of several meters clearly exceeding those of a conventional stacking in heaps and in bulk. Such boxes 12 have the advantage of being able to be handled with ease, in particular by forklifts, which facilitates transshipment.

 The boxes 12, placed side by side and stacked, then contain the potatoes which constituting, substantially, the load 2 of food products which it is a question of refrigerating.

 According to an advantageous embodiment, the or at least one of the sensors 8, 8 '... disposed in the upper part 9 of the refrigerated enclosure 3 and / or the or at least one of the sensors 10, 10' ... arranged in the lower part 11 of the refrigerated enclosure 3 is installed in the load 2, inside the volume defined by the latter, which being, moreover, contained by said refrigerated enclosure 3.

 This or these sensors 8, e '..., respectively 10, 10' ..., arranged inside said volume, then makes it possible to take an internal temperature TI1, TT1, ..., respectively TI2, TI2 '. .., representative of the temperature T of the load 2 in the upper part 9, respectively lower 11, of the enclosure 3.

 According to a preferred embodiment shown in FIG. 1, there are, in the upper part 9 of the enclosure 3, several sensors 8, 8 ′ ... capable of reading the internal temperatures TI1, TI1, ... for which the average to obtain an average internal temperature TD ?. It is also possible to do the same in the lower part 11 of the enclosure 3 by having several sensors 10, 10 ′ .. reading the internal temperatures TI2, TI2 ... from which an average internal temperature TI>? Is calculated.

 It is obvious that the average internal temperatures Tfl and TZMZ thus calculated are all the more significant as the number of sensors 8, 8S ...; 10, 10 '... is high. In this regard, it will be noted that very good results have been obtained for five sensors.

 The means 5 for raising the temperature can, in addition, be supplemented by an additional sensor 13 disposed outside the refrigerated enclosure 3 and capable of detecting and transmitting to the central processing unit 7 an outside temperature TE characteristic of the weather conditions.

 As regards, now, the central processing unit 7, the latter is able to receive information from the lifting means 5 to which it is connected. This central processing unit 7 comprises storage means 14 for the information transmitted by the sensors 8, 8 '... 10, 10' .. and 13 as well as means 15 for managing the temperatures recorded by the latter. In fact, these management means 15 as well as, possibly, the storage means 14, are able to know a setpoint temperature TC as well as a reference temperature TR. Such management means 15 are capable of transmitting information to control means 16 of the cooling means 6, said control means 16 further coming to complete said central processing unit 7.

 It will also be observed that the latter can still be supplemented by display means 17 for the different temperatures and their evolution. In fact, it will be observed that, according to a preferred embodiment, this central processing unit 7 is in the form of a microcomputer 18 capable of integrating one or more of the means 14 to 17 previously mentioned.

 For questions of wiring and ease of connection of the sensors 8, 8 '..., 10, 10' ... and 13, the refrigerated enclosure 3 can be provided, in its internal part 19, with connection boxes 20 connected to the central processing unit 7 and to which each of said sensors 8, e '..., 10, 10' ... and 13 corresponding to the temperature reading means 5 can be individually connected.

 As already mentioned above, the central processing unit 7 comprises control means 16 able to control cooling means 6. The latter are, in the present case, in the form of a device for producing cold air 21 supplemented by means for supplying outside air 22.

 In fact, said device for producing cold air 21 consists, for example, of one or more evaporators 23 arranged, substantially, at ground level 24 of the refrigerated enclosure 3. This device 21 can advantageously be supplemented by means of ventilation 25 capable of ensuring homogenization of the cold air inside the cooling enclosure 3. In fact, such ventilation means 25 are in the form of one or more ventilation ducts 26 in taken, in their lower part, on the cold air production device 21 and opening, at their upper end, in the upper part 9 of said enclosure 3, in particular near the ceiling 27 of the latter. Such ducts 26 are then able to convey the cold air coming from the device 21, to propel this air above, or even in the upper part of the boxes 12, to distribute it in the upper part 9 of said refrigerated enclosure 3 before that -this returns, through said boxes 12, to the device 21.

The present invention also relates to a method for regulating, with respect to a set temperature TC, the temperature T of a load 2 disposed inside a cooling enclosure 3. Such a method is shown diagrammatically in FIG. 2 and is implemented by means of regulation described above. I1 is characterized by the fact that
- the internal temperature TI of the refrigerated chamber 3 is noted as well as the external temperature TE to the latter
- the setpoint temperature TC is compared with the internal temperature TI and, if the latter TI is higher than the setpoint temperature TC, this setpoint temperature TC is also compared with the outside temperature TE
- We intervene on different cooling means 6 according to internal temperature values TI and / or outside temperature TE and set temperature TC predetermined.

 More specifically, the internal temperature TI of the refrigerated enclosure 3 is noted, in the upper part 9 of the latter, using at least one sensor 8, 8 '. Capable of providing an internal temperature TIl, T11 , .. The same is done in the lower part 11 of said enclosure 3 using at least one sensor 10, 10 '... capable of providing an internal temperature TI2, TI2' ... Likewise, the outside temperature TE at the refrigerated enclosure 3 is recorded using an additional sensor 13.

The internal temperature (s) TIl, T11, ... and / or TI2, TI2, ... are then compared to the set temperature TC and
1) when the internal temperatures compared with TC, as the case TI1, TI1, ... and / or TI2, TI2, ... are greater than or equal to the set temperature TC, we compare the latter TC with the outside temperature YOU
a / If the outside temperature TE is higher than the setpoint temperature TC or if TE is lower than TC and, at the same time, TE is lower than a reference temperature TR, we ensure the start-up of a production device d cold air 21 as well as that of ventilation means 25 associated with said device 21
b / if the outside temperature TE is, on the one hand, lower than the setpoint temperature TC and, on the other hand, higher than the reference temperature TR, the supply of outside air supply means is ensured 22
2) when the internal temperatures compared to TC, as the case TI1, T11, .. and / or TI2, TI2, .. are lower than the setpoint temperature TC, the temperature differential T11 - T12, TI1'- is measured TI2 ', ..., this differential is compared to a determined temperature value #T and, when this differential is greater than AT, ventilation means 25 are triggered.

 The process described above has been illustrated in FIG. 3.

 According to a preferred embodiment, there is a plurality of sensors 8, 8 '... in the upper part 9 and a plurality of sensors 10, 10' .. in the lower part 11 of the refrigerated enclosure 3.

In this case, the average internal temperatures are calculated
TI1, TI1, ... recorded by said sensors 8, 8 '... which makes it possible to obtain an average internal temperature TIM1 that 1' is equal to the internal temperature TI1. The same is done for the internal temperatures TI2, TI2 '... recorded, in this case, by the sensors 10, 10'. . . in order to obtain an average internal temperature TSM2 which is equal to the internal temperature TI2.

Thus, we assimilate an average internal temperature TIM2 respectively, to an internal temperature TI1, respectively
TI2, with a view to their comparison with the setpoint temperature TC and the calculation of the temperature differential T11 - T12 during the course of the process described above.

 For example, food products, such as potatoes, are stored between 5 "C and 70 C depending on the variety. The set temperature TC is then between 50C and 70C.

 As regards, now, the outside air supply means 22, these are preferably called to cool said refrigerated enclosure 3 when the temperature of the outside air TE is between 0.50C and 1, 50C less than the set temperature TC. Thus, for example, if this setpoint temperature TC is 6 "C, the supply means 22 are requested for an outside temperature TE of between 4.5 and 5.50C.

 In the same order of idea and as it was mentioned in the introductory part, the temperature T of the charge should not be too low under penalty of alteration of the taste and the color of the tubers. Also, the reference temperature TR above which the external air supply means 22 are actuated is preferably chosen to be equal to OOC.

 In fact, the storage conditions for potatoes require particularly rigorous management of the refrigeration temperature. As a result, the temperature difference AT is relatively small and is of the order of 0.5 "C in summer and 0.30C in winter.

 As already mentioned above, the operation of such an installation can, advantageously, call upon a computer tool which authorizes particularly efficient and effective temperature regulation, all the more so since this tool is capable of to intervene on cooling means which, themselves, are particularly efficient.

 Although the invention has been described in connection with an embodiment, it is understood that it is in no way limited thereto and that various modifications, forms, materials and combinations of these can be made to it. various elements, without departing from the scope and spirit of the invention.

Claims (10)

Claims  1. Installation for regulating, with respect to a set temperature (TC), the temperature (T) of a load (2) disposed inside a refrigerated enclosure (3), said installation (1) comprising, on the one hand, means for raising the temperature (5) and, on the other hand, cooling means (6), these means (5, 6) being connected to a central processing unit (7) , characterized in that the said means for raising the temperature (5) comprise at least one sensor (8, 8 ′ ...) disposed in the upper part (9) of the said refrigerated enclosure (3) and capable of detecting a temperature internal (TIl, T11, ...) as well as at least one sensor (10, 10 '...) arranged in the lower part (11) of said refrigerated enclosure (3) and capable of detecting an internal temperature (TI2, TI2 '...).  2. Installation according to claims 1, characterized in that the lifting means (5) are supplemented by an additional sensor (13) disposed outside the refrigerated enclosure (3) and able to pick up and transmit to the central processing unit (7) an outside temperature (TE).  3. Installation according to any one of the preceding claims, characterized in that the or at least one of the sensors (8, 8 '...) disposed in the upper part (9) of the refrigerated enclosure (3) and / or the or at least one of the sensors (10, 10 '...) disposed in the lower part (11) of the refrigerated enclosure (3) is installed in the load (2) contained by the latter (3 ).  4. Installation according to any one of claims 2 or 3, characterized in that the central processing unit (7) comprises storage means (14) of the information transmitted by the sensors (8, 8 '... ; 10, 10 '...; 13) as well as means (15) for managing the temperatures recorded by the latter and means (16) for controlling the cooling means (6).  5. Installation according to any of claims 2 to 4, characterized in that the refrigerated enclosure (3) is provided, in its internal part (19), with connection boxes (20) connected to the central unit treatment (7) and to which each of the sensors (8, 8 '...; 10, 10' ..; 13) can be connected individually.  6. Installation according to any one of the preceding claims, characterized in that the cooling means (6) consist of a device for producing cold air (21) supplemented by means for supplying outside air (22 ).  7. Installation according to claim 6, characterized in that the cold air production device (21) is supplemented by ventilation means (25) in the form of one or more ventilation ducts (26) and able ensure homogenization of the cold air inside the refrigerated enclosure (3).  8. Method for regulating, with respect to a set temperature (TC), the temperature (T) of a load (2) disposed inside a refrigerated enclosure (3), characterized in that  - the internal temperature (TI) of the refrigerated enclosure (3) is noted as well as the external temperature (TE) at the latter  - the set temperature (TC) is compared to the internal temperature (TI) and, if the latter (TI) is higher than the set temperature (TC), this set temperature (TC) is also compared to the outside temperature (TE)  - We intervene on different cooling means (6) according to values of internal temperature (TI) and / or outside temperature (TE) and set temperature (TC) predetermined.  9. Method according to claim 8, characterized in that  - the internal temperature (TI) of the refrigerated enclosure (3) is noted, in the upper part (9) of the latter, using at least one sensor (8, 8t, etc.) capable of providing a internal temperature (TI1, T.1 ....) and, in the lower part (11) of said enclosure (3), using at least one suitable sensor (10, 10 '...) to provide an internal temperature (TI2, TI2, ...)  - using an additional sensor (13), the outside temperature (TE) at the refrigerated enclosure (3) is noted  - we compare the internal temperature (s) (TI1, TI1, ...) and / or (TI2, TI2, ...) to the set temperature (TC) and: 1) when the internal temperatures compared to (TC) ,, depending on the case (TI1, TI1s ...) and / or (TI2, TI2, ...) are greater than or equal to the set temperature (TC), we compare the latter (TC) to the outside temperature ( TE);  a / If the outside temperature (TE) is higher than the set temperature (TC) or if (TE) is lower than (TC) and, simultaneously, (TE) is lower than a reference temperature (TR), we ensures the start-up of a device for producing cold air (21) as well as that of ventilation means (25) associated with said device (21);  b / if the outside temperature (TE) is, on the one hand, lower than the set temperature (TC) and, on the other hand, higher than the reference temperature (TR), we ensure that the external air supply means (22)  2) when the internal temperatures compared with (TC), as appropriate (TI1, TI1, ...) and / or (TI2, TI2, ...) are lower than the set temperature (TC), the temperature differential 9TI1 - TI2, TI1, - TI2, ...), we compare the latter to a determined temperature value (AT), and, when this temperature differential (TI1-TI2, ...) is greater than (#T), the ventilation means (25) are triggered.  10. Method according to claim 9, characterized in that the internal temperature (TI1), respectively (TI2), is equal to the average internal temperature (TIM1), respectively (TIM2), obtained by averaging the internal temperatures ( TI1, TI1, ...), respectively (TI2, TI2, ...), detected by a plurality of sensors (8, 8 '...), respectively (10, 10' ...), arranged in the upper part ( 9), respectively in the lower part (11), of the refrigerated enclosure (3).