FR2744794A1 - Heating and cooling module using Peltier effect - Google Patents

Abstract

Each thermo-electric unit (18) houses four semi-conductor thermocouple assemblies, based on e.g. tellurium or selenium, associated with lead, bismuth or antimony, series-connected via top and bottom aluminium plates. These units are stacked within an aluminium case (20), insulated by polyurethane foam (23) from an outer casing (21) on a finned radiating base (61). A screwed-down (24, 26) lid (25), also foam-insulated (29), contains a serpentine heat exchanger coil (27) set against the top unit. Electrical connections (22) penetrate the double casing. For room heating or cooling a pump circulates a water/glycol mixture through the heat exchanger and a conventional radiator. A fan directs air towards or from the latter, as required. Similar arrangements apply in a vehicle, with the module incorporated in the engine coolant circuit.

Description

 The present invention relates to a device for heating or cooling a mass.

Traditionally, the temperature rise of a mass is done by electrical resistance using the Joule effect. However, it is cooled by gas expansion using a compressor and an evaporator
If the heating by resistance is of a simplicity, there is not a MINE for cooling. In the case of a room, its cooling requires an additional device called air conditioner. As for a vehicle, the efficiency of the engine and its consumption are penalized when the compressor is in service for air conditioning.

 The device according to the invention makes it possible, with the same device, to carry out these two operations.

 On the other hand, the conditioned air production of a vehicle becoming independent of the engine, the necessary energy being supplied by the battery, it is interesting to install a second thermoelectric block which, operating only in the cold position, will improve the cooling of the engine and lower the temperature of the engine to obtain better performance by reducing mechanical overheating.

 The device consists of a thermoelectric block using the Peltier effect to produce the research effect. I1 is made of three stages mounted in thermal series, each stage being made up of four modules grouping several thermoelectric couples, their number depending on the desired power, composed of semiconductors allowing the Peltier effect to be used with maximum efficiency . For this, it is possible to use, inter alia, tellurium or selenium compounds combined with heavy metals such as lead, bismuth or antimony. These four modules made up of several pairs will be mounted in thermal parallel. The power supply for this block will be in series for all of its components. Associated with this block, a pump allows, through a coil, to transfer via a liquid, hot or cold, depending on the desired choice.

 To complete the operation, in the case of a room, a fan will blow air either upwards when it comes to cooling, or downwards when it comes to heating. Its flow will be proportional to the desired temperature. In the case of the passenger compartment of a vehicle, the exchange will be made from the air taken from outside and brought inwards. It is also possible, by obstructing the entry of outside air, to do an internal recycling as is currently the case for vehicles equipped with air conditioning. As regards the engine, the temperature of the refrigerant added to the conventional cooling circuit will depend on the surrounding temperature of the engine.

 The accompanying drawings illustrate the invention: FIG. 1 represents a module composed, for example, of three thermoelectric couples, the construction of which has been described by H.J. Goldsmid in the work entitled Applications of Thermoelectricity, New York, 1960 n.

-Figure 2 shows the assembly of four modules in thermal parallel and electrical series which will compose a stage.

FIG. 3 represents a section of a stage. FIG. 4 represents the thermoelectric block composed of three stages assembled in thermal and electric series.

FIG. 5 represents the cover of the block which contains the coil serving as a heat exchanger.

FIG. 6 represents the device, according to the invention, of the thermoelectric assembly associated with a space heating radiator for liquid premises and its components.

FIG. 7 represents the control panel of the radiator seen from the front.

FIG. 8 represents the electrical diagram of the heating radiator and thermoelectric block assembly.

FIG. 9 represents the device, according to the invention, of this same assembly for the air conditioning of a passenger compartment of a vehicle with an outdoor air version.

FIG. 10 represents the specific version of an internal combustion engine allowing better cooling according to the invention.

With reference to these drawings, the device consists at the start of thermoelectric modules (fig.l) composed of semiconductor elements produced, for example, from bismuth telluride which will, according to the enrichment, of type N ( l) or
P (2). The electrical connection between the elements will be by welding on aluminum plates (3) and the insulation by Bakelite insulating plates (4) which will take their final position before the assembly of the high connections (5).

The external electrical connections will be made from the elements (6) by welding wire on the connection elements in the grooves (7) provided for this purpose.

 The electrical connection (fig.2) by the wiring (8) of these four modules (9) will be shown by a top view.

Each module will be positioned in the same plane and electrically isolated from the others by Bakelite plates (10).

External connections (power supply between floors) will be made by conductors (li).

 The section along AA (fig. 3) shows the assembly of the modules to form a stage (18). Each module will be placed on a surfaced aluminum plate (12) with an interlayer sheet of mica or quartz (13) to ensure electrical insulation and thermal conductivity. The same assembly will be used for the upper part. This assembly will be maintained by a frame (14) made of welded aluminum angles. On these angles will be welded reinforcing squares (15) allowing the passage of a fixing screw (16) or having a thread (17) which will be used to tighten the assembly.

 The three stages (18) will be assembled in thermal and electrical series (fig. 4). Each stage will be superimposed in an aluminum enclosure (20) whose dimensions will be adjusted alongside them. The rectified flat bottom of this enclosure will allow good thermal contact with the outside. This enclosure will be placed in another container (21) which will have orifices intended for the passage of the connection targets for the electrical supply (22). Polyurethane foam (23) will be injected between the two envelopes to ensure thermal insulation of the thermoelectric block with the outside.

Four fixing points (24) welded on the external casing and taps will ensure the mechanical connection with the cover (25). by means of screws (26). The cover (25) will contact a coil (27) with one end of the thermoelectric block. An aluminum fin radiator (61) will be fixed on the external face of the enclosure (21) in opposition to the coil (27) to facilitate heat exchange with the outside of the junctions which will be cold or hot depending on use and will bring their temperature closer to the ambient temperature and will thus contribute to a relative stabilization of these. A thermistor (39) will indicate the temperature of the coil. The external temperature of the cover will be transmitted by the thermistor (40).

 The connection of the entire thermoelectric block with the outside will be done by a suitable cover made up of two parts (fig. 5). The first is a cast aluminum block (28) which has a housing intended to receive the coil (27) which will ensure, by conduction through a liquid composed of a water-glycol mixture, the transfer of heat or cold, to the devices concerned. This block will be maintained by the cover (25) which, hollowed out in its central part, will prevent heat losses by injected polyurethane foam (29), the maintenance of the assembly being ensured by the screws (26).

 The heating radiator (lamellar or fins among others) & liquid (30) will be equipped with a thermoelectric block fixed vertically (fig. 6). This block (31) will have its heat exchanger in the low position. One end of the coil (27) will be connected to the upper manifold of the radiator by a flexible hose placed in a sheath & thermal insulator (32). The other outlet will be connected to an electric pump (33) which will itself be connected to the lower collector of the radiator (34) under the same conditions. The sector will supply the control panel (35>.

The device will be completed by a reversible fan & flow (43). Composed of horizontal fins (44), two horns, one facing upwards (45), the other inclined downwards (46) will serve one to suck in air, the other to propel it. The direction of rotation of the motor will depend on the cold or hot choice. The flow will be directed upwards for cold or downwards for hot. The fan motor (47) will be attached to the side.

The different controls (fig. 7) will be grouped together on a control panel (35). Among other things, there will be the switch
on-off (36) of the system which can be accompanied by operating indicators. The power will depend on the position of the rheostat (37) which will determine the value of the voltage. The inverter (38) will allow you to choose heating or cooling.

 The diagram (fig. 8) shows the different elements making up the system. The switch (36) will connect the sector to a rectifier (44). The rectified voltage will supply the regulator (45) which will supply a variable voltage from zero & a few volts depending on the position of the rheostat (37). A thermistor (39) located in the cover (25) transmits the temperature value of the coil (27). Another wave (40) will measure the external temperature. These two measurements will be compared by the amplifier system (41). if the difference between the two temperatures is too great, the amplifier (41) will supply the relay (42) which will cut the power supply to the system this in order to avoid thermal shocks. When the differential between the two temperatures will become low again , the relay will return to zero position. This solution avoids going suddenly from cold to hot or vice versa without waiting times. The inverter (38), in addition to selecting the cold or hot temperature, will determine the direction of rotation of the pump (33), the production of heat being directed towards the bottom collector, that of the cold upwards as well as the direction of the fan (43).

 Regarding the air conditioning of a vehicle (figs) the principle will be identical to that of the room except the continuous supply which will be made from the battery (48). The controls for heating or air conditioning (49) with external air blower or recycling will be identical to those existing on vehicles.

The thermoelectric block (31) will replace the compressor and the evaporator. The coolant or refrigerant, depending on the choice, will be brought by the pump (33) into a finned exchanger (50). The molded fin radiator (61) fixed near the end (21) of the block will be located near a wing to undergo as little as possible the influence of engine heat.

The exchanger (50) will be located in a sheath (51) which will serve as a blower. The outside air will be supplied by the fan (52) to the cabin ventilation duct (53).

 The engine cooling circuit will be improved (fig.lO) by connecting the thermoelectric block (31) in parallel. The radiator (54) will serve as the main engine cooling. The hoses (55) will transfer the liquid through the pump & water (56) to the engine block. The membrane thermostat (57) of the main circuit will open when the set low temperature is reached. The thermostat of the secondary circuit (58) will let the liquid pass to the thermoelectric block when the so-called average temperature is reached. A thermistor (59) allows the control circuit (60) to operate at the average temperature of the thermoelectric block as well as the power necessary to ensure lower and stable cooling of the motor.

Claims (5)

 1) Device for heating or cooling a mass characterized by the thermal parallel assembly of three or more thermoelectric couples composed of semiconductor elements specially performing for the use of the Peltier effect such as bismuth tellurides which will constitute a module which will form themselves, in groups of four, and located in the same plane, stages (18) which, mounted in thermal series and assembled in an enclosure (20), isolated from the outside by polyurethane foam (23) injected into a second envelope (21), will form a thermoelectric block which will transmit, via a coil (27), a coolant or refrigerant to the elements concerned, the opposite side being in contact with an aluminum radiator (61) to facilitate heat exchange with the outside.  2) Device according to claim 1 for heating or cooling a mass characterized by a thermoelectric block (31) associates a heating radiator (30) by means of a liquid which will be coolant or refrigerant depending on the direction of the applied electric voltage the transfer of which will be by a pump (33) and the diffusion by a fan (43).  3) Device according to claim 1 characterized by a control (35) for simultaneously determining the power of the system (37), the direction of transfer of the liquid (38) as well as the flow rate of the pump (33) and the direction of the breath of the fan (43).  4) Device according to any one of the preceding claims, characterized by an adaptation on a vehicle made possible by the replacement of the radiator (30) by a finned exchanger (50).  5) Device according to any one of the preceding claims, characterized by the provision of a parallel cooling circuit an engine by a thermoelectric block (31) controlled by the control block (60) controlled by the mechanical thermostat (sus) and & thermistor 59).