FR3073936A1 - HUMIDITY MANAGEMENT SYSTEM, REFRIGERATED CABINET COMPRISING SUCH A SYSTEM AND METHOD OF REGULATION - Google Patents

Abstract

This system (S) for managing the ambient humidity of a refrigerated enclosure (100) of small volume, comprises a refrigerating system controlling the ambient air temperature of the refrigerated enclosure, a control system. humidifying (140) the ambient air of the refrigerated enclosure, a humidity measuring system (150), and a regulating unit (160) controlling the refrigerating system and the humidification system according to data recorded by the the humidity measuring system so as to humidify or dehumidify the ambient air of the refrigerated enclosure.

Description

Humidity management system, refrigerated cabinet comprising such a system and method of regulation

The present invention relates to a system for managing the humidity of the ambient air in a refrigerated enclosure of small volume. The invention also relates to a refrigerated cabinet comprising such a system, as well as to a control method implemented by such a system.

For optimal wine aging, the temperature and humidity parameters must be closely controlled. If everyone knows that poor temperature management causes poor aging of the wine, the effect of humidity is less known to the general public while this parameter is of primary importance. If the humidity is too low, the air may come into contact with the wine and deteriorate it. Too high a humidity causes mold on the cork, thus risking contaminating the wine. The label also deteriorates in high humidity environments. This detracts from the aesthetics and therefore the value of a bottle.

The refrigeration unit of an existing cellar is controlled by temperature regulation. The optimum temperature for aging wine is around 12 ° C. Thus in refrigerated cellars, this value is closely monitored to limit temperature variations in the enclosure. Some cellars are already equipped with a humidity control system. However, on the current market, manufacturers independently manage temperature and relative humidity. In addition, in the field of refrigeration and air conditioning, systems often respond to humidity problems in the field of large volume refrigeration. In fact, the patents FR2945108, FR2819880, FR2701485 and US8161761 put forward an air conditioning system allowing total management of air humidity in large volume enclosures (> 2 m ³ ) for aging or keeping wine.

Due to the low air volume and low temperature, managing and controlling the humidity of small refrigerated cabinets is very complex. Current refrigerated cabinets therefore do not have humidity control. For example, several patents on the management of humidity in refrigerated enclosures have been issued without controlling the relative humidity of the air. In the field of wine aging, there are many patents relating to moisture management. However, humidification and dehumidification are often separated. For example, patent W02007 / 003808 A2 puts forward a humidification system for a bottle storage cabinet. The device allows humidification of the cabinet by natural convection on an absorbent material saturated with water. Humidification control is however not possible. Patent W02004 / 051151 A1 relates to an ultrasonic air humidification device. The system includes a water nebulizer and an air mixing device. This system like the previous one only allows humidification of an enclosure. This system is nevertheless controlled and the volume of air involved is large (> 2 m ³ ). Several dehumidification systems are used in the regulation of room humidity (large volume). The systems presented in patents FR3001528, FR2897420, US6755118 are all air extraction devices. That is, moisture is extracted when the outside environment is drier than the inside. Air drying is also a problem in refrigerated cabinets.

Systems for the total management of air humidity in small refrigerated cabinets (<2 m ³ ) do not exist. In the field of air conditioning, many total humidity management systems are developed. However, these systems are very expensive and are not viable for use in low volume refrigerated cabinets. Compactness is a real problem for this type of application.

It is to these drawbacks that the invention intends to remedy by proposing a new system for managing the humidity of a refrigerated cabinet of small volume, allowing better conditions of wine conservation than the systems of the prior art.

To this end, the invention relates to a system for managing the humidity of the ambient air of a small refrigerated enclosure, comprising:

- a refrigeration system controlling the temperature of the ambient air in the refrigerated enclosure,

- a system for humidifying the ambient air in the refrigerated enclosure,

- a humidity measurement system,

- a regulation unit controlling the refrigeration system and the humidification system according to data collected by the humidity measurement system so as to humidify or dehumidify the ambient air of the refrigerated enclosure.

Thanks to the invention, the humidity can be controlled in a small volume enclosure, for optimal conservation of its content.

According to advantageous but not compulsory aspects of the invention, such a management system can incorporate one or more of the following characteristics, taken in any technically admissible combination:

- The humidification system includes a water tank and a ventilation system forcing the passage of air into the water tank.

- The refrigeration system is used for cooling and dehumidifying the ambient air in the refrigerated enclosure.

- The management system also includes a system for circulating ambient air inside the cabinet, controlled by the control unit so that it can be deactivated.

The invention also relates to a refrigerated enclosure of small volume, such as a refrigerated cabinet for the conservation of wines, comprising a management system as mentioned above.

The invention also relates to a method for regulating the humidity of the ambient air of a refrigerated enclosure of small volume, characterized in that it uses, for regulating the humidity of the ambient air of the enclosure, the absolute humidity value, or the dew temperature, or another parameter coupling the temperature value to the relative humidity value.

According to advantageous but not compulsory aspects of the invention, such a regulation process can incorporate one or more of the following characteristics, taken according to any technically admissible combination:

- The method implements a regulation system comprising a refrigeration system, a system for humidifying the ambient air of the refrigerated enclosure, a temperature and humidity measurement system, and a regulation unit controlling the system. and the humidification system based on data recorded by the temperature and humidity measurement system, and comprises steps consisting in:

a) initiate a dehumidification step when a humidity value exceeds a higher threshold value, until the humidity decreases below a value below the upper threshold value and greater than or equal to a set value ;

b) initiate a humidification step when a humidity value falls below a lower threshold value, until the humidity increases above a value greater than the lower threshold value and less than or equal to the setpoint.

- In step a), the refrigeration system is activated to dehumidify when the ambient air temperature in the refrigerated enclosure is higher than a set temperature.

- In step b), the humidification system is activated when the refrigeration system is not switched on.

- The regulation system includes a brewing system, and in step a), the brewing system is deactivated to dehumidify.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of a humidity management system, a refrigerated cabinet and a regulation method. in accordance with its principle, made by way of nonlimiting example with reference to the appended drawings in which:

- Figure 1 is an exploded perspective view of a refrigerated cabinet according to the invention.

- Figure 2 is a perspective view of a chute covering a water tank and a fan belonging to a humidity management system according to the invention.

- Figure 3 is an exploded view of Figure 2.

- Figure 4 is a flow diagram for regulating requests for humidification and dehumidification on absolute humidity illustrating a regulation process according to the invention.

- Figure 5 is a flow chart of general regulation in temperature and humidity illustrating the method of regulation according to the invention.

- Figure 6 is a psychrometric diagram of the temperature and humidity requirement areas illustrating the regulation process according to the invention.

Figure 1 shows a refrigerated cabinet 100, in particular for the storage and preservation of wine bottles. This cabinet 100 is composed of a chest 120 serving as a receptacle for foodstuffs, a refrigeration system and a resistance not shown, a ventilation system 170 dedicated to the mixing of the ambient air contained in the cabinet 100 , a humidification system 140, temperature and humidity sensors 150 as well as an electronic regulation unit 160 ensuring the regulation of the elements of the cabinet 100.

The safe 120 provides the mechanical strength of the enclosure as well as thermal insulation. The door opening the enclosure is either full or glazed.

The refrigeration system present on refrigerated cabinets is, in most cases, a refrigeration machine by compression of refrigerant. However, other cold production systems exist, such as adsorption refrigeration systems, magnetic cold, thermoelectricity, etc. As in the domestic refrigerator market, the compression refrigeration machine is the most common on the wine cellar market. This system is composed of several main elements which are not shown: a compressor, an evaporator, a pressure reducer or capillary, a condenser and a heat transfer fluid.

The ventilation system 170 ensuring air circulation makes it possible to limit the temperature dispersion of the bottles. This consists for example of two fans 171 and 172 allowing the continuous circulation of the air in the refrigerated cabinet.

The resistance allows the enclosure to be heated when the outside temperature is lower than the set temperature of cabinet 100.

The electronic regulation unit 160 makes it possible to control the actuators as a function of the incoming data, that is to say the setpoint data: temperature and relative humidity.

The invention relates to two points, one on the regulation of humidity and the other more specifically on the humidification system. The refrigerated cabinet 100 cannot contain an air conditioning or air treatment system because of its small volume. The chamber temperature control actuators are reused for humidity regulation. This regulation acts on various elements mentioned above.

The cabinet is regulated according to temperature and relative humidity setpoints. However, the temporal fluctuations of the relative humidity are large due to the condensation of water during the activation of the refrigeration system.

For example, a cabinet accommodating a volume of air of 1m ³ whose temperature is 10 ° C and relative humidity of 70% RH contains a mass of water of 5.3g. If 3g of water condenses on activation of the refrigeration system, the relative humidity then drops to 30% RH. This is why, in enclosures with low air volume and where the temperature is "cold" (below 25 ° C), it is difficult to regulate the relative humidity. For this reason, the humidity management system uses absolute humidity instead of relative humidity. The transition equation governing the relationship between relative humidity and absolute humidity is:

622 (^ 610.78 Λ ^{7 27} γ ^ 3Τ ^)

M = -610.78

HA: Absolute humidity

RH: Relative Humidity (measured)

T: Chamber temperature (measured)

Patm: Atmospheric air pressure

The absolute humidity quantity is commonly used for humidity management in the air conditioning sector. For example, patents FR3001528, WO2012124367, GB2524713 or W02006126572 use the magnitude of absolute humidity rather than relative humidity to regulate the humidity of air.

For the electronic control unit 160, temperature control always takes priority over absolute humidity control.

The cabinet 100 includes a humidity management system S which includes an additional component in the refrigerated cabinet: the humidification system 140. FIG. 2 shows the humidification system 140 in assembled configuration. This 140 humidification system is compact and allows humidification of a refrigerated enclosure for several months, even in extreme conditions (desert and / or cold conditions).

The humidification system 140 is composed of a water tank 111, a chute 108 serving as a sheath for the water tank 111 and a ventilation system. In this example, the ventilation system is formed by a centrifugal fan 104. The fan 104, placed near the water tank 111, allows the overall humidification of the ambient air contained in the cabinet. The chute 108 is fixed in the cabinet 100, and the tray 111 is removable by sliding to allow filling with water by a user.

The fan 104 is embedded in a deep-drawn stamp 107, which allows the fan 104 to be brought closer to the water in the water tank 111. For example, the centrifugal fan 104 is held fixed on the chute 108 by a tongue 102 and two inserts not shown. Any other fixing system can be envisaged. The chute 108 serving as a receptacle for the water tank 111 is fixed to a lower sheet (not shown). With the humidification system 140 thus mounted, only one facade 112 of the tank 111 is visible. The holes 106 and 110 of the chute 108 and the water tank 111 are aligned. When the fan 104 is switched on, it forces the passage of air from the interior environment to the surface of the water in the water tank 111. The air saturated with water in the tank 111 is therefore sucked in or discharged in the direction of the chest 120.

As a variant, the ventilation system of the humidification system 140 may comprise more than one fan, or else not comprise a fan and be formed by an air intake orifice.

The humidity requirements are dependent on the external environment of the cabinet 100. For dry outdoor environments, the refrigerated cabinet 100 uses the humidification system 140 to maintain good relative humidity inside the refrigerated cabinet. . However for neutral and humid atmospheres, the refrigerated enclosure presents an air whose relative humidity is equal to or higher than the set point. The management system must imperatively not humidify the refrigerated cabinet. That is to say that the water present in the tank 111 should not evaporate. The humidification is controlled so that the humidification system 140 does not over-humidify the cabinet.

To prevent the user from having to fill the tank 111 too often, the natural evaporation of water from the tank 111 has been limited to the minimum so that its autonomy is the greatest. To limit the passive consumption of water by natural evaporation, the water tank 111 is equipped with a single passage hole 110 of reduced diameter, allowing the passage of the air contained in the water tank 111 sucked in by the fan. 104. The insertion of the water tank 111 into the chute 108 makes it possible to prevent the water from being in the open air and reduces natural evaporation. As a variant, the water tank can include several holes 110 for air passage.

The water tank 111 comprises a plate 203 covering the entire tank. This plate 203 seals the water tank 111. The plate 203 avoids the spillage of water during handling of the tank (water filling). The capacity of the water tank 111 can be, for example, 800 ml. Tray 111 can best meet the needs of low volume refrigerated enclosures.

Figure 4 shows the management of triggering and triggering requests for action on humidity. This graph shows the state of a dehumidification request 1 and the state of a humidification request 2 as a function of the absolute humidity value 13. The regulation defined in this invention makes it possible to adjust the absolute humidity 13 around a set value 7. The dehumidification request 1 goes to the value 1 when the absolute humidity value 13 exceeds a threshold value HA_sup + 11. A dehumidification step 12 is then started until the value d absolute humidity 13 is less than a HAsup value 9. When this HA sup 9 value is reached, the dehumidification request 1 changes to value 0. The difference between the values HA sup 9 and HA_sup + 11 defines a Hysteresis_sup regulation tolerance 10.

When the absolute humidity 13 drops below a threshold value HAinf- 3, the humidification request 2 goes to a value 1 and starts a humidification step 4 until the absolute humidity value 13 reaches a value HA inf 6 greater than the value HA inf- 3. As for the dehumidification step 12, the humidification step 4 admits a regulation tolerance Hysteresis 5, defined between the value HA inf- 3 and the HA value inf 6.

A neutral zone 8 is centered on the set value 7 and delimits the difference separating the value HA inf 6 and the value HA sup 9. The value HA sup 9 is greater than or equal to the set value 7, and the value HA inf 6 is less than or equal to the set value 7.

If the dehumidification request goes to value 1, then the regulation system S acts on the refrigeration system. Switching on the refrigeration system compressor cools the refrigerated cabinet 100 via the refrigeration system evaporator, thereby allowing the water in the air to condense and therefore lower the relative humidity. The refrigeration system is therefore used to dehumidify the ambient air in the enclosure.

Optionally, during a dehumidification request, the stirring ventilation 170 can be deactivated by the regulating unit 160 to limit the evaporation of the condensed water for a given time. This allows the condensed water to flow out of the refrigerated cabinet 100 and reduces the mass of water present in the enclosure (in vapor form and in liquid form).

If the humidification request goes to 1 then the management system S regulates the humidification system 140, for example in particular the fan 104. The humidification of the cabinet 100 is carried out by the passage of air in the water 111. The humidification fan 104 forces the passage of air from the enclosure to the surface of the water in the water tank 111. The air is then charged with moisture and the water evaporates. This water-laden air is then mixed with the ambient air in the refrigerated cabinet 100.

FIG. 5 presents the flowchart for regulating temperature T and absolute humidity HA. When taking a measurement 31 of the sensors 150, the calculation of the absolute humidity HA 32 makes it possible to know the current value of absolute humidity. The measured temperature T is then compared in a step 33, to a set temperature. If the temperature T is not optimal then the regulation on temperature 34 is activated until the temperature T is optimal. For example, the temperature regulation is done when the air is at a temperature located in a hot zone 50 or a cold zone 51. When the temperature T is optimal, that is to say it is between the T1 and T2 values for example, humidity regulation can start.

Zones 52, 53 and 54 are located in the optimal temperature zone. If the temperature T is in the optimal zone, the absolute humidity HA is compared with the value HA_sup + in a step 40. If the value of the absolute humidity HA is greater than the value HA_sup +, then the system goes into dehumidification 41. This is equivalent to saying that the ambient air of the enclosure is at temperature and humidity conditions corresponding to the dehumidification zone 52. If the temperature increases or decreases and goes outside the high T2 and low T1 limits then the system regulates the temperature again.

If in step 40 the absolute humidity HA is not greater than HA_sup +, in a new step 42, the absolute humidity HA is compared with the value HAsup. If HA is greater than HA sup, the process continues the measurements from step 31. If HA is not greater than HA sup, the dehumidification request is zeroed in step 43, then HA is compared to HAinf in step 44. If HA is greater than HAinf, the humidification request is zeroed in step 45. If HA is not greater than HAinf, HA is compared to HAinf- in step 46. If in step 46 it is detected that the absolute humidity value HA drops below the value HA then the system must initiate a humidification step 47. The temperature and humidity conditions correspond to the humidification climatic zone 53. To switch on the humidifier 140, the refrigeration system must be deactivated. Indeed, if this is activated, then the evaporator of the refrigeration system is cooled to a temperature below the dew temperature to condense the water present in the air of the refrigerated cabinet.

The addition of humidity at this time does not humidify the cabinet but increases condensation. This water can even frost and affect the efficiency of the heat exchange between the evaporator and the air in the refrigerated cabinet 100. It is therefore unwise to humidify the air when the refrigeration system is switched on. Thus, if the refrigeration system is deactivated, the humidification system 140 can therefore be activated.

If the temperature and humidity conditions correspond to the neutral zone 54 then the temperature and humidity are ideal. The neutral zone 54 is defined by the high humidity value HA sup 9 and low HA inf 6, respectively identified in FIG. 6 by bodies of water M2 and M1.

The regulation of the actuators of the refrigerated cabinet 100 as well as the humidification system 140 allow a great autonomy and a total management of the humidity whatever the climatic conditions outside the refrigerated enclosure.

As an alternative to using the absolute humidity value HA, the regulation can also use the dew temperature, or any other parameter coupling the temperature value to the relative humidity value for the humidity regulation of the ambient air of the enclosure. The dew temperature can be calculated from temperature and relative humidity, or measured by a sensor. This taking into account the coupling with the ambient air temperature of the refrigerated enclosure allows better accuracy by avoiding inaccuracies due to variations in relative humidity.

Claims (10)

1. System (S) for managing the humidity of the ambient air of a refrigerated enclosure (100) of low volume, comprising: - a refrigeration system controlling the temperature of the ambient air in the refrigerated enclosure, - a humidification system (140) of the ambient air of the refrigerated enclosure, - a humidity measurement system (150), - a regulation unit (160) controlling the refrigeration system and the humidification system as a function of data recorded by the humidity measurement system so as to humidify or dehumidify the ambient air of the refrigerated enclosure. 2. Humidity management system according to claim 1, characterized in that the humidification system (140) comprises a water tank (111) and a ventilation system (104) forcing the passage of air in the water tank (111). 3. Humidity management system according to one of the preceding claims, characterized in that the refrigeration system is used for cooling and for dehumidifying the ambient air of the refrigerated enclosure (100). 4. Humidity management system according to one of the preceding claims, characterized in that it also comprises a stirring system (170) of the ambient air internal to the cabinet, controlled by the regulating unit (160) so that it can be deactivated. 5. Refrigerated enclosure (100) of low volume, such as a refrigerated cabinet for the conservation of wines, comprising a management system (S) according to one of the preceding claims. 6. Method for regulating the humidity of the ambient air of a refrigerated enclosure (100) of small volume, characterized in that it uses, for regulating the humidity of the ambient air of the enclosure , the absolute humidity value, or the dew temperature, or another parameter coupling the temperature value to the relative humidity value. 7. A method of regulating humidity according to claim 6, characterized in that it implements a regulation system (S) comprising a refrigeration system, a humidification system (140) of the ambient air of the refrigerated enclosure, a temperature and humidity measurement system (150), and a regulation unit (160) controlling the refrigeration system, and the humidification system according to data recorded by the temperature measurement system and humidity (150), and in that it comprises steps consisting in: - a) initiating a dehumidification step (12) when a humidity value exceeds a higher threshold value (11), until the humidity decreases below a value (9) lower than the threshold value greater (11) and greater than or equal to a set value (7); b) initiate a humidification step (4) when a humidity value becomes less than a lower threshold value (3), until the humidity increases above a value (6) greater than the lower threshold value (3) and less than or equal to the set value (7). 8. A method of regulating humidity according to claim 7, characterized in that in step a), the refrigeration system is activated to dehumidify when the temperature of the ambient air of the refrigerated enclosure is higher than a temperature setpoint. 9. A method of regulating humidity according to one of claims 7 and 8, characterized in that in step b), the humidification system (140) is activated when the refrigeration system is not engaged. 10. A method of regulating humidity according to one of claims 7 to 9, characterized in that the regulation system (S) comprises a stirring system (170), and in that in step a), the stirring system (170) is deactivated to dehumidify.