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
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B49/00—Arrangement or mounting of control or safety devices
  • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
  • F25B49/022—Compressor control arrangements
• • 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
  • F25B2500/00—Problems to be solved
  • F25B2500/26—Problems to be solved characterised by the startup of the refrigeration cycle
• • 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
  • F25B2600/026—Compressor control by controlling unloaders

Definitions

• the present invention relates to a refrigerator and/or freezer, comprising a liquefier, an evaporator and a compressor.
• the refrigeration circuits of the appliances include an evaporator, in which the refrigerant is evaporated by absorbing heat from the space to be cooled. The evaporated refrigerant then is compressed in the compressor and is then supplied to the liquefier, in which it is liquefied by releasing heat to the surroundings. The refrigerant liquefied in this way is expanded in a throttle means and then again supplied to the evaporator.
• the pressure compensation between the pressure side and the suction side during the downtime of the compressor can for instance be prevented by a shut-off valve between liquefier and evaporator.
• the use of such shut-off valve involves the problem that due to the pressure compensation prevented by the shut-off valve, the compressor must start against a comparatively high pressure in the liquefier.
• the refrigerator and/or freezer has a means for effecting the compressor start-up, wherein the means for effecting the compressor start-up includes one or more of the means mentioned below:
• (v) means for reducing the initially required starting torque.
• the starting torque of the compressor is increased to overcome said pressure difference between the suction side and the pressure side of the compressor.
• This is also meant to include the case that the compressor motor is supported by means which generate a supporting moment, which acts in the direction of the torque applied by the motor.
• These means can for instance be a spring which is tensioned when the compressor is at standstill.
• the means for increasing the starting torque of the compressor comprise at least one spring or elastic element, which is configured and arranged such that it is tensioned in the condition in which the compressor is at standstill and in the tensioned condition exerts a moment supporting the compressor start-up. It is conceivable, for instance, to provide an eccentric moving upon operation of the compressor, which ensures that the spring or the elastic element is tensioned when the compressor is at standstill.
• the compressor motor includes a shaft or that a shaft is connected with the compressor motor, which has at least two separate shaft portions, and that the means for reducing the initially required starting torque comprise a spring or a deformable power transmission element, which is connected with the two separate shaft portions such that a rotation of one shaft portion effects a rotation of the other shaft portion via the spring or the power transmission element.
• the spring or the deformable power transmission element acts as a coupling between the two ends of the shaft portions.
• the spring or the deformable element permits a relative movement (slip) between the two shaft portions, which results in the fact that the initially required starting torque is reduced.
• the spring can be arranged such that it encloses the ends of the shaft portions and furthermore extends in the region between the shaft portions.
• the appliance includes a testing means for checking the starting behavior of the compressor, which is configured such that it detects whether the compressor is starting properly, and that actuating means are provided, which are activated by the means for effecting the compressor start-up with the means (i) and/or (ii) and/or (iv), when it is detected by means of the testing means that the compressor has not started.
• the starting torque of the compressor and/or the starting current of the compressor motor only are increased and/or the at least partial pressure compensation only is performed when it is detected by means of the testing means that the compressor has not started as desired. If this is the case, the starting torque or the starting current can be increased or an at least partial pressure compensation can be performed, in order to provide for a start-up of the compressor.
• the actuating means can form part of the testing means.
• the actuating means are configured such that they are activated by the means for effecting the compressor start-up with the means (i) and/or (ii) and/or (iv) only for a period, until a proper start-up of the compressor is detected by means of the testing means.
• said means must only be activated for a period, until it is detected that the compressor has started. Subsequently, the partial pressure compensation can be prevented e.g. by closing a valve in a bypass line, so that the desired build-up of pressure by the compressor is possible.
• the means for the at least partial pressure compensation between the pressure side and the suction side of the compressor comprise a bypass line, which can be located inside or also outside the compressor housing.
• This bypass line can include a pressure compensation valve.
• a bypass line around the compressor in which a valve is disposed, which is closed in normal operation of the compressor, so that a futile circular flow is prevented, and which is temporarily opened when it is detected that a start-up of the compressor is not possible at back pressure.
• the valve can be opened, which preferably is effected only for such a period and to such an extent until it is detected by means of the testing means that the compressor is running properly.
• a bypass is provided, which connects the pressure side of the compressor with the suction side of the compressor and which likewise leads to the fact that the back pressure is reduced on the pressure side.
• This bypass can of course also include a pressure compensation valve, by means of which an at least partial pressure compensation is possible.
• this pressure compensation valve also is opened for such a period and to such an extent until it is detected by means of the testing means that the compressor now has started properly.
• the refrigerator and/or freezer of the invention includes a compressor, a liquefier provided downstream of the same, and a capillary in which the liquefied refrigerant is expanded. The same then is introduced into the evaporator, whose outlet is connected with the inlet of the compressor.
• an on/off valve is provided, which is located between liquefier and evaporator, preferably in a region between the liquefier and said capillary. While the compressor is at standstill, the valve is closed, which leads to the fact that a comparatively high pressure exists in the liquefier and hence also on the pressure side of the compressor.
• the refrigerator and/or freezer of the invention includes means for increasing the starting torque of the compressor, which are configured such that the starting torque is increased to such an extent that the corresponding pressure difference is overcome and the compressor starts.
• This can also be determined by a suitable testing means.
• actuating means are provided, which effect a corresponding increase of the starting torque. It is conceivable that the actuating means are configured such that they perform an increase of the starting torque stepwise or continuously, until the desired start-up of the compressor is detected by means of the testing means.
• the appliance includes an intelligent electronic starting device, by means of which a safe starting of the compressor should be made possible with the already existing starting torque of the compressor. The same allows to briefly provide a higher starting current than is actually permitted by the motor protection.
• a testing means checks whether the compressor has started, and that the actuating means increase the starting current stepwise or continuously until the start-up of the compressor is detected.
• a testing means checks whether the compressor has started, and if this is not the case, it can for instance be provided that one of the above-mentioned measures and/or also a partial pressure compensation is performed, in order to enable the start-up.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Control Of Positive-Displacement Pumps (AREA)

Applications Claiming Priority (4)

Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (1)

Citations (5)

• 2007
  • 2007-02-16 DE DE202007002352U patent/DE202007002352U1/de not_active Expired - Lifetime
• 2008
  • 2008-01-16 US US12/009,011 patent/US20080196423A1/en not_active Abandoned

Patent Citations (6)

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