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
  • F25B21/00—Machines, plants or systems, using electric or magnetic effects
  • F25B21/02—Machines, plants or systems, using electric or magnetic effects using Peltier effect; using Nernst-Ettinghausen effect
• • 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
  • F25B2321/00—Details of machines, plants or systems, using electric or magnetic effects
  • F25B2321/02—Details of machines, plants or systems, using electric or magnetic effects using Peltier effects; using Nernst-Ettinghausen effects
  • F25B2321/021—Control thereof
  • F25B2321/0212—Control thereof of electric power, current or voltage
• • 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
  • F25B2321/00—Details of machines, plants or systems, using electric or magnetic effects
  • F25B2321/02—Details of machines, plants or systems, using electric or magnetic effects using Peltier effects; using Nernst-Ettinghausen effects
  • F25B2321/023—Mounting details thereof

Definitions

• the present invention relates to a cooling unit for a refrigerator, in particular a small refrigerator.
• the object of the invention is to provide a cooling unit of the type mentioned, which has no moving parts, is completely maintenance-free, has a long service life, consumes only relatively little electrical energy for its operation and has no switch-on power peaks.
• thermoelectric Peltier element is present as the cooling source, which is on the one hand in a heat-conducting connection with a first heat exchanger to be arranged in the interior of the refrigerator and on the other hand with a second heat exchanger to be arranged on an outer wall of the refrigerator, in such a way that electrical energy is supplied In the feed circuit of the Peletier element, heat is transported from the first to the second heat exchanger.
• An electrical circuit arrangement is provided for regulating the supply of electrical energy to the feed circuit of the Peltier element.
• FIG. 1 shows a horizontal section along the line 1 - 1 in FIG. 2 through part of a refrigerator and a top view of a cooling unit according to the invention fitted to the refrigerator;
• FIG. 2 shows a cross section along the line 2-2 in Figure 1, on a larger scale.
• Fig. 3 shows an electrical circuit arrangement for automatically regulating the energy supply to the thermoelectric Peltier element of the cooling unit.
• a refrigerator 10 has a rear wall 11 and two side walls 12 and 13 which project beyond the rear wall 11 to the rear.
• the inner surfaces of the refrigerator 10 are covered with an insulating layer 14.
• At this heat-conducting block 15 is by means of screws 17 on the Arranged rear of the refrigerator arranged metal block 18, with the interposition of a thermoelectric Peltier element 19 which is clamped by means of screws 17 between the two metal blocks 15 and 18.
• the Peltier element 19 is a commercially available example, which is supplied, for example, by the North American company Melcor under the type designation 1.4 / 127.06L.
• Peltier element is constructed in a sandwich-like manner and has two pairs of semiconductor organs between two heat-conducting but electrically insulating end plates, which are in heat-conducting contact with the two blocks 15 and 18, which are electrically connected in series internally and the supply circuit of the Form the Peltier element. Since such Peltier elements are commercially available as mentioned, a detailed description and graphic representation can be dispensed with here.
• the metal block 20 has a bore 22 in which an end part of a so-called heat pipe 23 is seated, which is otherwise provided with a larger number of convection fins 24.
• the heat pipe 23 consists, in a known manner, of an evacuated copper pipe which is closed at both ends and filled with saturated steam of high-purity water and on its cylindrical inner surfaces with a covering 25 acting as a wick (FIG. 2) is provided. Heat pipes of this type are also commercially available and are manufactured, for example, by Furuka a Electric Co. Ltd., Tokyo (Japan) and are marketed under the type designation SB 100.
• the metal block 20, the heat pipe 23 and the fins 24 together form a first heat exchanger, which is arranged in the interior of the refrigerator 10.
• the already mentioned metal block 18 on the rear of the refrigerator 10 has two parallel bores 26 and 27, in each of which an end part of a heat pipe 28 and 29 is seated. These two heat pipes 28 and 29 are of the same design as the previously described heat pipe 23 and are also each provided with a larger number of convection fins 30 and 31, respectively.
• the metal block 18 and the heat pipes 28 and 29 with their fins 30 and 31 together form a second heat exchanger, which is located on the outside of the rear wall 11 of the refrigerator.
• a housing 33 is fastened by means of screws 32 (FIG. 2), which contains an electrical circuit arrangement for automatically regulating the supply of electrical energy to the feed circuit of the Peltier element 19 already mentioned.
• the electrical circuit arrangement 34 has an electronic voltage comparator 35 with two inputs 36 and 37 and an output 38.
• a constant reference voltage Ui is applied to the positive input 36, generated by means of a bridge rectifier 39, smoothed by two capacitors 40, 41 and a resistor 42, stabilized to a constant value Uo by means of a voltage stabilizer 43 and by means of a voltage divider 44, 45 is reduced to the desired value Ui.
• the bridge rectifier 39 has two connection terminals 46 and 47, which are to be connected to the AC network via a transformer (not shown).
• a second voltage divider 48, 49 which reduces the stabilized voltage Uo to a variable value U2.
• This second voltage divider consists of an adjustable fixed resistor 48 and a variable resistor 49, which has a pronounced negative temperature coefficient (NTC) and serves as a temperature sensor.
• NTC negative temperature coefficient
• the heat-conducting block 15 is provided with a bore 50 for receiving the variable resistor 49, which is connected to two connection terminals 51, 52 of the circuit arrangement 34.
• a capacitor 53 is used to suppress short-term fluctuations in the variable voltage U2.
• the output 38 of the voltage comparator 35 is via a Protective resistor 54 is connected to the control input 55 of an electronic FET switch 56, which is looped into the feed circuit of the Peltier element 19.
• the circuit arrangement 34 has two terminals 57 and 58 for connecting the Peltiei element 19. When the switch 56 is turned on, the Peltier element 19 is supplied directly with the unstabilized voltage from the bridge rectifier 39.
• variable resistor 49 serving as a temperature sensor becomes smaller, which results in a corresponding decrease in the variable voltage U2 at the negative input 37 of the voltage comparator 35. If the variable voltage U2 falls below the value of the reference voltage Ui, that at the control input 55 of the electronic switch 56 lying voltage U3 suddenly almost zero. As a result, the switch 56 is controlled in its non-conductive or blocking state and thus the supply circuit of the Peltier element 19 is interrupted. The cooling unit is then in an inactive state, which is indicated visually by the LED 59 going out.
• the cooling capacity of the cooling unit is in the range from 5 to 30 watts, depending on the temperature difference between the two heat exchangers, inside and outside. With an appropriate setting of the adjustable resistor 48, it is possible to lower the temperature inside the refrigerator to about 20 ° C. if the outside temperature is in the range of the usual living room temperature.
• the cooling unit described does not require any maintenance and has an extremely long lifespan in the order of 150 * 000 hours or more.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)
• Pyrane Compounds (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Air-Conditioning For Vehicles (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4177625

Family Applications (1)

Country Status (11)

Cited By (1)

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Citations (14)

Family Cites Families (1)

• 1988
  • 1988-01-05 CH CH23/88A patent/CH675154A5/de not_active IP Right Cessation
  • 1988-12-27 JP JP1500282A patent/JPH02502846A/ja active Pending
  • 1988-12-27 AT AT89900179T patent/ATE83309T1/de not_active IP Right Cessation
  • 1988-12-27 AU AU27976/89A patent/AU627705B2/en not_active Ceased
  • 1988-12-27 EP EP89900179A patent/EP0350502B1/de not_active Expired - Lifetime
  • 1988-12-27 WO PCT/CH1988/000228 patent/WO1989006335A1/de active IP Right Grant
  • 1988-12-27 DE DE8989900179T patent/DE3876621D1/de not_active Expired - Fee Related
  • 1988-12-27 BR BR888807399A patent/BR8807399A/pt unknown
• 1989
  • 1989-08-29 FI FI894038A patent/FI894038A0/fi not_active Application Discontinuation
  • 1989-09-04 NO NO893534A patent/NO170743C/no unknown
  • 1989-09-04 DK DK437089A patent/DK437089D0/da not_active Application Discontinuation

Patent Citations (14)

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