A COOLING DEVICE COMPRISING A THAWING COMPARTMENT AND THE CONTROL METHOD THEREOF

Abstract

The present invention relates to a cooling device comprising a body; a thawing body that is disposed in the body, wherein the frozen foods are placed; a heater that heats the thawing compartment and a sensor that provides the measurement of the humidity of the ambient air of the thawing compartment.

Claims

1. A cooling device comprising a body; a thawing body that is disposed in the body, wherein the frozen foods are placed; a heater that heats the thawing compartment and a sensor that provides the measurement of the humidity of the ambient air of the thawing compartment, characterized by a control unit that is disposed on the body, that calculates the humidity level change rate (dH/dt) in the thawing compartment with the data received from the sensor, that enables the thawing process to be started if the calculated humidity level change rage (dH/dt) is above the humidity level decrease rate limit value (V1) determined by the manufacturer or that enables the thawing process to be ended if the calculated humidity level change rate (dH/dt) is between the humidity level increase rate lower limit value (Vbot) determined by the manufacturer and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer.

2. A cooling device as in claim 1, characterized by the control unit that enables the thawing compartment cover to be kept locked from the start of the thawing process until the end of the thawing process.

3. A cooling device as in claim 1, characterized by the control unit that decides that the thawing compartment cover is opened if the humidity level change rate (dH/dt) inside the thawing compartment exceeds the humidity level increase rate upper limit value (Vtop) determined by the manufacturer during the thawing process and that enables the user to be informed that the thawing process has not ended.

4. A cooling device as in claim 1, characterized by the control unit that enables the user to be warned audibly and/or visually that the thawing process is completed at the end of the thawing process.

5. A cooling device as in claim 1, characterized by the control unit that enables the delivery of cool air into the thawing compartment if the thawing compartment cover is not opened for a time determined by the manufacturer after the completion of the thawing process.

6. A control method for a cooling device as in claim 1, executed by the control unit and characterized by the step of calculating the humidity level change rate (dH/dt) inside the thawing compartment.

7. A control method as in claim 6 for a cooling device as in claim 1, executed by the control unit and comprising the steps of comparing the humidity level change rate (dH/dt) with the humidity level decrease rate limit value (V1) determined by the manufacturer and starting the thawing process upon deciding that a frozen food is placed into the thawing compartment if the humidity level change rate (dH/dt) is above the humidity level decrease rate limit value (V1) determined by the manufacturer.

8. A control method as in claim 6 for a cooling device as in claim 1, executed by the control unit and comprising the steps of controlling if the humidity level change rate (dH/dt) is between the humidity level increase rate lower limit value (Vbot) determined by the manufacturer and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer after the thawing process started and ending the thawing process upon deciding that the thawing process is completed if the humidity level change rate (dH/dt) is between the humidity level increase rate lower limit value (Vbot) determined by the manufacturer and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer.

Description

[0014] The cooling device realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0015] FIG. 1—is the perspective view of the cooling device having a thawing compartment.

[0016] The elements illustrated in the figures are numbered as follows:

[0017] 1. Cooling device

[0018] 2. Body

[0019] 3. Thawing compartment

[0020] 4. Heater

[0021] 5. Sensor

[0022] 6. Control unit

[0023] The following symbols are used in explicating the cooling device (1) of the present invention:

[0024] dH/dt : Humidity level change rate

[0025] V1 : Humidity level decrease rate limit value determined by the manufacturer

[0026] Vbot : Humidity level increase rate lower limit value determined by the manufacturer

[0027] Vtop : Humidity level increase rate upper limit value determined by the manufacturer

[0028] The cooling device (1) comprises a body (2); a thawing body (3) that is disposed in the body (2), wherein the frozen foods are placed; a heater (4) that heats the thawing compartment (3) and a sensor (5) that provides the measurement of the humidity of the ambient air of the thawing compartment (3).

[0029] By heating the interior of the thawing compartment (3) by means of the heater (4), the frozen foods are thawed. The thawing process is realized at lower temperatures, for example at 10-15 C degrees for health reasons. By means of the thawing process realized at low temperatures, while the frozen foods are being thawed, the growth of bacteria is slowed (FIG. 1).

[0030] The cooling device (1) of the present invention comprises a control unit (6) that is disposed on the body (2), that calculates the humidity level change rate (dH/dt) in the thawing compartment (3) with the data received from the sensor (5), that enables the thawing process to be started if the calculated humidity level change rage (dH/dt) is above the humidity level decrease rate limit value (V1) determined by the manufacturer or that enables the thawing process to be ended after the thawing process is started if the calculated humidity level change rate (dH/dt) is between the humidity level increase rate lower limit value (Vbot) determined by the manufacturer and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer. By means of this embodiment, the thawing process is started and ended independently from the physical properties of the frozen food, such as shape, weight, etc.

[0031] When frozen food is placed into the thawing compartment (3), condensation occurs on the frozen food that is colder than the ambient air in the thawing compartment (3). As the water vapor inside the thawing compartment (3) condenses on the frozen food, the humidity level in the air decreases. Since the humidity level inside the thawing process (3) is not the same for each cycle, the control unit (6) controls the humidity level change rate (dH/dt). In other words, the thawing process is controlled according to the change trends for different humidity levels for different conditions. If the humidity level change rate (dH/dt) is above the humidity level decrease rate limit value (V1) determined by the manufacturer as a result of experiments conducted under different conditions, in other words if the humidity level decreases faster than the limit value, the control unit (6) decides that a frozen food is placed into the thawing compartment (3) and starts the thawing process. The thawing process starts as the control unit (6) starts the heater (4). By means of this embodiment, the user is not required to press an activation button and the quality perception of the user is improved.

[0032] The heat transferred to the frozen food in the thawing process is used for melting the water that is in solid phase on the food. Since the heat dissipates from the surface towards the center thereof, the ice on the surface of the food melts before the ice at the center thereof. In this case, water is present on the frozen food in both solid and liquid phases. Since the latent heat of melting of ice is much lower than the latent heat of vaporization of water, the heat transferred to the frozen food is first used mostly for melting the ice. For this reason and moreover since the ambient temperature is low during the thawing process, the thawing process is realized almost isothermally, in other words without the melting of all the ice on the frozen food, the melted water does not start to vaporize. Since the thawing compartment (3) is a closed volume without any air intake/exit, the humidity level does not increase before the condensed water and the melted ice do not evaporate. For this reason, the humidity level inside the thawing compartment (3) does not increase before the frozen food is not entirely thawed. After the frozen food is fully thawed, the heat transferred to the frozen food by the heater (4) enables the water on the food to evaporate and increases the humidity level inside the thawing compartment (3). The control unit (6) compares the humidity level change rate (dH/dt) with the humidity level increase level lower limit value (Vbot) and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer as a result of experiments conducted under different conditions and if the humidity level change rate (dH/dt) is between these limit values (Vbot, Vtop), decides that the ice on the frozen food has entirely melted and ends the thawing process. When the thawing process is ended, the control unit (6) deactivates the heater (4).

[0033] In an embodiment of the present invention, the control unit (6) enables the thawing compartment (3) cover to be kept locked after the start of the thawing process and until the thawing process is ended. By keeping the thawing compartment (3) cover locked during the thawing process, the heat losses are minimized and the thawing process is prevented from being prolonged.

[0034] In another embodiment of the present invention, the control unit (6) decides that the thawing compartment cover is opened if the humidity level change rate (dH/dt) inside the thawing compartment (3) exceeds the humidity level increase rate upper limit value (Vtop) determined by the manufacturer during the thawing process and enables the user to be informed that the thawing process has not ended. When the thawing compartment (3) cover is opened during the thawing process, the humid air in the outer environment causes the humidity level inside the thawing compartment (3) to rise quickly. The rate of the said increase is above the humidity level increase rate upper limit value (Vtop) determined by the manufacturer as a result of the experiments under different conditions. Thus, by monitoring the humidity level change rate (dH/dt) inside the thawing compartment (3), the control unit (6) detects if the thawing compartment (3) cover is opened or not.

[0035] In another embodiment of the present invention, the control unit (6) enables the user to be warned by audio or visual means that the thawing process has ended when the thawing process is completed. The control unit (6) conveys the information to the user that the food is thawed and ready for use when the thawing process is completed.

[0036] In another embodiment of the present invention, the control unit (6) enables the delivery of cool air into the thawing compartment (3) if the thawing compartment (3) cover is not opened for a time determined by the manufacturer after the completion of the thawing process. When the thawing process is completed and if the user does not open the thawing compartment (3) cover for a predetermined time, the control unit (6) provides the delivery of cool air into the thawing compartment so that the present heat inside the thawing compartment (3) does not dry/cook the thawed food. Thus, the thawed food does not lose any excess water.

[0037] In another embodiment of the present invention, the thawing compartment (3) comprises at least one fan (not shown in the figures) that enables the air therein to be propelled. By means of the fan, the air inside the thawing compartment (3) is circulated and the heat and the humidity are enabled to be homogeneously distributed.

[0038] In the cooling device (1) of the present invention, the thawing process is controlled by means of a control method executed by the control unit (6) and comprising the step of [0039] calculating the humidity level change rate (dH/dt) inside the thawing compartment (3).

[0040] In another embodiment of the present invention, in the control method executed by the control unit (6), the thawing process is controllably started by means of the steps of [0041] comparing the humidity level change rate (dH/dt) with the humidity level decrease rate limit value (V1) determined by the manufacturer and [0042] starting the thawing process upon deciding that a frozen food is placed into the thawing compartment (3) if the humidity level change rate (dH/dt) is above the humidity level decrease rate limit value (V1) determined by the manufacturer.

[0043] In another embodiment of the present invention, in the control method executed by the control unit (6), the thawing process is controllably ended by means of the steps of [0044] controlling if the humidity level change rate (dH/dt) is between the humidity level increase rate lower limit value (Vbot) determined by the manufacturer and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer after the thawing process started and [0045] ending the thawing process upon deciding that the thawing process is completed if the humidity level change rate (dH/dt) is between the humidity level increase rate lower limit value (Vbot) determined by the manufacturer and the humidity level increase rate upper limit value (Vtop) determined by the manufacturer.

[0046] In the cooling device (1) of the present invention, the thawing process is started or ended independently from the weight and temperature of the food according to the humidity level change rate (dH/dt) inside the thawing compartment (3). Ending the thawing process at the right time, the control unit (6) prevents the food from semi-thawing or from being boiled/roasted by overheating.