DE102021207803A1 - Energy supply arrangement comprising an electronic circuit as a heat source and a heat exchanger - Google Patents

Abstract

The invention relates to an energy supply arrangement (100) having an electronic circuit (136) for supplying energy to an energy sink from an energy source, a flexible cable (120) connected to the electronic circuit (136) for electrically connecting the electronic circuit (136) to the energy source or the energy sink , wherein the cable (120) has at least one electrical line (120a) for transmitting electrical energy and at least one heat exchanger (120b, 120c), the heat exchanger (120b, 120c) containing a working medium for dissipating heat from the electronic circuit (136 ) into the cable (120), wherein the electronic circuit (136) is designed as a heat source and the cable (120) as a heat sink.

Description

The present invention relates to an energy supply arrangement having an electronic circuit as a heat source and a heat exchanger.

Background of the Invention

From the EP 3 511 952 A2 a charging cable device for a rapid charging station for rapid charging of a battery of a vehicle with an electric drive with a temperature control device and a charging cable connected thereto is known, the charging cable having fluid lines which extend from an end of the charging cable facing the temperature control device to an end remote from the temperature control device and are connected to one another at the end remote from the temperature control device. The temperature control device is connected to the fluid lines of the charging cable to form a fluid circuit, the temperature control device being designed to heat a fluid in the fluid circuit. The handling of the charging cable should be improved by heating the charging cable before use.

Conversely, for example, from the DE 10 2011 100 389 A1 a charging cable for transferring electrical energy to an energy store of an electric or hybrid vehicle is known, the charging cable comprising a cable sheath, at least one first electrical conductor and at least one coolant-conducting device, the first electrical conductor and the coolant-conducting device being arranged within the cable sheath, the charging cable being a cable for direct current transmission. The coolant-guiding device serves to cool the first current conductor in particular and, if necessary, additional current conductors.

Disclosure of Invention

According to the invention, an energy supply arrangement with the features of claim 1 is proposed. Advantageous configurations are the subject of the dependent claims and the following description.

The energy supply arrangement has an electronic circuit for supplying energy to an energy sink from an energy source and a flexible cable connected to the electronic circuit for electrically connecting the electronic circuit to the energy source or the energy sink. The cable has at least one electrical line for transmitting electrical energy and at least one heat exchanger, with the heat exchanger containing a working medium for dissipating heat from the electronic circuit into the cable, with the electronic circuit being designed as a heat source and the cable as a heat sink.

In other words, the invention relates to an energy supply arrangement in which the waste heat from an electronic circuit, which is provided for the energy supply of an energy sink, is transferred into the cable as a heat sink. In this way, the temperature of the electronic circuit can be kept within desired limits, even in heavily loaded operation. The length of the cable and the heat exchanger running in it determine the heat that can be dissipated. The heat exchanger is not used to conduct heat through the cable to a separate heat sink such as a cooler without significant heat dissipation, but rather gives off the heat itself to the environment. The length of the cable and its circumference provide a large area for dissipating heat, so that local cooling of the electronic circuit, e.g. with a fan, is not required.

The electronic circuit can be operated in particular as charging or power supply electronics, for example as a rectifier, alternator and/or converter, so that the energy supply arrangement is suitable for different areas of use. The energy supply arrangement can in particular have two cables, one for connection to the energy source and one for connection to the energy sink.

The invention is particularly suitable for so-called charging cables for electric vehicles if these charging cables themselves have an electronic circuit, for example in the form of a so-called in-cable control box (ICCB for short). and protection device, charging line-integrated control and protection device, IC-CPD for short). In particular, the electronic circuit has a converter for converting alternating current (for example from a household socket or charging station socket) into direct current (for the vehicle). Advantageously, by using such a charging cable or such a power supply arrangement, a rectifier or inverter that was previously usually provided in the vehicle can be eliminated. If the infrastructure-side energy source only provides alternating current, for example, the conversion to direct current can take place in the charging cable. Conversely, if energy is to be made available to an end consumer from the vehicle, the electronic circuit can, for example, convert the DC voltage provided on the vehicle side into an AC voltage desired by the consumer. Such electronic circuits can during operation, e.g. during a charging process, become very warm and require active cooling - e.g. by means of fans. However, such fans take up a lot of space. At the same time, it must be ensured that no moisture or moisture gets close to the electronic circuit. However, passive cooling (without a fan) is possible with the invention. The heat exchanger can run in the cable between the electronic circuit and the energy sink (vehicle) and/or energy source (socket). The greatest possible heat dissipation can thus be made possible. With the invention, the smallest possible size of the electronic circuit or the housing surrounding it can be achieved, with the temperatures remaining as low as possible on the outer surfaces of the housing, in particular not leading to burns when touched briefly. Furthermore, advantageously, by means of the invention, such a housing can be provided in a simple and cost-effective manner, which has a high degree of tightness against moisture and moisture present outside the housing and against dirt.

A flexible cable is understood to mean a cable which, for example, can be easily rolled up or folded in such a way that it can be stowed in a recess in the trunk of a vehicle. The heat exchanger is therefore also advantageously flexible.

Advantageously, the working medium in the heat exchanger is in a gaseous and liquid mixed phase, ie in two phases. This means that it also has essentially the same temperature everywhere in the heat exchanger. The heat content is determined by the proportions of the gaseous and liquid phases. In this way, particularly hot spots in the cable, which would damage the cable or injure or burn a user, can be avoided. In particular, the outside temperature of the cable should not exceed an upper temperature threshold of e.g. 60°C at any point.

Working media suitable for the invention include, in particular, organic refrigerants, for example R1233zd, R1234ze, R1234yf, as well as water, ethanol, acetone, methanol, glycerine, ethylene glycol or other antifreeze agents, in each case pure or in a mixture. These are tested and reliable and allow you to reach the desired temperatures.

The energy supply arrangement expediently has an evaporator for the working medium, which is in thermal contact with the electronic circuit and is in fluid connection with the heat exchanger. The heat can thus be transferred particularly effectively from the electronic circuit as a heat source to the working medium. In particular, the evaporator is in immediate or direct thermal contact with the heat source; so there is a heat conduction from the electronic circuit in the evaporator.

The evaporator has a jacket and a cavity in it, in which the working medium is located. The evaporation of the working medium in the evaporator extracts heat from the electronic circuit. The heat is then initially in the gaseous phase and is transferred to the cable by means of the heat exchanger, whereby the gaseous phase completely or partially changes into the liquid phase and can thus give off heat to the environment.

According to a preferred embodiment, the heat exchanger has at least one forward channel and at least one return channel that is fluidly connected to the forward channel, which are each in fluid communication with the evaporator and contain the working medium. The at least one forward channel directs the working medium away from the evaporator, and the at least one return channel directs the working medium back to the evaporator. The forward channel and return channel are thus characterized by the direction of flow of the working medium relative to the evaporator. The transition from the forward channel to the return channel is the point of the heat exchanger furthest away from the heat source. In particular, it is designed as a simple direct fluid connection, for example in the form of a curve or loop. It is also possible to provide several outward and return channels in order to generate the largest possible surface area or in order to be able to dissipate as much heat as possible from the electronic circuit.

In this sense, the heat exchanger is also designed in the form of a so-called "Loop Heat Pipe" (LHP). In the evaporator, the working medium is converted from the liquid to the gaseous state by the heat absorbed by the heat source. The pressure increase caused by this, together with a capillary effect, causes the working medium to circulate through the forward and return channels. However, in contrast to conventional LHP applications, there is no additional capacitor. Rather, the heat exchanger itself acts as or is the condenser. Transport lines that are usually present up to a condenser are thus advantageously omitted or are only designed to be greatly shortened. In other words, the ratio of the gaseous and liquid phases to one another is generally greatest at the inlet of the forward channel and then generally decreases gradually over the length of the forward and reverse channel and is generally smallest at the outlet of the reverse channel. As explained, the forward channel is in and out duct of the return channel is connected to the evaporator in a fluid-conducting manner. With such an embodiment, very large distances of up to a few meters can advantageously be bridged. On the other hand, the heat transport can take place independently of gravity. For example, height differences of at least 1.5 m or 2 m can be overcome by means of the pressure difference between exit from the evaporator and re-entry into the evaporator and by capillary action. This is advantageous if, for example, a charging cable is connected to an elevated socket, be it on the vehicle or on an infrastructure-side energy source. Because then the cooling continues to work autonomously. The passive movement of the liquid thus advantageously simplifies the necessary technology. Outgoing and return channels are flexible and pliable and can therefore be routed or processed in a simple manner.

The at least one electrical line advantageously runs closer to a central axis of the cable than the at least one forward channel and the at least one return channel. In other words, the at least one forward channel and the at least one return channel are located further outside than the electrical line, viewed in the radial direction. As a result, heat can be dissipated particularly effectively to the environment via a sheathing of the cable, since the electrical line does not represent a heat barrier.

More preferably, the at least one forward channel and/or the at least one return channel directly adjoins a sheathing of the cable, which allows very effective heat dissipation to the environment.

The at least one forward channel and the at least one return channel are preferably arranged symmetrically to the central axis of the cable. The heat output can thus be increased. If several outward and return channels are provided in each case, these are preferably arranged alternately in the circumferential direction and preferably evenly distributed. This also leads to an improvement in heat dissipation.

According to a preferred embodiment, the heat exchanger is designed as a polymer hose. It can be a synthetic or natural polymer, in particular silicone or rubber. A flexible heat exchanger can thus be provided in a particularly simple manner.

The heat exchanger is preferably designed to be pressure-resistant up to at least 1 bar, more preferably up to at least 5 bar. It goes without saying that a differential pressure of the working medium to the environment or overpressure is relevant in each case. A pressure resistance of 25 bar is particularly preferred in preferred applications. In this way, numerous preferred two-phase working media can be kept within a desired temperature range of, for example, 40°C to 80°C. In this way, a sufficiently high level of heat emission from the electronic circuit to the heat exchanger can be ensured, so that the electronic circuit does not have to be limited and there is no risk of damage to the heat exchanger. For example, the vapor pressure of R1234ze at 60°C is around 12.5 bar. A compressive strength can be achieved by an appropriate jacket thickness and/or by measures to limit expansion, e.g. by means of an enveloping mesh or a metal spiral embedded in the jacket.

The power supply arrangement expediently has two ends, each with a plug, for example a CCS plug, CEE plug, Type 2 plug, Schuko plug, etc. In this way, a charging cable for an electric vehicle in particular can be provided particularly easily. A solution in which the above-mentioned transition from the forward channel to the return channel is arranged in a connector offers particular advantages. This can only be done, for example, in the form of U-shaped tube sections, e.g. made of plastic or metal. The cable can then be provided as an endless or rolled product, with a cable required for the specific application simply being cut to length. In this way, a maximum possible surface area of the cable is also used particularly advantageously for dissipating heat from the desuperheater. If the heat exchanger extends in both directions, starting from the electronic circuit, such a transition from the forward channel to the return channel can also be expediently arranged in each plug, for example. It goes without saying that in other cases it is also possible to lay the continuous heat exchanger in the plug.

According to a development, the energy supply arrangement has a pump for conveying the working medium through the heat exchanger. In particular, this represents an alternative to the "loop heat pipe" solution mentioned, which is designed for particularly large flow rates and/or particularly long cables. In this case, the energy supply arrangement can be designed in particular in such a way that the working medium is only in the liquid phase, i.e. single-phase. Nevertheless, even in such a case, the heat is dissipated over the length of the heat exchanger in the cable and not predominantly in a separate cooler or a separate heat sink.

Further advantages and refinements of the invention result from the description and the accompanying drawings.

The invention is illustrated schematically in the drawings using exemplary embodiments and is described below with reference to the drawings.

character list

• 1 shows in partial views a to f a preferred embodiment of an energy supply arrangement according to the invention in a sectional view with additional perspectives.
• 2 shows in partial views a to e another preferred embodiment of an energy supply arrangement according to the invention in a sectional view with additional perspectives.

embodiment(s) of the invention

In 1 is a preferred embodiment of an energy supply arrangement according to the invention in the lower part ( 1a) shown in a schematic sectional view and denoted overall by 100 . above ( 1b , 1c , 1d , 1e) The sectional view shows details of the energy supply arrangement 100 in a perspective view to explain the individual components ( 1b , 1d , 1e) and a cross-sectional view ( 1c ) shown. Below ( 1f) The sectional view shows an enlarged section for explanation 1a shown.

The energy supply arrangement 100 has in 1a illustrated example from left to right a connector 110, a flexible cable 120, a housing 130 and another flexible cable 140 with connector (not shown).

A longitudinal direction or an axial direction A of the cable 120 (shown here in the unrolled state) extends from left to right in the figure. In the cross-sectional view ( 1c ) the central axis of the cable 120 runs centrally, towards the edge, perpendicular to the central axis and to the axial direction A, a radial direction R extends.

The cable 120 with plug 110 is used here, for example, to connect the energy supply arrangement 100 to an energy sink, e.g. a vehicle, and the other cable 140 with plug, for example, to connect to an energy source, e.g. a socket. The plug 110 can thus be a charging plug for an electric vehicle, for example. The energy supply arrangement 100 as a whole can be used as a charging cable for a vehicle in order to charge it, for example, at a household socket or charging station socket. In principle, however, the energy supply device 100 can also be operated in the opposite direction of current flow. In this case, electrical energy is taken from the vehicle and made available to a consumer, which can be connected to a socket connected to the additional cable 140 .

In this exemplary embodiment, an electronic circuit 136 for supplying energy to the energy sink from the energy source and, by way of example, an evaporator 135 are arranged in the housing 130 and in an enlarged view below in 1f shown again. The electronic circuit 136 here has power electronics 136b, which is arranged here, for example, on a circuit carrier or heat sink 136a. The power electronics 136b includes in particular transistors such as IGBTs or MOSFETs, chokes, transformers, diodes, etc. The electronic circuit can be operated in particular as a converter, for example as a rectifier for converting alternating current (household current) into direct current (charging current) or as an inverter for converting direct current to alternating current.

When operating such power electronics, heat loss of more than 100 watts can occur, which should be safely dissipated. This is done by means of a heat exchanger 120b, 120c, which contains a particularly fluid working medium. In this exemplary embodiment, the lost heat is transferred, for example, into the evaporator 135, in which the working medium, for example R1234ze, is located. In particular, a wick structure 135a can be provided in the evaporator 135, which brings or conveys liquid working medium from a reservoir 135b to a side 135c which is in thermally conductive contact with the electronic circuit 136.

As in 1c and 1d shown, the electrical conductors or electrical lines 120a are arranged centrally in the cable 120, several lines being shown in the present case, but these are not relevant for understanding the present invention. In principle, only a single electrical line 120a can also be provided. This can involve the construction of a conventional electrical charging cable.

In the present case, four forward channels 120b and four return channels 120c are arranged symmetrically and alternately around the inner lines 120a, which are several here by way of example are surrounded by a shroud 120d. The outer diameter of the cable 120 can be about 1 to 4 cm.

Each forward and return channel can be formed, for example, by a polymer tube, e.g. silicone tube, with an overall diameter of, for example, about 1 mm to 5 mm and an inner diameter of, for example, about 0.2 mm to 3.5 mm, preferably from 0.5 mm to 3 mm, to achieve the compressive strength required for the specific working medium and the planned temperature. A mesh embedded in or surrounding the jacket can also be provided to provide compressive strength.

In the housing 130 , the electrical lines 120 a , which are several in this case by way of example, are connected to the electronic charging system 136 , and the outward and return channels are connected to the evaporator 135 .

A transition 110a from the forward channels 120b to the return channels 120c is arranged in the plug 110 here. This transition 110a can, for example, have a U-shape, with a forward channel 120b being connected to one leg of the U-shape and a return channel 120c being connected to the other leg of the U-shape, in particular in a fluid-conducting manner. In this case, one or more forward channels 120b can be connected to one or more return channels 120c; a star-shaped connection can also be provided, in which all forward channels 120b are connected to all return channels 120c at a star point. Of course, shapes other than a U-shape are also conceivable. The heat exchanger 120b, 120c can also be designed to be circumferential, so that the transition 110a can be, for example, the point furthest away from the evaporator 135 or the reversal point. The electrical lines 120a are connected as usual in the plug 110, for example a so-called CSS plug or a type 2 plug, with the corresponding electrical contacts.

It goes without saying that the further cable 140, not shown in detail here, can also be equipped with a heat exchanger 120b, 120c, and the connector, not shown, with a transition from the forward channels 120b to the return channels 120c. It can also be provided that only the further cable 140 has a heat exchanger 120b, 120c and not the cable 120.

During operation, i.e. for example when charging a vehicle battery using the energy supply arrangement 100 embodied as a charging cable, heat loss or waste heat Q is generated in the electronic circuit, which should advantageously be dissipated via the cable 120 . An outside temperature of the cable 120 should not be too hot, e.g. be at most 60° C., in order to avoid burns or damage.

In 1 As mentioned, the heat exchanger 120b, 120c is designed for the passage of liquid and gaseous (two-phase) working medium. The working medium in the evaporator 135 evaporates as a result of a heat flow Qv from the power converter 136, so that a pressure drop occurs along the heat exchanger 120b, 120c. The working medium is then in two phases, ie liquid and gaseous, and flows through the heat exchanger 120b, 120c, flowing away from the evaporator 135 in the feed channels 120b until it (here by way of example) passes the transition 110a in the plug 110 and again in the return channels 120c flows back to the evaporator 135. In this way, the working medium continuously gives off heat to the casing 120d and finally to the environment (heat flow Qu), with the gaseous working medium condensing. Thus, the proportion of gaseous working medium on the way through the heat exchanger decreases, in particular continuously, and the proportion of liquid working medium increases. The energy supply arrangement 100 should expediently be designed in such a way that the heat input in the evaporator 135 is equal to the heat output from the cable 120 . To improve the heat dissipation, the casing 120d can be formed with a structure that increases the surface area, for example a ribbing. If sufficient heat dissipation is not possible in certain environmental situations, for example at a very high ambient temperature, provision can be made for the power of the electronic circuit 136 to be limited (so-called derating).

In 2 is an alternative preferred embodiment of a power supply arrangement 100' in the lower part ( 2a) shown in a schematic sectional view, in which the heat exchanger 120b, 120c is designed for the passage of liquid (single-phase) working medium. above ( 2 B , 2c , 2d , 2e) The sectional view shows details of the energy supply arrangement 100' in a perspective view ( 2 B , 2d , 2e) and a cross-sectional view ( 2c ) shown.

The basic structure corresponds to that of the energy supply arrangement 100. However, in order to transport the working medium through the heat exchanger 120b, 120c, a pump 200 is provided in the housing 130. The energy supply of the pump 200 is expediently also effected here by way of example from the energy source via the cable 140 .

When executing according to 1 no pump is necessary, the transport of the working medium takes place purely passively through capillary action and pressure gradient. With a normal use of such charging cables at sockets (household or charging station), a height difference of at most 1 to 1.5 m has to be overcome, for which passive effects are sufficient.

However, it goes without saying that also in the embodiment according to FIG 1 a pump 200 may be provided to assist in transporting the two-phase working fluid.

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 3511952 A2 [0002]
• DE 102011100389 A1 [0003]

Claims (12)

Having an energy supply arrangement (100). an electronic circuit (136) for supplying energy to an energy sink from an energy source, a flexible cable (120) connected to the electronic circuit (136) for electrically connecting the electronic circuit (136) to the energy source or the energy sink, wherein the cable (120) has at least one electrical line (120a) for transmitting electrical energy and at least one heat exchanger (120b, 120c), wherein the heat exchanger (120b, 120c) contains a working medium for dissipating heat from the electronic circuit (136) into the cable (120), wherein the electronic circuit (136) is designed as a heat source and the cable (120) as a heat sink. Energy supply arrangement (100) after claim 1 , wherein the working medium in the heat exchanger (120b, 120c) is present in a gaseous and liquid mixed phase. Energy supply arrangement (100) after claim 1 or 2 , Having an evaporator (135) for the working medium, the evaporator (135) being in thermal contact with the electronic circuit (136), the evaporator (135) being in fluid communication with the heat exchanger (120b, 120c). Energy supply arrangement (100) after claim 3 , wherein the heat exchanger (120b, 120c) has at least one feed channel (120b) and at least one return channel (120c) which is fluidically connected to the feed channel and which are in fluid communication with the evaporator (135), the at least one feed channel (120b) and the at least one return passage (120c) containing the working fluid, the at least one forward passage (120b) directing the working fluid away from the evaporator (135), and the at least one return passage (120c) returning the working fluid to the evaporator (135). Energy supply arrangement (100) after claim 4 , wherein a transition from the at least one forward channel (120b) to the at least one return channel (120c) is arranged in a plug (110). Energy supply arrangement (100) after claim 4 or 5 , wherein the at least one electrical line runs closer to a central axis of the cable (120) than the at least one forward channel (120b) and the at least one return channel (120c). Energy supply arrangement (100) according to one of Claims 4 until 6 , The at least one forward channel (120b) and/or the at least one return channel (120c) directly adjoining a sheathing (120d) of the cable (120). Energy supply arrangement (100) according to any one of the preceding claims, wherein the heat exchanger (120b, 120c) is designed as a polymer tube. Energy supply arrangement (100) according to one of the preceding claims, wherein the heat exchanger (120b, 120c) is designed to be pressure-resistant up to at least 1 bar. Energy supply arrangement (100) according to one of the preceding claims, wherein the energy supply arrangement (100) has two ends, each with a plug (110). Energy supply arrangement (100) according to one of the preceding claims, wherein the working medium contains at least one refrigerant selected from organic refrigerant, R1233zd, R1234ze, R1234yf, water, ethanol, acetone, methanol, glycerol, ethylene glycol. Energy supply arrangement (100) according to any one of the preceding claims, wherein a pump (200) for pumping the working medium through the heat exchanger (120b, 120c) is provided.

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