Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
  • F25D17/04—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection
  • F25D17/042—Air treating means within refrigerated spaces
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D29/00—Arrangement or mounting of control or safety devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2600/00—Control issues
  • F25B2600/02—Compressor control
  • F25B2600/025—Compressor control by controlling speed
  • F25B2600/0251—Compressor control by controlling speed with on-off operation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2600/00—Control issues
  • F25B2600/11—Fan speed control
  • F25B2600/112—Fan speed control of evaporator fans
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/02—Humidity
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
  • F25D17/04—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection
  • F25D17/06—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection by forced circulation
  • F25D17/062—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection by forced circulation in household refrigerators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D2317/00—Details or arrangements for circulating cooling fluids; Details or arrangements for circulating gas, e.g. air, within refrigerated spaces, not provided for in other groups of this subclass
  • F25D2317/04—Treating air flowing to refrigeration compartments
  • F25D2317/041—Treating air flowing to refrigeration compartments by purification
  • F25D2317/0411—Treating air flowing to refrigeration compartments by purification by dehumidification
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D2400/00—General features of, or devices for refrigerators, cold rooms, ice-boxes, or for cooling or freezing apparatus not covered by any other subclass
  • F25D2400/04—Refrigerators with a horizontal mullion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D2700/00—Means for sensing or measuring; Sensors therefor
  • F25D2700/12—Sensors measuring the inside temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D2700/00—Means for sensing or measuring; Sensors therefor
  • F25D2700/14—Sensors measuring the temperature outside the refrigerator or freezer

Definitions

• the present invention relates to a no-frost refrigerator and an operating method for such a device.
• an evaporator is arranged in a chamber separated from a storage compartment for refrigerated goods, and heat is exchanged between the chamber and the storage compartment, through which the storage compartment is cooled, by cooling and drying air into the storage compartment using a fan on the evaporator blown and relatively warm, humid air is drawn into the chamber from the storage compartment.
• the storage compartment is not only cooled, but also dehumidified.
• the moisture condenses on the evaporator.
• This dehumidification prevents condensation on the storage shelves and refrigerated goods from being deposited under critical climatic conditions, especially when using the refrigerator in a warm environment with high air humidity.
• this advantage can turn into a disadvantage in less critical environmental conditions if stored food is dried out by the intensive dehumidification.
• the circulation capacity of the fan of such a refrigeration device By varying the circulation capacity of the fan of such a refrigeration device, the heat flow between the two at a given temperature difference between the storage compartment of the refrigeration device and the evaporator is also changed. This means that a reduction in the circulation capacity leads to a reduced heat exchange and thus to a greater cooling of the evaporator. This increased cooling results in more intensive drying of the air flowing past the evaporator.
• the reduced circulation capacity means that when the evaporator and fan are switched on, the cooling of the storage compartment is slower takes place than with a higher circulation capacity, so that the duty cycle of the evaporator is extended. This extension compensates for the reduced circulation capacity and leads to the fact that more moisture is trapped in the course of a switch-on phase of the evaporator with a low circulation capacity than with a high one.
• a variable circulation capacity of the evaporator can be realized in a simple manner by making the fan temporarily switchable in the switched-on phase of the evaporator.
• a control circuit for controlling the operation of the evaporator and the fan is provided, which is set up to operate the fan intermittently when the evaporator is switched on and thereby throttle its average circulation capacity compared to a continuous operation.
• a selector switch can be provided on the refrigeration device, which enables a user to set a desired duty cycle for the intermittent operation of the fan and thus to manually adjust the drying effect of the refrigeration device to the need.
• the control circuit is connected to at least one climate sensor for detecting a climate parameter such as that
• the fan can be set to different non-disappearing speeds in the switched-on phase of the evaporator in order to adapt the mean circulation capacity to the demand.
• a selector switch can be provided, which allows a user to specify a desired speed of rotation of a fan control circuit, or the control circuit can be coupled to at least one climate sensor in order to determine the circulation capacity of the fan on the basis of a climate parameter detected by this sensor and a predefined one Automatically control target humidity.
• the invention also relates to a method for operating a refrigeration device of the type described above, comprising the steps:
• the estimate is preferably a humidity measurement carried out directly in the storage compartment concerned. Then it is possible in particular to take into account the influences of the operation of the evaporator and the fan on the air humidity in the storage compartment when selecting the circulation capacity. In principle, however, it is also possible to estimate the air humidity in the storage compartment on the basis of variables correlated with it, such as the temperature and air humidity of the environment, and to select the circulating capacity depending on the result of the estimation.
• FIG. 1 shows a schematic illustration of a no-frost refrigerator according to the invention
• Figure 2 is a timing diagram of the operation of the evaporator and fan according to a first embodiment of the invention.
• Figure 3 is a timing diagram analogous to that of Figure 2 for a second embodiment of the invention.
• FIG. 1 is a schematic representation of a combination refrigerator, on which the present invention is implemented.
• a refrigerator compartment 1 and a freezer compartment 2 form two temperature zones of the refrigerator.
• a refrigerant circuit comprises a compressor 3, which pumps a compressed refrigerant one after the other through two evaporators 4, 5 of the freezer compartment 2 or the refrigerator compartment 1, and a heat exchanger 6 through which the refrigerant expanded in the evaporators 4, 5 passes before it returns to the Compressor 3 occurs.
• the evaporator 5 assigned to the cooling compartment 1 is accommodated in a chamber 8 separated from the cooling compartment 1 by a thermally insulating wall 7.
• the chamber 8 communicates with the cooling compartment 1 via air inlet and outlet openings, a fan 9 for forcibly circulating air being arranged between the chamber 8 and the cooling compartment 1 in one of these.
• a control circuit 10 is connected to a temperature sensor 12 arranged in the refrigerator compartment and via control lines to the compressor 3 and the fan 9 and is able to control the compressor 3 and the fan 9 - and indirectly via the compressor 3 the evaporators 4, 5 - in Depending on a temperature detected by the temperature sensor 12 on or off.
• the control circuit 10 is also connected to an air humidity sensor 13 which is arranged in the cooling compartment 1.
• a control switch 10, which can be operated by a user and which allows a target value for the air humidity in the cooling compartment 1 to be set, can be provided on the control circuit 10.
• the air humidity sensor 13 in the cooling compartment 1 can also be replaced as a variant by an air humidity sensor outside the cooling compartment and / or a sensor for the ambient temperature of the refrigerator, since their measured values allow conclusions to be drawn about the air humidity in the cooling compartment 1.
• FIG. 2 illustrates the mode of operation of the control circuit 10 on the basis of the time profiles of a plurality of operating parameters of the refrigeration device.
• the curve 3 ' indicates the operating state of the compressor 3. At time t 0 it is switched off; as soon as the temperature sensor 12 registers that an upper limit temperature has been exceeded, at time ti, it is switched on until time t 2 falls below a lower limit temperature in the cooling compartment 1. From this time, the cooling compartment 1 heats up again until a new start-up phase of the compressor 3 begins at t.
• the humidity detected by the sensor 13 in the cooling compartment 1 is at a constant, low level.
• the fan 9 also starts at the time ti, as shown by a curve 9 '.
• the temperature of the evaporator 5, represented by a curve 5 ' decreases from a rest value T 0 to a value 1 ⁇ .
• Moisture from the air circulated by the fan 9 condenses on the evaporator 5, so that the air humidity 13 'slowly decreases until the time t 2 when the fan 9 is switched off. From the time t 3 , the moisture 13 'rises sharply, for example because the door of the refrigeration device is opened and warm, moist air penetrates from the outside.
• the control circuit 10 recognizes that more intensive drying is required and operates the fan 9 when the compressor 3 is switched on again at the time t 4 , intermittently with a pulse duty factor which is selected as a function of the atmospheric humidity recorded at the time t 4 .
• the switch-on period t 4 to t 5 is therefore longer than the period ⁇ to t 2 , and the temperature T 2 of the evaporator 5 reached during this period is lower than Ti. This lower temperature T 2 leads to the air flowing past the evaporator 5 is dried more effectively, and due to the increased duty cycle of the compressor 3, a low air humidity value is finally reached again.
• the duty cycle with which the control circuit 10 operates the fan during the switch-on phases of the evaporator is, in the simplest case, a step function which has the value 1 for low atmospheric humidities and a non-vanishing value less than 1 for high atmospheric humidities; it is also possible to use a step function with a large number of duty cycle values that decrease with increasing humidity or a continuous function for control purposes.
• the control circuit 10 is designed to set different speeds of the fan 9 as a function of a measured air humidity.
• the operation of this embodiment is shown in Figure 3. If the air humidity is low, the fan 9 runs at maximum speed in a switch-on phase of the evaporator 4, and the chronological courses of the switch-on and switch-off phases, evaporator temperature and air humidity are the same as in the case of FIG. 2. As a result, the diagram of the figure differs 3 up to time t not from that of FIG. 2. At time t, the control circuit 10 uses the high humidity value measured at this time to select a speed of the fan 9 which is less than its maximum speed.
• the air humidity decreases continuously, and accordingly the speed of the fan 9, which the control circuit 10 selects on the basis of the measured air humidity, and with increasing circulation capacity of the fan 9, the temperature of the evaporator 5 also rises to a high level Part of the time interval t 4 to t 5 continuously.
• FIGS. 2 and 3 show the case of rapid drying out, in which a single switch-on phase t to t 5 is sufficient to reduce the air humidity in the cooling compartment Target value.
• the drying process can also be spread over several successive switch-on phases.
• the maximum circulation capacity of the fan 9 corresponds in each case to a desired low air humidity value in the cooling compartment, so that increased drying can be achieved by throttling the circulation capacity.
• Temperature of the evaporator 5 whose drying effect is weakened. This also makes it possible to specifically increase the humidity in the cooling compartment 1 if it drops below a desired value.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Cold Air Circulating Systems And Constructional Details In Refrigerators (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)
• Air Conditioning Control Device (AREA)
• Drying Of Solid Materials (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=33482794

Family Applications (1)

Country Status (5)

Cited By (5)

Families Citing this family (20)

Citations (17)

Family Cites Families (13)

• 2003
  • 2003-06-11 DE DE20321771U patent/DE20321771U1/de not_active Expired - Lifetime
  • 2003-06-11 DE DE10326329A patent/DE10326329A1/de not_active Withdrawn
• 2004
  • 2004-06-09 EP EP04739760.9A patent/EP1636530B1/de not_active Expired - Lifetime
  • 2004-06-09 CN CN2010102435067A patent/CN101893363A/zh active Pending
  • 2004-06-09 US US10/560,156 patent/US20070137227A1/en not_active Abandoned
  • 2004-06-09 CN CNA2004800163592A patent/CN1806155A/zh active Pending
  • 2004-06-09 WO PCT/EP2004/006256 patent/WO2004109205A1/de active Application Filing

Patent Citations (17)

Non-Patent Citations (2)

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