Patent Application
20130025295
1. Field of the Invention
The present invention relates to a temperature control element and a temperature control device for a motor vehicle, particularly for an electric or hybrid vehicle.
2. Description of the Background Art
No combustion waste heat for heating the passenger area is available in electric vehicles. Electrically resistive heating requires a considerable increase in battery capacity, which is generally very cost-intensive. Alternative heating methods and also cooling methods are therefore sought to reduce the need for electric power to maintain passenger comfort.
PTC auxiliary heaters or PTC thermistor auxiliary heaters are a possibility for electric vehicles without having to carry a fuel such as gasoline, bioethanol, etc., to cover the heating requirement for the passenger compartment in colder times of the year. PTC auxiliary heaters disposed on the air side are already being mass-produced for vehicles with at times limited waste heat, for instance, for modern diesel vehicles during a cold start. A form of realization here is, for example, a heater principle with layers of ribbing, glued one on top of the other, with PTC stones between the layers. In fact, this design is especially simple, because no frame, housing, tube, or the like surrounding the heating unit or parts thereof are needed, but there is a serial material connection with the particular adjacent layers because of the adhesive bonds. Because in this simple construction the ribbing itself carries current, but it is suitable solely for low voltage applications, e.g., for the 12 V on-board electrical system.
Another approach is a realization of a heating unit using Peltier technology. In this regard, e.g., prototypes of a heating unit with an alternative cooling function to support the AC circuit have already been proposed. In these prototypes, however, the design principle appears to be relatively complicated and three-dimensional; e.g., a great depth is necessary. The Peltier effect of thermoelectric materials is already utilized in niche applications for cooling, for instance, cooling of electronic components or in camping coolers. For applications in the automobile, the efficiency has been regarded thus far as being too low; in contrast the converse effect of current generation from temperature differences by means of thermoelectrics in the exhaust gas line of vehicles driven by internal combustion engines is propagated by well-known manufacturers in expert circles and developed in the direction of mass-production readiness. Thus far, the conventional cooling circuit is employed for air conditioning the passenger area, and electrical resistance heaters are largely relied upon for heating in first generation electric vehicles.
In the case of purely electric heating, high-cost electrical energy is converted to low-cost thermal energy. Two observations indicate otherwise. On the one hand, provision of electrical storage capacity, e.g., by means of Li-ion batteries, costs about 500-700 /kWh. The thus far envisaged technologies with Peltier elements are more costly to realize than heating with PTC auxiliary heaters because of the greater complexity of the electrical interconnections of alternating p- and n-doped components in the electrical series connection. Electrical insulators are usually also thermally insulating and worsen the heat transfers. The thermoelectrics at high driving temperature gradients are affected even more greatly than conventional heat pumps by the reduction of the COP or efficiency. Resistance heaters achieve only a COP=1 and have a great negative effect on the cruising range of the electric vehicle. The cooling circuit in principle works with an acceptable COP, but contains many individual components and must be topped up regularly with coolant. Overall, separate units for heating (heating unit) and cooling (cooling circuit) must be installed for each of the two functions.
It is therefore an object of the present invention to provide an improved temperature control element and an improved temperature control device.
The present invention is based on the realization that by a skillful series connection of Peltier elements, a heating or cooling unit in the layer design can be enabled in such a way that in each case similarly doped Peltier elements are arranged adjacent in a layer.
The use of Peltier elements differs from the use of PTC stones, among others, in the fact that two differently doped materials, therefore p- and n-doped elements, are interconnected. By default, the Peltier elements form such a configuration that a hot side of two differently doped Peltier elements and a cold side of two differently doped Peltier elements are connected in an electrically conducting manner, so that a series connection results overall. This type of configuration, however, can hardly be applied directly to a production-suitable heating or cooling unit, because the metallic conductors do not form a continuous bar, which goes beyond two differently doped, directly adjacent elements. The breaks could be bridged only by an electrical nonconductor. These nonconductors represent an obstacle for heat transfer on both sides.
The approach of the invention describes a heating unit with a possible cooling function for heating or cooling the passenger area of an electric vehicle, which can be produced as cost-effectively as possible with the lowest possible effort and already usable production technologies, and in addition has a high efficiency through heat transfer optimization.
A heating unit of the invention may have simple to produce, continuous bars for a ribbing and continuous channels for cooling water, which are made as electrical conductors. A high heat transfer can be realized by as direct as possible thermal connection of the Peltier elements on a liquid and/or air side; this can be attributed in particular to the fact that no electrical insulators are present in this area as heat barriers. Advantageously, this type of combination of series and parallel connections can be adjusted to 12 V. The heat transfer at ribs on the air side and a cooling water channel can be made two-sided according to an embodiment. This type of structure offers the further advantage that a possible thermal insulation effect of a galvanic separation, e.g., between the ribs, is not problematic, because there is no temperature gradient here owing to the symmetry requirement. Overall, there is an important advantage in a smallest possible departure from heating units already produced according to existing production methods, e.g., with PTC auxiliary heaters, with a simultaneously optimal heat transfer. Therefore, an optimal efficiency or COP (coefficient of performance) results. A basic design formed according to the approach of the invention here thus offers the advantage that it differs substantially in two points from a heating unit with a material connection. First, cooling water channels are already present as heat sources, for a heating mode, or as heat sinks, for a cooling mode. And second, an electrical insulation layer is present in the middle between the corrugated ribs. Operation of a heating unit of the invention with Peltier elements for a heating or cooling mode is accordingly such that net heat flows in sum occur only in the vertical direction and are to be understood in this way.
Advantageously, heating without combustion waste heat with a COP>1 and a combination of the functions of cooling and heating in one structure are possible. In addition, elimination of coolants and a simple decentralization through modularity result, because of the repeating layers and a repeating planar structure within a layer.
The present invention provides a temperature control element for a vehicle, with the following features: a first Peltier element layer; a second Peltier element layer; a first electrically conductive heat conductor layer for conducting a first heat transfer fluid; and a second electrically conductive heat conductor layer for conducting a second heat transfer fluid, whereby the first Peltier element layer, the second Peltier element layer, the first heat conductor layer, and the second heat conductor layer are arranged in the form of a stack, so that the first heat conductor layer and/or the second heat conductor layer are arranged between the first Peltier element layer and the second Peltier element layer, and whereby an electric current conducted through the stack brings about a temperature control of the first heat conductor layer and the second heat conductor layer due to a Peltier effect.
The temperature control element can be used, for example, in an electric or hybrid vehicle, to control the temperature of a passenger cell in the vehicle. Temperature control in this case can mean both heating and cooling. The first Peltier element layer and the second Peltier element layer can be formed from two differently doped semiconductor materials. Thus, for example, the first Peltier element layer can be n-doped and the second Peltier element layer p-doped or, vice versa, the first Peltier element layer can be p-doped and the second Peltier element layer n-doped. Instead of semiconductor materials, other suitable conductors can also be used for the Peltier element layers. The first and second electrically conductive heat conductor layer can be made from a highly conductive metal. A current applied to the temperature control element can enter at one end of the stack into the temperature control element, pass through the entire stack, and again leave it at an opposite end, for example, via suitable contacts that are connected to an electrical line. A heat transfer fluid can flow through the first and second electrically conductive heat conductor layer. The first and second heat conductor layer can be arranged in the stack relative to the first and second Peltier element layer, so that a temperature generated by the Peltier effect can be transferred to the heat transfer fluid being conducted in said layer. According to the Peltier effect and the arrangement of the heat conductor layers in regard to the Peltier element layers, one of the heat transfer fluids is always heated and the other cooled during operation of the temperature control element. The first and second heat transfer fluid can be in each case, e.g., a gas or a fluid. According to a temperature control element task to be achieved, one of the heat transfer fluids can be used to be conducted to a passenger cell of the vehicle in order to cool or heat said cell. If the current flow in the temperature control element is reversed, the heat transfer fluid, which was previously heated by the temperature control element, can now be cooled or vice versa. To prevent a leakage current via the heat transfer fluid, electrical insulation can be arranged between the heat transfer fluid and a surface, facing the heating fluid, of the heat conductor layer.
According to an embodiment, the temperature control element can comprise an additional first electrically conductive heat conductor layer and in addition or alternatively an additional second electrically conductive heat conductor layer. In this case, the additional first and/or additional second heat conductor layer can be arranged in the stack separated by at least one of the first or second Peltier element layer from the first or second heat conductor layer. For example, the stack can be structured so that the additional second heat conductor layer, on which the first Peltier element layer is arranged, is located at the very bottom of the stack. On this layer, the first heat conductor layer, on which the second Peltier element layer is located, can be arranged in turn. The second heat conductor layer can form the closure of the temperature control element stack. Alternatively, the stack can be built so that the additional first heat conductor layer forms the first layer of the stack. On this layer, for example, the first Peltier element layer, the second heat conductor layer, the first heat conductor layer, the second Peltier element layer, and the additional second heat conductor layer can be arranged one after another, whereby a thermal insulation layer can be arranged between the second heat conductor layer and the first heat conductor layer.
In case that the temperature control element comprises an additional second electrically conductive heat conductor layer, the second heat conductor layer can have a first electrical contact and the additional second heat conductor layer a second electrical contact. In this case, the first Peltier element layer and the second Peltier element layer can be arranged between the second heat conductor layer and the additional second heat conductor layer. The first heat conductor layer can be arranged between the first Peltier element layer and the second Peltier element layer. According to this arrangement, a first Peltier effect can be achieved at the first heat conductor layer, so that the first heat conductor layer can be heated or cooled according to a polarity of the current conducted through the stack. According to a Peltier effect opposite to the first Peltier effect, the second heat conductor layer can be heated when the first heat conductor layer is cooled or cooled when the first heat conductor layer is heated. This arrangement offers the further advantage that no thermally insulating layer is needed between the individual layers and differently temperature-controlled heat conductor layers are always separated by a Peltier element layer. In a stacking of the temperature control element with another similar temperature control element, moreover, only a galvanic separation and no thermogalvanic separation between the temperature control elements are necessary, because here two heat conductor layers are arranged adjacent to one another that are exposed to the same Peltier effect and thus have a similar temperature.
Alternatively, the temperature control element can comprise an additional first heat conductor layer and an additional second heat conductor layer. The first heat conductor layer can have a first electrical contact, and the additional first heat conductor layer can have a second electrical contact. Further, the temperature control element can have an electrical line for connecting the second heat conductor layer to the additional second heat conductor layer. In this regard, the first heat conductor layer and the second heat conductor layer can be arranged between the first and second Peltier element layer and the first Peltier element layer and the second Peltier element layer are arranged between the additional first heat conductor layer and the additional second heat conductor layer. A galvanic and thermal insulation layer can be arranged, moreover, between the first heat conductor layer and the second heat conductor layer. According to this arrangement, an electric current can enter the temperature control element at the first electrical contact and from there pass through the second Peltier element layer, the second heat conductor layer, and via the electrical line the additional second heat conductor layer, the first Peltier element layer, and finally the additional first heat conductor layer. At the second electrical contact, the electric current can be conducted out of the temperature control element and perhaps into an additional temperature control element.
According to a further embodiment, the different heat conductor layers of the temperature control element can also be connected together via additional electrical lines. The additional lines in this regard can be arranged in each case at the ends, opposite to the lines, of the particular heat conductor layers of the temperature control element. Accordingly, the heat conductor layers provided with a first or second contact can each have additional contacts for connecting the additional lines. This type of two-sided supplying and removal of the electric current on the left and right at the temperature control element, for example, by means of cables, can contribute to reducing the current strengths in the bars or ribs of the various heat conductor layers of the temperature control element. The disadvantage that in case of a one-sided connection the current strength at the entrance into the heat conductor layer, namely, the sum of all currents through the Peltier element conductors would correspond to a series, which can lead to unallowable current densities, can thereby be eliminated.
The first Peltier element layer can have at least two first Peltier element conductors arranged adjacent to one another, and the second Peltier element layer can have at least two second Peltier element conductors arranged adjacent to one another. A distance between the individual Peltier elements can be selected depending on a heat output of the Peltier element conductors. An electrical insulation can be arranged between the individual Peltier element conductors. Depending on the expanse of the Peltier element layers, accordingly many Peltier element conductors can be arranged adjacent to one another. In this regard, the Peltier element conductors can be arranged in a planar manner, therefore, for example, next to one another in both the longitudinal and transverse direction.
According to an alternative embodiment, the first Peltier element layer and the second Peltier element layer can each have at least one first Peltier element conductor and at least one second Peltier element conductor. The first and second Peltier element conductor in this regard can be arranged adjacent to one another and be connected in an electrically conductive manner. As a result, the electric current conducted through the stack can flow serially through the first Peltier element conductor and second Peltier element conductor. For example, the first Peltier element conductor can be n-doped and the second Peltier element conductor can be p-doped, or vice versa. This embodiment of the temperature control element offers the advantage that perhaps already available prototypes of heating elements based in Peltier technology can be used for constructing the temperature control element proposed here. This results in a saving of time and cost during production.
According to an embodiment, the first heat conductor layer can be configured as a coolant channel and the second heat conductor layer can be configured as a rib element. For example, the coolant channel can be formed as a tube for carrying a coolant fluid. The rib element can be formed, for example, from two bars, between which a zigzag-shaped or wavelike bent metal band is arranged, so that, for example, obliquely arranged ribs are formed between the bars. The second heat transfer fluid, for example, can be air, which is brought into the vehicle from the vehicle environment and is passed through the second heat conductor layer, where it is cooled or heated according to a temperature of the second heat conductor layer. This type of structure for the second heat conductor layer advantageously offers a large temperature transfer area for the fluid passed through the second heat conductor layer. Of course, the first heat conductor layer can be configured to carry air and the second heat conductor layer to carry a fluid. Likewise, the first heat conductor layer can have a plurality of adjacently arranged coolant channels and the additional heat conductor layer can have a plurality of adjacently arranged rib elements.
The first heat conductor layer can have a galvanic insulation layer on an outer side. It can be surrounded by a conductor layer, which can be formed to enable a current flow between the first Peltier element layer and the second Peltier element layer. For example, the first heat conductor layer can be surrounded completely by the conductor layer, or the conductor layer can be applied to two opposite sides of the first heat conductor layer and be connected to an electric line. The electric current flow through the temperature control element stack can be assured in this way, whereby at the same time the first heat conductor layer is excluded from an electric current flow. Thus, leakage currents in the coolant flowing through the first heat conductor layer can be prevented.
The first heat conductor layer and the second heat conductor layer can be configured to provide flow directions, orthogonal to one another, for the first heat transfer fluid and the second heat transfer fluid. In this way, inlets and outlets for the different heat transfer fluids can be arranged on different sides of the temperature control element.
The present invention provides further a temperature control device, which comprises a plurality of temperature control elements, whereby the plurality of temperature control elements are interconnected in a series connection via the respective first and second contacts.
According to an embodiment, a galvanic insulation layer can be arranged between two each of the plurality of temperature control elements. In this way, an electric current flow can be assured one after the other through all temperature control elements of the temperature control device. Contacts of a first and last temperature control device in regard to the current flow can be connected to a current source. Galvanic insulation layers arranged between adjacent temperature control elements can, moreover, provide a thermal insulation between the individual temperature control elements. This is especially important when two differently temperature-controlled heat conductor layers are arranged adjacent to one another in the temperature control device. The temperature control elements can be interconnected both in a series connection and in a parallel connection or in a combination form in the temperature control device.
The plurality of temperature control elements can be arranged in at least one stack. In this regard, a dimension of the temperature control device can be adapted to existing spatial circumstances by a suitable number of stacked temperature control elements and/or a horizontal extent of the individual layers of the plurality of temperature control elements. Of course, the temperature control device can also be formed from a plurality of stacks, which are arranged adjacently and are connected via the respective contacts in a series or parallel connection.
The present invention provides further a temperature control device for a vehicle, with the following features: a first heat conductor layer for conducting a first heat transfer fluid; a Peltier element layer which has a plurality of Peltier elements, which are arranged spaced apart from one another and each comprise a plurality of Peltier element conductors; and a second heat conductor layer for conducting a second heat transfer fluid, whereby the layers are arranged in the form of a stack, so that the Peltier element layer is arranged between the first heat conductor layer and the second heat conductor layer. During operation of the temperature control device, the Peltier element layer can be configured to cool the first heat conductor layer and to heat the second heat conductor layer, or vice versa. Each Peltier element can be made as a separate Peltier module. This means that each Peltier element has its own electrical connections for supplying and removing a current flowing through the Peltier element conductors of the Peltier element. The Peltier elements can each have a base plate on which solely the Peltier element conductors of the particular Peltier element are arranged. A distance between adjacent Peltier element conductors within a Peltier element can be smaller than a distance between adjacent Peltier elements. The Peltier elements can have both n-doped Peltier element conductors and p-doped Peltier element conductors. The Peltier element conductors can also be made as vapor-deposited conductive tracks or as a textile.
The plurality of Peltier elements of a Peltier element layer can cover a maximum of a tenth of the total area of the Peltier element layer. A thermally insulating interspace can be located between the Peltier elements. Alternatively, the plurality of Peltier element conductors can cover a maximum of a tenth of the total area of the Peltier element layer.
According to an embodiment, the temperature control device can have an additional Peltier element layer, which has a plurality of additional Peltier elements, which are arranged spaced apart from one another and in each case comprise a plurality of additional Peltier element conductors, and an additional first heat conductor layer for conducting the first heat transfer fluid. In this regard, the additional Peltier element layer can be arranged in the stack between the second heat conductor layer and the additional first heat conductor layer. In this way, no thermal insulation is needed between adjacent layers.
Alternatively, the temperature control device can have a thermal insulation layer, an additional first heat conductor layer for conducting the first heat transfer fluid, and an additional Peltier element layer, which has a plurality of additional Peltier elements (600), which are arranged spaced apart from one another and each comprise a plurality of additional Peltier element conductors. In this regard, the thermal insulation layer can be arranged in the stack adjacent to the second heat conductor layer and the additional first heat conductor layer in the stack between the thermal insulation layer and the additional Peltier element layer.
According to an embodiment, a temperature control device has a switching device, which is configured to conduct the first heat transfer fluid in a first operating mode of the temperature control device through the first heat conductor layer and the additional first heat conductor layer and in a second operating mode of the temperature control device either through the first heat conductor layer or through the additional first heat conductor layer. The temperature control element can be designed as a flap. The temperature control device can achieve a higher heat output in the first operating mode than in the second operating mode. Advantageously, an electric current, which has an optimal current strength for operating the Peltier element conductors, can flow through active Peltier element conductors both in the first operating mode and in the second operating mode.
According to an embodiment, adjacently arranged Peltier element layers, for example, the first Peltier element layer and the second Peltier element layer, can have a different number of Peltier element conductors or Peltier elements. Alternatively or in addition, an arrangement of Peltier element conductors or Peltier elements on adjacently arranged Peltier elements layers can be different. Alternatively or in addition, an extended area for the Peltier element conductors or the Peltier elements on the adjacently arranged Peltier element layers can be different. A temperature distribution within the Peltier element layers can be influenced by a suitable selection of the arrangement, number, and/or size. A homogeneous temperature distribution in particular can be achieved.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
In the following description of the exemplary embodiments of the present invention, the same or similar reference characters are used for elements with a similar action and shown in the various drawings, whereby a repeated description of these elements is omitted.
Each temperature control device 105 in
In the exemplary embodiment of temperature control device 100 in
According to the exemplary embodiment of temperature control device 100 as shown in
Each heating unit or each temperature control element 105, according to the illustration in
Coolant flows through coolant channels 120. Peltier elements 135 are attached to these on both sides, so that heat transfer can occur in both directions. The heat is transferred via Peltier elements 135 and reaches the ribbed air side 125, 130, and ribs 125, 130 facilitate the heat transfer to the air. This heat path is also made electrically continuously conductive, because the electrically conductive heat conductor layers 120, 125, 130 are made of metal, e.g., aluminum, and Peltier elements 135 contain thermoelectrically active functional material. Electrical insulation layer 140 is located in the middle between corrugated ribs 125, 130. A possible heat transfer resistance by insulation layer 140 plays no role, because according to the symmetry no heat transfer occurs here in the vertical direction within the meaning of the operating principle.
Peltier elements 135 in
According to the illustration in
Depending on the construction, naturally also layers not directly adjacent could be interconnected together, but adjacent layers because of the shortest needed line length are obvious and to be preferred. Likewise, a temperature control element layer 105 could be rotated 180°, so that the same doping does not always lie on top and the other doping on the bottom. However, the always invariable arrangement of the layers of temperature control elements 105, as shown in
In summary for the exemplary embodiment of temperature control device 100, as shown in
According to the illustration in
In regard to the exemplary embodiments explained with the previous
Alternatively to the exemplary embodiments of temperature control devices 100, 200, 400, as presented according to
An exemplary embodiment of a temperature control device of the invention can be built according to the principle of temperature control devices 100, 200, 400 shown in the
According to an embodiment, in which Peltier elements 600 are used, a current flow occurs not through the entire stack, and particularly not through the heat conductor layers, but solely through the Peltier element layers. The individual Peltier element layers can each be connected parallel or serially.
Depending on the voltage drop at Peltier elements 600, it would be possible to also use the electrical interconnection described here between the rows to increase further the total voltage drop across the heating unit. Alternatively, simply each row with thermoelectric elements 600 can be treated separately as a single circuit, when, e.g., the fine structure of Peltier module 600 already causes a voltage drop of 12 V, which corresponds to the conventional functionality. For example, an n- or p-component or n- or p-Peltier element conductor can have a voltage drop of 0.0625 V. With 16 components, this would result in 1 V for a Peltier element. If heating unit 12 has serially connected rows, a 12 V voltage drop would be realized overall.
An occupancy rate ε can be less than or equal to 10%:
ε=(sum of the areas of the Peltier elements 600)/(area of layer 710)=<10%
Peltier element 600 has a base plate and a cover plate, between which a plurality of Peltier element conductors is arranged. The Peltier element conductors can be arranged according to the arrangement shown in
According to the exemplary embodiment shown in
According to an exemplary embodiment, the approach of the invention can be used in a thermoelectric heating and air-conditioning device. A device with a modular structure is used for heating or cooling the internal compartment air. The heat absorption or heat dissipation occurs via the low-temperature circuit of the vehicle, preferably an electric vehicle. In order to be economical with commercially available thermoelectric materials, the basic design of the device is conceived for the best possible heat transfer.
In the electric vehicle, heating of the passenger area represents a challenge, because no notable engine waste heat is available. Electrical resistance heaters convert the current stored in the battery with a COP=1 (coefficient of performance) into heat and reduce the cruising range significantly. More efficient are heat pumps that operate with a COP>1 and recover heat in part from current, in part also from the environment or from waste heat sources with low temperature levels. Apart from the use of coolant-heat pumps, thermoelectric materials are also suitable which could produce the effect without moving parts and without coolant. An ideal situation would be when the cooling function for the passenger area (summer operation) could be realized by means of the same thermoelectric elements, because then the cooling circuit would be completely eliminated and the switching between heating and cooling would be accomplished by changing the polarity of the applied voltage without mechanical changes.
The approach of the invention makes it possible to accomplish the function “heating of the passenger area” with a COP>1 (heat pump operation) and to eliminate the separate cooling circuit by electrical switching to the cooling operation, whereby the COP in the cooling operation should not be inferior to the COP of a cooling circuit.
The essential feature of a heating and air-conditioning device with utilization of the Peltier effect is a considerably increased heat transfer with the lowest possible temperature differences between fluid and the thermally connected side of the thermoelectric elements. Because the efficiency of heat exchangers rapidly reaches its limits, the solution remains to bring about small driving temperature differences by a significant reduction of the transferred heat flux density. The association between decreasing COPs at greater temperature differences is much more greatly pronounced in thermoelectrics than in cooling circuits, because undesirable heat conduction in a natural heat flow direction occurs between the warmer and cooler side of a Peltier element. A few Kelvin in the cooling operation can already constitute the difference between an acceptable use and a no longer economic or even a physically no longer possible configuration, because the following feedback mechanism is present: Rather poor COPs cause a greater amount of heat on the waste heat side and increase the temperature there, which in turn worsens the COP and further increases the power requirement and heat amount on the waste heat side.
During the reduction of the power density, one cannot simply reduce the supplying of current to the thermoelectric element, because here the COP would worsen severely, and the elements remain as undesirable thermal bridges between the hot and cold side. The employed semiconductors usually have thermal conductivities in the single-digit range (W/m2K). Instead, the Peltier elements must be supplied with an optimal current strength to be calculated or as a characteristic diagram to be provided, and for reducing the power density may only occupy a small portion of the area of their particular integration-surface layer. The portions of the area not occupied by the thermoelectric material are to be filled, for example, with insulation material, with air, or with gas, as is shown in
The low power density based on a surface layer of Peltier elements must be compensated in the remaining dimension by successive layers as close as possible, so that overall an acceptable volumetric power density is available and the combination heating/cooling device is not built too large, as is shown in
The desired advantages and effects can be amplified by countercurrent flow of the passenger area air and coolant, as is shown in
During cold operation with a 1200 W cooling capacity, 15° C. exhaust temperature, 35° C. coolant temperature, dimensions of 150×150×300 mm3, 10 coolant layers, realistic air and coolant flows, and suitable thermoelectric material, a=>COP=Qcold/Pelectric=2 can be realized.
The heating and cooling unit is designed so that the maximum COP at one or more relevant operating points can be approximated as closely as possible. At a lower power requirement, therefore a reduced current supply, the COP would worsen, because the Peltier elements act increasingly as a natural thermal bridge. Therefore, after values fall below a certain power level, individual layers are separated not only electrically, but also thermally from the air stream in that, e.g., flaps close the inlet. This possibility can be realized for a certain number of individual layers, or also overlapping for a number of layers. A finer gradation improves the COP over the operating cycle, and a rougher gradation reduces the cost of production.
For example, 12 layers can be provided in a heating and cooling unit. Of these, in the case of a total of 6 layers, 3 layers each can be closed jointly on the air side. Thus, 2 flaps are needed. The number of simultaneously passed-through layers can therefore assume the following values: 6 layers if two flaps are closed, 9 layers if one flap is closed, and 12 layers if all flaps are open.
Further, the component is to be dimensioned so that during heat-up or cool-down, i.e., during heating and cooling, the required heating or cooling performance can be achieved, independent of the COP achieved in these phases.
According to this exemplary embodiment, the front Peltier element layer and the back Peltier element layer have a different number of Peltier elements 600, 1600. By way of example, the front Peltier element layer has 16 Peltier elements 600 and the back Peltier element layer 9 Peltier elements 1600. Moreover, Peltier elements 600 have a different arrangement on the front Peltier element layer than Peltier elements 1600 on the back Peltier element layer. Shown is a staggered arrangement in which a row or column with Peltier elements 600 alternates with a row or column with Peltier elements 1600. In this regard, Peltier elements 600 have no overlapping areas relative to Peltier elements 1600. According to this exemplary embodiment, Peltier elements 600 and Peltier elements 1600 each have the same size. Peltier elements 600, 1600 can be identical. Alternatively, Peltier elements 600, 1600 can be different in size.
Ideally, in each case a surface of a Peltier element layer has a homogeneous temperature distribution. In reality, however, corresponding temperature maxima or temperature minima, so-called hot spots and cold spots, develop at Peltier elements 600, 1600, which represent heat sources or heat sinks. This is caused by the fact that the horizontal heat conduction is limited. The planar arrangement and number of Peltier elements 600, 1600 and in addition or alternatively, the element size of Peltier elements 600, 1600 can vary between two adjacent Peltier element layers. This can result in the advantage of reducing the formation of hot spots or cold spots, in that the heat sources or heat sinks, which, for example, act on a ribbing, turbulators, or a fluid, in the conceptual vertical projection, shown in
The described exemplary embodiments have been selected only by way of example and can be combined with one another. Particularly, a combination of the exemplary embodiments with Peltier element layers made up of individual Peltier element conductors and the exemplary embodiments with Peltier element layers made up of Peltier elements is possible. In this regard, the electrical interconnection of the Peltier element layers can be adjusted accordingly.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| DE102010013467.8 | Mar 2010 | DE | national |
| DE102010019794.7 | May 2010 | DE | national |
| DE102010027470.4 | Jul 2010 | DE | national |
| DE102010043620.8 | Nov 2010 | DE | national |
This nonprovisional application is a continuation of International Application No. PCT/EP2011/054878, which was filed on Mar. 30, 2011, and which claims priority to German Patent Application No. DE 10 2010 013 467.8, which was filed in Germany on Mar. 30, 2010, German Patent Application No. DE 10 2010 019 794.7, which was filed in Germany on May 6, 2010, German Patent Application No. DE 10 2010 027 470.4, which was filed in Germany on Jul. 16, 2010, and German Patent Application No. DE 10 2010 043 620.8, which was filed in Germany on Nov. 9, 2010, and which are all herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2011/054878 | Mar 2011 | US |
| Child | 13632468 | US |
