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
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
• • 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

Definitions

• This patent describes a new electronic circuit especially developed for refrigeration and air conditioning units devices equipped with thermoelectric semiconductor elements, replacing the traditional systems with a gas compression apparatus, preventing serious environment restrictions and allowing the production of easy and fast assemblage refrigeration devices, more reliable and cheaper than conventional models.
• Refrigeration is the use of technology to transfer heat from a warm body, so that it can remain substantially colder than its surroundings. It is also used to cool and dehumidify air, increasing comfort in such places as homes, offices and vehicles.
• Refrigeration may be produced through the absorption of heat by a gas that has been cooled by an expansion during which external work is performed, as in the air refrigerating machine; through transferring heat from a warmer body to a colder one; by melting and dissolving solid bodies, as in the melting ice, the solutions of salts in water, and in chemical machines; by evaporating liquids that have a relatively low boiling temperature.
• CFC chlorofluorocarbon
• thermoelectric effect This is known as thermoelectric effect.
• thermoelectric refrigerator can be made by placing many junctions in series, separated by plates, so that heat is absorbed on one side and dissipated on the other. On this text, we refer to these special plates as " Peltier cells ".
• thermoelectric refrigerators have so far been limited to a few specialized areas of application because there are not efficient enough.
• the main object of this invention is to provide a thermoelectric refrigeration system equipped with Peltier cells and controlled by a new electronic circuit specifically developed for it, as a result of exhaustive test and laboratory tests.
• the new system may replace the conventional gas compression refrigeration apparatus, has higher efficiency and a lower cost of assemblage and maintenance, providing no movable parts.
• Another object of this invention is to provide a electronic circuit capable to control two or more Peltier cells simultaneously, disposed in series or in parallel connection, allowing to obtain higher refrigeration power devices.
• Another object of the same invention is to provide a electronic circuit that allows a narrow optimized control helping to get an accurate system of temperature adjustments.
• the Peltier cell necessarily should operate within a given voltage range. If higher voltages are provided, greater amount of power will be required and smaller increases of refrigeration are achieved, decreasing the overall system efficiency and providing the cells overheating.
• thermoelectric cells should be controlled by a Pulse With Modulation ( PWM ) circuit, which maintains frequency and tension on the optimized ranges, while the work cycle varies in according with the required thermal power.
• PWM Pulse With Modulation
• the PWM circuit may establish a control cycle on which there is a electric current flowing across the Peltier cell during 80% of the time, and along the remainder 20% the thermoelectric cell became inactive. If the required thermal power is reduced, the circuit changes the cycle, adjusting the current to a new parameter (for instance: by 50% of total time a current crossing the cell, and by the other 50% the cell is inactive ).
• This PWM circuit is self-adjustable, but it may also presents a external operated control, allowing to obtain predetermined operation parameters.
• the new refrigeration system is composed by a thermoelectric cell disposed in the wall of a refrigeration chamber or on a duct which conducts air or other fluid.
• the " cold " face of this cell is put inside of the chamber or duct, while the other face ( “warm ”) is connected to a heater exchanger.
• the said cell is electrically connected to a electronic circuit board which has a Pulse-With-Modulation ( PWM ) circuit comprising a pulse generator, a cycle controller and a power module.
• PWM Pulse-With-Modulation
• the circuit is supplied by direct current from a battery or an AC electric rectifier.
• the PWM circuit may control simultaneously two or more Peltier cells, disposed in series or in parallel connection; this assembly allows the construction of high power refrigeration sets.
• Fig. 1 schematic drawing of a basic electronic circuit for thermoelectric refrigeration and air conditioning devices, according with this patent;
• Fig. 2 block diagram of the same electronic circuit.
• the invention is a new refrigeration system composed by a thermoelectric cell ( 1 ) disposed in the wall of a refrigeration chamber ( 4 ) or on a duct which conducts air or other fluid, the " cold " face ( 3 ) of the cell ( 1 ) being on the inside of the chamber ( 4 ) or duct, while the warm face ( 5 ) is on the outside of the same chamber and connected to a heat exchanger ( 6 ), the said cell being electrically connected to a electronic circuit board ( 2 ) which has a pulse-with-modulation ( PWM ) circuit, which purpose is to maintain frequency and tension on the optimized ranges, while the work cycle varies in accordance with the required thermal power, the said circuit comprising a pulse generator ( 7 ), a cycle controller ( 8 ) and a power module ( 9 ), while the circuit receives DC electrical supply from a battery or from an AC electric rectifier.
• PWM pulse-with-modulation
• Higher refrigeration power sets may use a single PWM circuit ( 2 ), which controls simultaneously two or more Peltier cells ( 1 ), disposed in series or in parallel connection. All refrigeration and air conditioning devices equipped with thermoelectric elements and an electronic circuit, like the apparatus above described, differing only by their design, materials, size or other secondary characteristics, remains attached to he scope of this patent.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Control Of Temperature (AREA)
• Devices For Blowing Cold Air, Devices For Blowing Warm Air, And Means For Preventing Water Condensation In Air Conditioning Units (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4067290

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (5)

• 1997
  • 1997-08-27 BR BR9702789-8A patent/BR9702789A/pt not_active Application Discontinuation
• 1998
  • 1998-08-25 WO PCT/BR1998/000062 patent/WO1999010689A1/en active Application Filing

Patent Citations (5)

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