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
  • 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
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D11/00—Self-contained movable devices, e.g. domestic refrigerators
  • F25D11/006—Self-contained movable devices, e.g. domestic refrigerators with cold storage accumulators
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D23/00—Control of temperature
  • G05D23/19—Control of temperature characterised by the use of electric means
  • G05D23/1919—Control of temperature characterised by the use of electric means characterised by the type of controller
  • G05D23/1921—Control of temperature characterised by the use of electric means characterised by the type of controller using a thermal motor
• • 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
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/15—Power, e.g. by voltage or current
• • 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
  • F25B2700/21—Temperatures
  • F25B2700/2117—Temperatures of an evaporator
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B40/00—Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Definitions

• the present invention generally relates to refrigeration apparatus, and more particularly the invention is concerned with an energy poor refrigeration apparatus having control means for utilizing as best as possible the energy received by refrigeration apparatus.
• the invention is useful for practically any types of electrically driven refrigeration apparatus, but it is of best importance for battery driven refrigerators, and in the following the invention will mainly be described in connection to refrigeration apparatus driven by rechargeable accumulator batteries, especially 12 volt or 24 volt batteries. It is, however, to be understood that the invention is not restricted to this type of driving means and that the invention can also be used for mains-operated refrigeration apparatus.
• refrigeration apparatus For reducing the energy consumption different attempts have been made to reduce the current consumption of the electric apparatus.
• refrigeration apparatus provide special problems since the refri eration needs often exceed the avaliable electric capacity.
• the problems may partly be solved in that larger effects are used for the refrigeration apparatus when the supply of current is good, that is when the motor is running, than when the motor is not running.
• By lowering the temperature of the fridge or the cooling box to a level above the normal cooling level some stored cooling capacity is obtained, and therefore the cooling type of the fridge or the box is prolounged.
• some refrigeration apparatus have been formed with a so called eutectic cooler plate which is mounted in the fridge or the cooling box instead of the conventional cooler slings.
• the eutectic cooler plate is a closed body containing a spirit or salt solution having a very low freezing temperature, for instance -15 to -20°C.
• the invention relates to a refrigeration apparatus of the above mentioned type, which as conventional comprises a compressor having a condensor and a pri ery cooler but which comprises a eutectic cooler plate adapted to be mounted in the fridge or the cooling box instead of cooler slings.
• the special novelty of the invention is a particular control device which senses the voltage over the battery pools thereby also checking if the motor is running or not, and which depending thereon charges the eutectic cooler plate to different cooler capacities if the motor is running or is not running respectively. More particularly the control device choses two different cooling levels, viz. a low cooling level util zed if the motor s not running and high cooling level if the motor is running.
• the control device operates based on the fact that the voltage over the battery pools at charge condition is higher than a specific voltage level whereas the voltage over the battery pools at non-charge state is on a lower voltage level.
• the cooling compressor is operated until the cooling medium of the eutectic plate has completely or partly become frozen to ice, for instance a temperature of between -8°C and -15°C, in the latter case the cooling compressor is operated only until the still liquid medium of the eutectic cooler plate has obtained a temperature of for instance -2°C and -6°C.
• figure 1 diagra atically shows a system according to the invention including a compressor driven refrigeration apparatus having a eutective cooler plate.
• Figure 2 is a block diagram over an electronic control device for the compressor driven refrigeration apparatus.
• Figure 3 illustrates a practically noticed operation scheme for a refrigeration apparatus according to the invention.
• the refrigeration apparatus shown in figure 1 comprises a cooling compressor 1 which as usual has a primary condensor or cooler 2 and on the secondary side has a eutective cooler plate 3 mounted on a wall of a cooling box 4.
• a control device 5 for controlling the apparatus, and for utilizing the avaliable electric energy as energy saving as possible the apparatus is formed with a control device 5 according to the invention and a heading unit 6 connected to the control device 5.
• the compressor 1 and the primary condensor or cooler 2 are of conventional type and need not be described in detail.
• the eutectic plate 3 connected on the secondary side of the compressor comprises a closed container which over a closed conduit system 7 is connected to the compressor, and which comprises a cooling medium, for instance a spirit solution, a salt solution, an oil or any similar cool ng medium as known to the expert and which at a certain temperature starts freezing and which at a substantially lower temperature is completely freezed.
• a cooling medium for instance a spirit solution, a salt solution, an oil or any similar cool ng medium as known to the expert and which at a certain temperature starts freezing and which at a substantially lower temperature is completely freezed.
• any known cooling medium may be used, and the cooling medium is adapted to the temperature intended to be reached, to the charging capacity of the motor, to the intended t me of maintaining the chilliness without running the motor and to the intended cooling charge, to the expected ambient temperatures and to the isolation of the fridge or the cooling box and other factures.
• an eutectic cooler plate has been used for the cooling medium of which starts freezing at -8°C and which can be cooled as far as to at least -15°C.
• the compressor is adapted to be driven by an accumulator battery 8 which is charged by a non-illustrated motor having a generator 9 which is connected to the control device 5 for supervising the voltage over the battery pools and thereby checking whether the motor is running (is charging the battery) or not.
• the object of the control system shown in figure 2 is to supply current to the cooling compressor 1 under given prerequisites so that said cooling compressor operates with optimum cooling effect at minimum consumption of energy from the batteries.
• the control unit is to operate on two different cooling levels, viz. a first level between -2 and -6°C, which level is chosen if the voltage over the battery or the batteries indicates that there is no charging of the battery, viz. if the motor is not running, and a second level between -8 and -15°C, which level is chosen if the voltage over the battery pools indicate that the battery or batteries are being charged.
• the pool voltage is at charge voltage or below charge voltage, which for 12 V batteries is put above and below 12,6 V respectively and for 24 V batteries above and below 26,0 V respectively.
• the compressor consequently is connected for operation when the cooling medium temperature of the eutectic cooler plate has raised to -2°C, and it is disconnected when the temperature has dropped to -6°C.
• the apparatus enters this stage when a main switch having connection and disconnection functions of the control device 5 has been.switched on, and the compressor operates interim ' tently and thereby maintains the temperature of the fridge or the cooling box on a suitable cooling level.
• This low cooling level operation goes on until the current is disconnected in that the main switch of the control device 5 is switched of, or until the motor is started and the generator thereof starts charging the battery.
• the electronic control system generally comprises a three way switch 10, a voltage selection system 11 a temperature sensing system 12, an AND-gate system 13, an OR-gate system 14 and means for providing the intended function depending on the state of said gates.
• the positive battery pool is connected to a first main conduit 15 of the control system and the negative battery pool is connected to a second main conduit of the control system.
• the three way switch 10 which is of manual type can take three different position, viz. a neutral position which is marked in figure 2 and at which the entire refrigerator is d sconnected, an automatic function position corresponding to an up-position in figure 2 and in which the compressor is connected and disconnected respectively in accordance with a predetermined voltage l mit, and a positively controlled position corresponding to a down position in figure 2 and in which the compressor is operated independently of the voltage and temperature limits.
• the voltage selection system comprises two comparators 17 and 18 having the voltage 0 or operated with a limit voltage which for a 12 V system may be 5,6 V.
• the said limit voltage is received on a zener diode 19 of 5,6 V.
• the comparator 17 is adapted to emit a signal when the observed pool voltage is ⁇ 12,6 V (12 V system) or ⁇ 26 V (24 V system), and the comparator 18 is adapted to emit a signal when the observed pool voltage is > 12,6 V or > 26 V respectively.
• the temperature sensing system 12 comprises four OP amplifiers (operation amplifiers) 20, 21, 22 and 23. Said OP amplifiers sense voltages of four fixed levels provided by five resistances 24, 25, 26, 27 and 28 connected in series.
• the first resistance 24 is connected between the minus pool 16 and the first OP amplifier 20, the second resistance 25 between the amplifiers 20 and 21, the third resistance 26 between the amplifiers 21 and 22, the fourth resistance 27 between the amplifier 22 and the voltage selection system 11 and the fifth resistance 28 between the voltage selection system 11 and the positive battery conduit 15.
• the OP amplifiers compare said values with a NTC resistance 29 (Negative Temperature Coefficient) which over a conduit 30 is connected to an input of each OP amplifier 20-23.
• the NTC resistance 29 is mounted on the eutectic cooler plate 3 (compare figure 1) and is in direct contact with the centre of said plate.
• a trimming potentiometer 31 is connected in series between NTC resistance 29 and the negative battery conduit 16.
• the four OP amplifiers 20 - 23 are calculated to give signal at suitable connection and disconnection temperatures, and as an exa ple:
• the OP amplifier 20 gives signal at ⁇ -15°C
• the OP amplifier 21 gives signal at > -8°C
• the OP ampl bomb 22 gives signal at ⁇ -6°C
• the OP amplifier 23 gives si nal at > -2°.
• the comparators 17 and 18 of the voltage system 11 and the OP amplifiers 20 - 23 of the temperature system 12 are connected to four OCH-gates 32, 33, 34 and 35 of the type requesting signal at both inputs for giving an output signal.
• Tv/o of the OCH gates 32 and 34 are connected for the voltage condition ⁇ 12,6 V and the two remaining OCH-gates 33 and 35 are connected for the voltage condition > 12,6 V.
• the said two groups of OCH-gates are connected to two OR gates 36, 37 giving signal for the compressor (1 of figure 1) to become connected and disconnected according to the given temperature and voltage conditions.
• This is provided in that the OR gates 36 and 37 are connected to an SR flip-flop 38 (set-reset).
• the SR flip-flop 38 is connected to an OP circuit 39 which amplifies the signal and over a resistance 40 is driving a transistor 41 which is connecting and disconnecting respectively the manerise circuit 42, 43 of the compressor 1.
• the function of the apparatus is the following: When connecting "automatic" of the switch 10 the voltage selection system is connected to voltage and the comparators 17 and 18 observe if the motor is charging or not charging. The state of non-charging which is observed in that the pool voltage of the battery is less than 12,6 V or 26 V respectively the system automatically choses "the low energy alternative", whereby the temperature alternative -2°C to -6°C of the temperature system 12 is connected. This means that the OCH gates 20 and 21 open when the temperature of the eutectic plate 3 has increased to -2°C (according to the selected temperature system) and the compressor 1 starts.
• the eutectic plate 3 has accumulated cooling energy which is sufficient to maintain the chilliness of the fridge or the cooling box for quiet a number of hours, in well isolated cooling boxes and when using a resonably large eutectic cooler plate for a period of 15 - 20 hours.
• the low temperature of -15°C also is sufficient to keep freezed goods in freezed state for many hours.
• the switch 10 is set for positive control, that is the bottom position as shown in figure 2, whereby "the low energy alternative" is over bridged.
• the light emitting diodes 44 and 45 under all conditions indicate the existing state and what type of cold storing that the compressor at the moment is executed and when the system is disconnected respectively.
• the operation scheme shown in figure 3 relates to a compressor driven refrigeration apparatus according to the invention which is driven by an internal combustion engine having a rechargeable accumulator battery.
• At the upper most part I of the scheme is indicated those periods at which the motor is running and consequently the periods when the battery is being charged.
• At the next verthical part II is illustrated how the voltage over the battery pools varies at running and non-running motor respectively and in connection thereto how the comparators 17 and 18 react and are made active.
• part III is illustrated how the cooling medium temperature of the eutectic plate changes when storing cold energy and when utilizing such cold energy during the different operation conditions and in connection thereto how the four OP amplifiers operate.
• At the last part.IV of the scheme is shown those periods when the cooling compressor 1 and the cooling fan are connected and disconnected respectively.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Automation & Control Theory (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)

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• 1984
  • 1984-02-01 SE SE8400514A patent/SE438061B/sv not_active IP Right Cessation
• 1985
  • 1985-01-30 EP EP85900817A patent/EP0169878B2/en not_active Expired - Lifetime
  • 1985-01-30 DE DE8585900817T patent/DE3560499D1/de not_active Expired
  • 1985-01-30 US US06/795,354 patent/US4658593A/en not_active Expired - Lifetime
  • 1985-01-30 WO PCT/SE1985/000043 patent/WO1985003603A1/en active IP Right Grant
  • 1985-01-30 AU AU39338/85A patent/AU581209B2/en not_active Expired

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