Energy recovery unit for vehicle use

Abstract

Energy recovery unit (8) for use in a vehicle exhaust system, the energy recovery unit comprising: an inlet (24) for receiving exhaust gas from the exhaust system; an outlet (26) for returning exhaust gas to the exhaust system; several thermoelectric generators arranged between the inlet and the outlet; and a gas pipe network connected to the inlet and the outlet, the gas pipe network comprising a first line and a second line extending between the inlet and the outlet and arranged along corresponding opposite ends of the several thermoelectric generators; wherein a generator axis (T) extending perpendicular to a heat exchanger surface of at least one of the several thermoelectric generators is inclined with respect to a longitudinal axis (L) of the energy recovery unit.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an energy recovery unit for use in a vehicle exhaust system. Aspects of the invention relate to an energy recovery unit and to a vehicle exhaust system or to a vehicle in which such an energy recovery unit is integrated. STATE OF THE ART

[0002] Thermoelectric generators (TEGs) convert thermal energy into electrical energy using the Seebeck effect. A typical TEG consists of a pair of metal plates with high thermal conductivity and thermoelectric materials compressed between them.

[0003] It is known that vehicle engines operate at only about 30% efficiency and generate significant waste heat during normal use. In recent years, thermal energy generators (TEGs) have been integrated into vehicle exhaust systems to utilize waste heat from the exhaust gas. This reduces the load on an electrical generator, such as an inverter on the engine, thereby improving fuel economy.

[0004] One problem associated with using TEGs in this way is that they only function effectively over a relatively narrow temperature range. At low temperatures, energy regeneration is very inefficient, and at high temperatures, the thermoelectric materials are at risk of overheating. It has been found that in certain scenarios, the leading edge of the TEGs can overheat before the majority of the TEG has reached a sufficiently high temperature to allow for efficient operation. This means that the hot exhaust gas must be diverted away from the thermoelectric materials using bypass valves to prevent damage to the TEG, thus reducing the system's performance.

[0005] The present invention was developed to mitigate or overcome at least some of the aforementioned problems. BRIEF SUMMARY OF THE INVENTION

[0006] According to one aspect of the invention, an energy recovery unit is provided for use in a vehicle exhaust system. The energy recovery unit comprises an inlet for receiving exhaust gas from the exhaust system, an outlet for returning exhaust gas to the exhaust system, and several thermoelectric generators arranged between the inlet and the outlet. The energy recovery unit further comprises a gas pipe network configured to connect the inlet and the outlet. The gas pipe network comprises a first line and a second line, both extending between the inlet and the outlet, and arranged along corresponding opposite ends of a number of thermoelectric generators. A generator axis extending perpendicular to a heat exchanger surface of at least one of the number of thermoelectric generators is inclined with respect to a longitudinal axis of the energy recovery unit.

[0007] By tilting the generator axis, the exhaust gas flow between the inlet and outlet can be directed as desired. This allows for a more even distribution of the exhaust gas flow within the energy recovery unit, particularly in situations where the positioning and / or orientation of the inlet and / or outlet would otherwise cause the flow to concentrate in one section of the unit. This even distribution of the flow within the energy recovery unit is desirable because it ensures that each thermoelectric generator produces electrical energy at a similar level, thereby optimizing the overall energy production of the unit.

[0008] The inlet of the energy recovery system can include an inlet passage inclined relative to the central longitudinal axis of the energy recovery unit, such that the inlet passage is inclined relative to the generator axis. Similarly, the energy recovery unit can include an outlet passage inclined relative to its central longitudinal axis. The option to incline the inlet and / or outlet of an energy recovery system without significantly affecting its energy production is desirable because it allows the unit to be mounted at any point in the exhaust system.

[0009] The generator axis can be inclined opposite to the inlet passage and / or the outlet passage with respect to the central longitudinal axis.

[0010] In one embodiment, the generator axis can extend in a direction inclined relative to a direct connecting path between the inlet and the outlet, such that the generator axis extends longitudinally away from the outlet. Orienting the thermoelectric generators in this way has the particularly advantageous effect of spreading the gas, thereby increasing the energy output of the generators. This is because the guiding edges of each thermoelectric generator create vortices that cause the gas to follow a longer, indirect path to the outlet. Another advantage of this feature is a reduction in the back pressure generated in the system due to the gas spreading. This, in turn, improves engine performance.

[0011] The inlet and / or outlet can be offset transversely to the central longitudinal axis. This is particularly useful for installation situations where space within a vehicle's exhaust system is limited.

[0012] The thermoelectric generators can be arranged parallel to each other and can be spaced apart at regular intervals along the generator axis.

[0013] The energy recovery unit further comprises a valve assembly whose function is to direct exhaust gas entering the inlet between the first and second lines along each thermoelectric generator. The valve assembly thus serves to vary the flow direction of exhaust gas along each thermoelectric generator. The valve assembly can determine whether the exhaust gas flows from the first line of the gas pipeline network to the second line, or from the second line to the first line.

[0014] This is a desirable feature that helps prevent overheating of the thermoelectric generator's guide edges. Furthermore, this feature advantageously allows for a uniform heat distribution within the thermoelectric generators, ensuring a similar output level in each generator.

[0015] The generator axis can be inclined at an acute angle with respect to the central longitudinal axis of the energy recovery unit.

[0016] The opposite ends of the thermoelectric generators, along which the first and second lines extend, may be inclined with respect to the central longitudinal axis of the energy recovery unit.

[0017] The heat exchanger surfaces of the number of thermoelectric generators can extend across and / or along the energy recovery unit.

[0018] The thermoelectric generators can be arranged with their heat exchanger surfaces essentially perpendicular to the walls of the energy recovery unit, which at least partially define the first and second lines.

[0019] The opposing ends of the thermoelectric generators, along which the first and second lines extend, are optionally essentially parallel to the walls of the energy recovery unit, which at least partially define the first and second lines.

[0020] According to a further aspect of the invention, a vehicle exhaust system is provided, comprising the energy recovery unit according to one of the preceding claims.

[0021] According to another aspect of the invention, a vehicle is provided comprising the above energy recovery unit or the above vehicle exhaust system.

[0022] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives presented in the preceding paragraphs, in the claims, and / or in the following description and drawings, and in particular their individual features, may be considered independently of one another or in any combination. This means that all embodiments and / or features of any embodiment may be combined in any way and / or combination, provided that these features are not incompatible.The applicant reserves the right to amend any originally filed patent claim or to file any new patent claim accordingly, including the right to amend any originally filed patent claim to depend on and / or incorporate any feature of any other claim, even if it has not previously been claimed in this manner. List of characters

[0023] One or more embodiments of the invention will now be described exclusively by way of example with reference to the accompanying drawings; these show: Fig. 1 a schematic block diagram of a vehicle with an energy recovery unit according to an embodiment of the invention, which can be implemented in a vehicle exhaust system; Fig. 2 a transparent perspective view of an exemplary energy recovery unit with an internal TEG module; Fig. 3 a perspective exploded view of the TEG module in the energy recovery unit from Fig. 2; Fig. 4a to Fig. 4c Schematic side views of the energy recovery unit from Fig. 2 operating in different modes; and Fig. 5a to Fig. 8 transparent top views of the energy recovery unit Fig. 1 according to various embodiments of the invention. DETAILED DESCRIPTION

[0024] Fig. Figure 1 is a schematic block diagram of a vehicle. 2 , encompassing an engine 4 , which is connected to a vehicle exhaust system 6 is connected. An energy recovery unit 8 According to one embodiment of the invention, it is in the vehicle exhaust system 6integrated. The hot exhaust gas from the vehicle's exhaust system. 6 flows through the energy recovery unit 8 , before it exits the vehicle 2 is emitted. The energy recovery unit 8 It utilizes the heat energy from the exhaust gas flowing through it and converts the heat energy using thermoelectric generators (not in Fig. 1 shown).

[0025] With reference to Fig. Figure 2 shows a transparent and perspective view of an energy recovery unit. 8 It is shown. It should be noted that, for the sake of simplicity, the energy recovery unit 8 out of Fig. 2 TEG units 40 features which are arranged perpendicular to a main flow direction of exhaust gas, in contrast to embodiments according to the invention which are described below and which contain the TEG units 40exhibiting features that are inclined away from a vertical orientation. The in Fig. 2 energy recovery units shown 8 This therefore serves only to provide information in order to establish a general connection regarding the structure of such energy recovery units, before subsequently discussing the concepts and fundamentals of operation in relation to the invention.

[0026] The energy recovery unit 8 includes a TEG module 20 , surrounded by a gas pipeline network. The gas pipeline network includes an inlet in the form of an inlet pipe. 24 and an outlet in the form of an outlet pipe 26 , wherein the inlet and outlet pipes 24 , 26 at opposite ends of the energy recovery unit 8 are arranged. Two separate bypass lines 28 , 30 are above and below the TEG module 20arranged to connect the inlet and outlet pipes 24 and 26 to connect. The TEG module 20 includes several TEG units 40 , arranged parallel to each other, perpendicular to and at regular intervals along a main axis 42 of the TEG module 20 and from the adjacent or neighboring TEG unit(s) 40 spaced apart.

[0027] The energy recovery system 8 It also includes an inlet valve. 32 , arranged at the junction of the bypass lines 28 , 30 directly opposite and near the inlet pipe 24 , and an exhaust valve 34 , arranged at the junction of the bypass lines 28 , 30 directly opposite and near the outlet pipe 26 The inlet valve 32 and the exhaust valve 34 Each includes a valve flap 36 , 38, which can be rotated to change the orientation of the valves 32 , 34 to change the direction of exhaust gas flow through the energy recovery unit 8 to control, typically by directing the exhaust gas flow into and out of one of the bypass lines 28 , 30 The movement of each valve flap 36 , 38 is controlled by a corresponding valve actuator (not shown) which determines the strength and direction of the deflection of each valve flap. 36 , 38 controls the direction of the exhaust gas flow through the energy recovery unit 8 is controlled.

[0028] In some embodiments, the valve actuators can be operated independently, allowing one valve to be opened wider than another. In other embodiments, the valve actuators are operated with a single "master lever" (not shown), which allows both valves to be controlled simultaneously, so that the valve flap deflections mirror each other.

[0029] In some operating modes, the exhaust gas flows exclusively through one or both bypass lines. 28 , 30 from the inlet pipe 24 to the outlet pipe 26 , including the TEG module 20 completely bypassing and defining a main direction of the gas flow. In other operating modes, part or all of the exhaust gas flows through the TEG module in a crossflow direction that is essentially perpendicular to the main flow direction. 20A more detailed description of the energy recovery unit's operating modes 8 is below in relation to the Fig. 4a to Fig. 4c provided.

[0030] Fig. Figure 3 shows a perspective exploded view of the TEG module. 20 , which goes into the energy recovery unit 8 from Fig. 2 is included. Since Fig. 3 of the Fig. 2 corresponds, it is again pointed out that the energy recovery unit 8 shown only for contextual purposes.

[0031] The TEG module 20 includes several TEG units 40 , which are arranged parallel to each other and lie perpendicular to a plane which has a principal axis 42 of the TEG module 20 It contains the TEG units. 40 are along the main axis 42 spaced at regular intervals.

[0032] Each TEG unit 40It comprises several metal plates with high thermal conductivity and thermoelectric materials sandwiched between them, pressed together between covers made of a dielectric substrate material (such as ceramic). The outer surfaces of the dielectric covers define the heat exchange surfaces of the TEG unit. 40 - a hot-side heat exchange surface and a cold-side heat exchange surface. The hot-side heat exchange surfaces of opposing TEG units. 40 are defined by a common metal structure, which includes a metal plate in each TEG unit 40 includes structures connected by a bridge to create a structure of generally U-shaped cross-section.

[0033] The TEG units 40 are arranged during use such that the main heat exchange surfaces are essentially perpendicular to the main axis 42 of the TEG module 20 lie, with the TEG units 40are arranged in such a way that the hot-side heat exchange surface of each TEG unit 40 the hot-side heat exchange surface of a TEG unit facing it 40 is turned towards.

[0034] The TEG module 20 further includes a coolant pipe arrangement 43 The coolant pipe arrangement 43 includes several U-current coolant pipes 44 with an inlet end and an outlet end, wherein both the inlet end and the outlet end are at the same end of each U-flow coolant tube 44 are arranged, with one positioned vertically above the other. The coolant fluid in each U-flow coolant tube 44 Thus, it flows from the inlet in one direction into the U-flow coolant pipe. 44 and in the opposite direction towards the outlet and out of the U-flow coolant pipe 44 out. The multiple U-current coolant pipes 44are inserted into the TEG module at intervals. 20 inserted that each U-current coolant pipe 44 between each pair of cold-side heat exchange surfaces of opposing TEG units 40 and in essentially parallel alignment to this and adjacent to the outward-facing cold-side heat exchange surfaces of the TEG units 40 at each end of the TEG module 20 is arranged. Each U-flow coolant pipe 44 is arranged such that the section of the pipe into which the coolant fluid flows from the inlet is essentially parallel to the cold-side heat exchange surface of the associated TEG unit 40 and extends into contact with it.

[0035] The TEG module 20 further includes a pair of parallel metal plates that are essentially parallel to the hot-side heat exchange surface of each TEG unit 40extend and are in contact with it. These plates create a series of channels that serve as exhaust outlets. 46 define, through which the exhaust gas passes through the TEG module 20 can flow.

[0036] Several wedges 48 are integrated into the TEG module 20 introduced to provide separate coolant U-tubes for 44 adjacent TEG units 40 to separate them. A tension band 50 extends to the scope of the TEG module 20 around, coplanar with the main axis 42 , along which the components of the TEG module 20 are arranged. The TEG module 20 is furthermore equipped with a pair of bridge-like end buffers 52 provided at both ends of the main axis of the TEG module 20 are arranged. After installation, the wedges remain. 48 in the TEG module 20 in installed position to ensure that the coolant pipes 44remain firmly in the installed position.

[0037] According to this, in the Fig. The main components of the TEG module arrangement shown in Figure 3 are provided in the following order: coolant U-tube 44, TEG unit 40 , exhaust gas passage 46 , TEG unit 40 , Coolant U-pipe 44, wedge 48 , Coolant U-tube 44, TEG unit 40 , exhaust gas passage 46 , TEG unit 40 , Coolant U-pipe 44, wedge 48 and so forth.

[0038] During use, hot exhaust gas is expelled through the exhaust vents. 46 of the TEG module 20 This increases the temperature of the hot-side heat exchange surfaces. Meanwhile, cooling fluid (e.g., water) is circulated through the coolant pipe arrangement. 43 of the TEG module 20 Directed to maintain the temperatures of the cold-side heat exchange surfaces. This creates the required temperature gradient along each TEG unit.40 to generate energy. The use of cooling fluid maximizes the temperature gradient and thus the electrical output of each TEG unit.

[0039] In some embodiments, convector lamellae can 53 , as can be found in conventional convection radiators, from each hot-side heat exchange surface into the exhaust gas passages 46 extend into it. The presence of convector lamellae. 53 increases the surface area of ​​thermally conductive material in contact with the hot exhaust gas, thereby improving heat transfer to the hot-side heat exchanger surfaces along the exhaust gas passages. 46 is increased.

[0040] Various measures are taken to ensure that the cold-side heat exchange surfaces are kept in close contact with the coolant U-tubes 44 for maximum heat transfer. For example, as mentioned previously, wedges are used. 48inserted between adjacent coolant U-tubes 44. The tension band 50 Furthermore, it generates an inward-directed clamping force on the components of the TEG module. 20 and the end buffers 52 The effects of this clamping force are spread more evenly across the cross-section of the TEG module. 20 to prevent warping or deformation of the component due to uneven pressure.

[0041] It is noted that all directional references herein, such as "left", "right", "top", "bottom", "vertical", and "horizontal", are made in relation to the embodiments shown in the accompanying figures. However, it is noted that the energy recovery unit and its components may be arranged and installed in other orientations than those shown in the attached figures, and that such arrangements are to be considered to fall within the scope of the present invention, as defined in the accompanying claims.

[0042] Fig. 4a to Fig. Figure 4c shows schematic side views of the energy recovery unit. 8 out of Fig. 2 and they show different operating modes of the energy recovery unit 8 Although this refers to the energy recovery unit 8 from the Fig. 2 and Fig. With reference to Figure 3, which, as already mentioned, differs from energy recovery units according to the invention and is only shown to establish a connection, those skilled in the art will recognize that the principles and operating modes discussed below are applicable to energy recovery units according to the invention, such as those described below with reference to the Fig. 5a to Fig. 8 will be described.

[0043] Each operating mode is associated with a different configuration of the inlet and outlet valves. 32 , 34 connected. In particular, each operating mode is determined by the relative proportions of the exhaust gas passing through the TEG module. 20 and through the bypass lines 28 , 30 flows, which are determined by the value by which each valve flap 36 , 38is deflected with respect to the main flow direction of the exhaust gas, and is defined by the directions in which the deflections occur. There are three main operating modes – a “bypass mode”, illustrated in Fig. 4a; a “full-current mode”, depicted in Fig. 4b; and a “sailing mode”, illustrated in Fig. 4c.

[0044] In bypass mode, neither the intake valve flap 36 still the exhaust valve flap 38 They are particularly deflected, remaining essentially parallel to the main flow direction of the exhaust gas. This allows the exhaust gas to pass unimpeded from the inlet pipe. 24 on both sides of the intake valve 32 past into the bypass lines 28 , 30 flows, then at the outlet valve 34 flows past and then the energy recovery unit 8 through the outlet pipe 26 leaves without even entering the TEG module 20 to enter.

[0045] It is noted that the exhaust gas does not change direction to enter an exhaust passage. 46 of the TEG module 20 to enter, unless there is significant flow resistance along the bypass lines 28 , 30 Therefore, in bypass mode, essentially all the exhaust gas flows through the bypass lines. 28 , 30 .

[0046] The energy recovery unit 8 It operates in bypass mode when the TEG module 20 There is a risk of overheating. This can happen, for example, if the exhaust gas entering the energy recovery unit... 8 occurs, has too high a temperature, or if the exhaust gas passes through the TEG module for an extended period of time. 20 flows.

[0047] In full-flow mode, the intake valve flap 36 and the exhaust valve flap 38deflected maximally in opposite directions, each completely passing over an opening of another of the bypass lines 28 , 30 This prevents the gas flow from the energy recovery unit from passing through the same bypass line. 8 exit through which it entered, and thus the entire exhaust gas passes through the TEG module. 20 crowded, as there is no direct path through the bypass lines 28 , 30 from the inlet pipe 24 to the outlet pipe 26 for which the gas is available.

[0048] For example, as shown in the top view in Fig. 4b shows the inlet valve flap. 36 deflected downwards as much as possible, causing the exhaust gas to flow completely into the lower bypass line. 30 flows; however, if the exhaust valve flap 38is deflected upwards to the maximum extent, so that the exhaust gas does not exit directly from the upper bypass line. 30 through the outlet pipe 26 from the energy recovery unit 8 escape. Instead, the exhaust gas is routed from the upper bypass line. 30 through the exhaust vents 46 of the TEG module 20 and into the lower bypass line 28 pushed around the outlet pipe 26 to achieve this. The direction of the transverse flow through the gas passages. 46 of the TEG module 20 This can be reversed by changing the direction of deflection of the intake and exhaust valve flaps. 36 , 38 (as indicated by the dotted lines in Fig. 4b) is reversed.

[0049] As a result of efficient heat exchange between the exhaust gas and the metal plates of the TEG units 40and the electrical energy generated from this heat significantly cools the exhaust gas as it passes through the exhaust passage 46 It flows. Accordingly, the guiding edges of each TEG unit heat up. 40 much faster than the rest of the unit.

[0050] In one embodiment according to the invention, the direction of deflection of the valve flaps is 36 , 38 and therefore also the direction of the transverse flow through the exhaust vents 46 of the TEG module 20 The rotation is reversed periodically. This prevents the guide edges of the TEG module from overheating. 20 , which extends its lifespan.

[0051] The output of the energy recovery unit 8This is also increased because the alternating flow creates a more uniform temperature profile along each hot-side heat exchanger surface than is achieved with a single-directional flow. This means that the bypass mode is used less frequently and that a larger proportion of the TEG module is used. 20 It is used to generate electricity.

[0052] In sailing mode, shown in Fig. 4c, the intake and exhaust valve flaps 36 , 38 deflected to varying degrees, while none of the bypass lines 28 , 30 is completely closed. Therefore, in bypass mode, essentially all of the exhaust gas flows through the bypass lines. 28 , 30 , but it provides sufficient resistance to direct some of the exhaust gas into the TEG module 20to push. The sailing mode can therefore be seen as a combination of the bypass mode and the full-flow mode.

[0053] For example, as in the Fig. 4c shows the intake valve flap. 36 deflected maximally downwards, while the outlet valve flap 38 essentially remains parallel to the main flow direction. Therefore, exhaust gas flows along one of two paths: the first path corresponds to direct flow from the inlet pipe. 24 to the outlet pipe 26 through the upper bypass line 30 ; the second path corresponds to a flow from the upper bypass line 30 through the gas passages 46 of the TEG module 20 into the lower bypass line 28 and into the outlet pipe 26 .

[0054] The degree and direction of deflection of the exhaust valve flap 38can be varied depending on the proportion of gas (as shown by the dotted line in Fig. 4c indicated), which through the gas passages 46 of the TEG module 20 It should flow. A greater deflection of the exhaust valve flap. 38 up in Fig. 4c results in a larger proportion of gas passing through the TEG module. 20 flows.

[0055] This mode is useful for ensuring that at high gas temperatures, the amount of exhaust gas passing through the TEG module is controlled. 20 flows (and thus the amount of heat supplied to each TEG unit) 40 ) through the cooling capacities of the cooling pipe arrangement 43 is supported.

[0056] Although specific valve deflections in the Fig. 4a to Fig. As shown in Figure 4c, it is pointed out that the functionality of the energy recovery unit 8would not be significantly affected if the deflections of the intake valve flap 36 and the exhaust valve flap 38 The opposite is true to the depicted state. For example, in sailing mode, it is sufficient that only one of the valve flaps is open. 36 , 38 is deflected to a maximum extent in a specific direction, provided that the deflection angle of the other valve flap remains variable to regulate the amount of exhaust gas passing through the TEG module 20 flows.

[0057] It is noted that the presence of independently operable valves would be a useful feature in embodiments where the energy recovery unit operates in sail mode, as this would allow precise control of each valve flap. In contrast, the presence of a "master lever" would be a useful addition in embodiments where the energy recovery unit operates in bypass or full-flow mode, since the degree of deflection of the two valve flaps would ideally mirror each other. Using the master lever to automate valve deflections would be particularly useful when a periodically alternating flow is required.

[0058] It should be noted at this point that the previously described energy recovery units provide a basis for the present invention, which can alternatively be used with other types of units, such as units with only one bypass line. It should be noted that the previously mentioned energy recovery units are related to the present invention. Fig. 2 to Fig. The four concepts discussed are applicable and adaptable in order to be used in conjunction with the following with reference to the Fig. 5a to Fig. to be used in the embodiments of the invention described in section 8.

[0059] The Fig. 5a and Fig. Figure 5b shows complementary embodiments of the invention, which are mirror images of each other. As will be evident from the following description, embodiments of the invention provide energy recovery units with inlet and outlet pipes that are offset from a longitudinal axis of the unit and / or angled with respect to the central axis. These arrangements increase the flexibility with regard to energy recovery units in a vehicle environment. For example, these features make it possible to install an energy recovery unit near a bend in the exhaust system and thus to make effective use of the available space.

[0060] However, configuring the inlet and / or outlet in this way affects the direction of the exhaust gas flow into and through the energy recovery unit, which can lead to a non-uniform flow distribution. This, in turn, results in a non-uniform heat flow along each TEG unit within the energy recovery unit, thus reducing the energy recovery efficiency. It should be noted that for optimized energy recovery, a uniform flow through each exhaust gas passage is required so that each TEG unit experiences the same heat flow, with this flow being evenly distributed across the hot-side heat exchange surface of the TEG unit.

[0061] To counteract the uneven flow distribution that could otherwise be generated by tilting or offsetting the inlet or outlet, embodiments according to the invention provide TEG modules in which the TEG units are not arranged perpendicular to a longitudinal axis of the energy recovery unit; rather, the TEG units are oriented diagonally. As will be discussed, this configuration directs the exhaust gas flow in a desired direction to improve the flow distribution in the energy recovery unit.

[0062] This configuration also provides an improved advantage by allowing the TEG unit to be screwed onto adjacent units, while in the Fig. 2 and Fig. In the module shown in Figure 3, where all TEGs are aligned, a single screw is typically used to couple all TEG units together. The relative thermal expansion of adjacent units is less than the relative thermal expansion of the first and last units, and thus the ability to couple adjacent units together results in lower thermal stresses in the module during use than would be the case if the modules were coupled in a single direction. 2 and 3 The clamp discussed would have been used.

[0063] Taking into account the factors in the Fig. 5a and Fig. The embodiments shown in 5b are in particular similar to the energy recovery unit. 8 from the Fig. 2 to Fig. 4 an energy recovery unit 100 ready to use a TEG module 102It comprises a structure surrounded by a gas pipeline network. The gas pipeline network includes an inlet in the form of an inlet pipe. 104 and an outlet in the form of an outlet pipe 106 , wherein the inlet and outlet are located at opposite ends of the energy recovery unit 100 are arranged. Two separate bypass lines (in the Fig. 5a and Fig. 5b (not shown) are above and below the TEG module 102 arranged, enclosed by exterior walls (also in the Fig. 5a and Fig. 5b not shown) of the energy recovery unit 100 , to the inlet and outlet pipe 104 and 106 to connect.

[0064] The inlet pipe 104 and the outlet pipe 106are oriented at an acute angle to the bypass lines. Therefore, the direction in which the gas flows longitudinally through the unit's bypass lines varies, and thus there is no identifiable coherent main flow direction, as is the case in the Fig. The arrangement shown in point 2 is not the case. Therefore, in the following description, a central longitudinal axis L of the energy recovery unit should be used instead. 100 can be used as a reference point. As in Fig. As can be seen in 5a, the longitudinal axis L extends longitudinally through the energy recovery unit. 100 between one end of the unit 100 , the inlet pipe 104 contains, and an end that is the outlet pipe 106 contains, and it is located in the transverse direction midway between opposite sides of the energy recovery unit 100 arranged.

[0065] In contrast to the arrangement from Fig. 2 are in the in the Fig. 5a and Fig. In embodiments 5b shown, the inlet and outlet pipes 104 , 106 from the longitudinal axis L of the unit 100 staggered, with each pipe 104 , 106 is offset to one side of the central longitudinal axis L, so that the inlet and outlet pipes 104 , 106 are almost aligned with each other, although they are aligned with respect to the central longitudinal axis L of the energy recovery unit 100 are inclined.

[0066] The energy recovery system 100 It also includes an inlet valve. 108 , arranged at the junction 110 the bypass lines directly opposite and near the inlet pipe 104 , and an exhaust valve 112 , arranged at the junction 114 the bypass lines directly opposite and near the outlet pipe 106 The inlet valve 108and the exhaust valve 112 Each includes a valve flap 116 , 118 , which can be rotated to change the orientation of the valves 110 , 112 to change the direction of exhaust gas flow through the energy recovery unit 100 to control, typically by directing the exhaust flow in and out of one of the bypass lines. The movement of each valve flap 116 , 118 is provided by a corresponding valve actuator 120 , 122 controlled, which determines the strength and direction of the deflection of each valve flap. 116 , 118 controls the direction of the exhaust gas flow through the energy recovery unit 100 is controlled.

[0067] The intake and exhaust valve flaps 116 and 118 are also related to the longitudinal axis L of the energy recovery unit 100angled. This means the angle at which gas predominantly passes through the valve flaps. 116 , 118 flows, is not on the longitudinal axis L of the energy recovery unit 100 The valve flaps are trapezoidal in shape and are hinged to rotate about a shaft located on an axis situated at or near a midpoint between the leading edge and the trailing edge of each flap. 116 , 118 is located.

[0068] The TEG module 102 It is located between the bypass lines and includes several combinations. 124 from TEG units 125 , wedges and coolant U-tubes of different lengths arranged parallel to each other, so that the heat exchanger surfaces of the TEG units 125 essentially perpendicular to the outer walls of the TEG module 102 are some of which define the bypass lines. The combinations124 from TEG unit 125 The wedge and coolant U-tube are spaced at regular intervals along the TEG axis T to accommodate multiple exhaust gas passages. 126 to define. The bypass lines extend along corresponding opposite ends of the TEG units. 125 , so that the gas passages 126 communication between the bypass lines in directions as shown in the diagram of the Fig. 5a and Fig. 5b in and out of this one.

[0069] The TEG units 125 are parallel to corresponding planes of the opposing outer walls of the energy recovery unit 100 oriented, which partly define the bypass lines, so that the bypass lines have an essentially uniform cross-section along the longitudinal axis.

[0070] The TEG axis T lies perpendicular to the heat exchanger surfaces of each TEG unit.125 and it is in relation to the central longitudinal axis of the energy recovery unit 100 inclined at an acute angle. As a result, the opposite ends of the TEG units are 125 , along which the bypass lines extend and the guide edges 128 the TEG units 125 Define, inclined with respect to the longitudinal axis L. This means that the TEG units 125 both across and along the energy recovery unit 100 extend.

[0071] It is pointed out that the TEG axis T and the corresponding axes I, O of the inlet and / or outlet pipe 104 , 106 in opposite directions with respect to the longitudinal axis L of the energy recovery unit 100 are angled so that the TEG units 125 almost parallel to the axes I, O of the inlet and outlet pipes 104 ,106 This means the angle between the TEG axis T and the axis I, O of the inlet pipe or the outlet pipe. 104 , 106 at least as large as the angle between the longitudinal axis L of the energy recovery unit 100 and the TEG axis T or between the longitudinal axis L of the energy recovery unit 100 and the axis I, O of an inlet or outlet pipe 104 , 106 .

[0072] In use, the valve flaps 116 , 118 in accordance with the schematic diagrams in the Fig. 4a to Fig. 4c activated. In full-current mode, the current flows, which is in Fig. In accordance with the valve configuration shown in 4b, all hot exhaust gas passes through the angled exhaust ports. 126 .

[0073] At this point, it is pointed out that exhaust gas coming from the intake pipe 104The flow does not change direction as long as no external force acts upon it. Since the inlet pipe 104 with respect to the longitudinal axis L of the energy recovery unit 100 Since it is inclined and offset from this, exhaust gas flows out of the inlet pipe. 104 exits, generally diagonally across the TEG module 102 and almost directly towards the outlet pipe 106 unless this flow is diverted from this path. If not diverted, the majority of the exhaust gas would only pass over one side of the TEG module. 102 flow, which leads to poor heat distribution in the TEG module 102 and would therefore lead to inefficient energy production. For example, in the Fig. In the embodiment shown in Figure 5a, the exhaust gas flows mainly along the left side, as can be seen in the figure, unless the gas is redirected.

[0074] For this reason, the TEG units125 angled as in the embodiments of the Fig. 5a and Fig. 5b shown. As will be explained below, by orienting the TEG units 125 almost parallel to the angle at which exhaust gas enters the energy recovery unit 100 The exhaust gas flows more evenly along the TEG module. 102 They are redirected and redistributed. This allows for more effective recovery of thermal energy from these gases.

[0075] First, it should be noted that the guiding edges 128 the TEG units 125 Creating vortices as exhaust gases flow over them. The generation of vortices at the guide edges. 128 This creates low-pressure areas just below these edges. The resulting pressure differential causes gas to flow along the guide edges. 128 and into the corresponding exhaust vents 126to suck. The sequence of vortices passing through the series of TEG units. 125 of the TEG module 102 The resulting effect is that exhaust gas flows towards the area from the inlet. 104 furthest TEG unit 127 is sucked in. If a sufficiently large number of TEG units are present. 125 If this condition is present, it ultimately leads to the exhaust gas flow being redirected until it is aligned with the TEG axis T.

[0076] In this way, the orientation of the TEG units is affected. 125 the path the exhaust gas takes through the bypass lines. Thus, the angle at which the TEG units operate can be determined. 125 are oriented to ensure optimized heat distribution through the energy recovery unit 100 to provide and to maximize the generation of electrical energy.

[0077] By angling the TEG units 125with respect to a longitudinal axis L of the energy recovery unit 100 , which results in the furthest TEG unit 127 in a corner of the energy recovery unit 100 is arranged next to the outlet pipe 106 The effects of the TEG units are felt. 125 generated vortices to direct the exhaust flow from the outlet pipe 106 to redirect the exhaust gas. This distributes the exhaust gas more evenly across the TEG module. 102 This improves heat flow through the bypass lines in full-flow mode, thus increasing the efficiency of the energy recovery unit. 100 compared to a module like the one in Fig. 2 shown, in which the TEG units 40 are oriented perpendicular to the longitudinal axis L, improved.

[0078] In other embodiments, under certain circumstances, energy recovery units with both inlet and outlet pipes extending substantially parallel to the central longitudinal axis of the unit, and an angled TEG module, benefit from a TEG axis inclined with respect to the longitudinal axis to direct the gas flow away from the outlet pipe, as in the embodiments described above. For example, if the inlet and outlet pipes are opposite each other and offset from the central axis of the unit, an angled TEG axis prevents gas from flowing exclusively on one side of the unit between the inlet and outlet pipes, which would result in poor energy recovery. In this example, as in other embodiments, the TEG unit is angled to direct gas away from the corner of the TEG module closest to the outlet pipe and toward the opposite side of the TEG module.This effectively causes gas to flow away from the outlet, resulting in a longer path for the gas to reach the outlet and thus spreading more effectively within the TEG module. This, in turn, improves gas distribution and reduces backpressure within the system, thereby minimizing the impact of the TEG module on engine performance.

[0079] The Fig. 6a and Fig. 6b and the Fig. 7a and Fig. Figure 7b shows parts of complementary mirror-symmetric energy recovery units. 200 , 300 according to corresponding embodiments of the invention. Each of these four embodiments relates to an energy recovery unit with only one angled inlet or outlet pipe. In the Fig. 6a and Fig. 6b Energy recovery units with an angled outlet pipe 204 and a straight inlet pipe 202shown while in the Fig. 7a and Fig. 7b Energy recovery units 300 with an angled inlet pipe 302 , but with a straight outlet pipe 304 be shown.

[0080] Apart from modified configurations of the intake and exhaust pipes, the following are also included in the Fig. 6a to Fig. Energy recovery units shown in 7b 200 , 300 generally identical to those previously mentioned with reference to the Fig. 5a and Fig. 5b described. In particular, it is pointed out that, as for the embodiments of the Fig. 5a and Fig. 5b shown, in the in the Fig. 6a to Fig. In the energy recovery units shown in Figure 7b, the angle of the TEG axis with respect to the inlet or outlet pipe is at least as large as the angle between the longitudinal axis of the energy recovery unit and either axis. It is intended that the angle of the TEG axis with respect to the inlet or outlet pipe is typically between 30 and 70 degrees. An angle of this magnitude generates a beneficial vortex at the inlet edge of each TEG unit, thereby improving the flow distribution within the energy recovery unit.

[0081] Furthermore, in each embodiment, the TEG axis is oriented away from the outlet such that the TEG unit furthest from the inlet pipe is located in a corner of the energy recovery unit adjacent to a corner closest to the outlet pipe. In other words, the TEG axis is inclined with respect to a hypothetical direct straight path between the inlet pipe and the outlet pipe. As in the embodiments described above, this configuration ensures that exhaust gas is drawn away from the outlet pipe as it flows through the bypass lines and is thus effectively distributed through the TEG module for optimized energy recovery.

[0082] Fig. Figure 8 shows an alternative embodiment of an energy recovery unit 400 , which, similar to previous embodiments, has an inlet pipe 402 and an outlet pipe 404with axes I, O, which are in relation to the central longitudinal axis L of the unit 400 are inclined. Unlike in the embodiments above, the unit contains 400 a TEG module 102 , within the unit 400 is arranged so that its TEG units 125 on a TEG axis T which is inclined in the same direction as the inlet / outlet axes I, O with respect to the central longitudinal axis L; in the embodiments described above, the TEG axis T and the inlet / outlet axes I, O were inclined in opposite directions with respect to the central longitudinal axis L.

[0083] Configuring the TEG module 102 in this way with regard to the inlet pipe 402 and the outlet pipe 404 represents an alternative way to control the flow distribution within the energy recovery unit 400to improve. Due to the small angle between the TEG axis T and the inlet axis I, a vortex is formed along the inlet, which causes the flow to be deflected from the path it normally takes through the unit. 400 along the TEG units 125 would take this, which results in the exhaust gas taking an indirect path to the exhaust pipe. 404 takes. As in the embodiments above, this improves energy recovery by distributing heat more evenly across the TEG module. 102 is distributed.

[0084] In further embodiments, it is conceivable that an inlet and an outlet are oriented in opposite directions; in this case, the TEG axis T would lie in a direction opposite to the angle of the inlet pipe.

[0085] Although the in the Fig. 5a to Fig.Although the figures shown in Figure 8 are only top views, it should be noted that the angling of the inlet and outlet pipes in each embodiment need not be limited to a single plane. Rather, in certain situations it would be advantageous to arrange an inlet pipe at an acute angle in two planes with respect to the longitudinal axis of the energy recovery unit.

[0086] Numerous modifications can be made to the above examples without deviating from the scope of the present invention as defined in the attached claims.

Claims

[1] Energy recovery unit for use in a vehicle exhaust system, the energy recovery unit comprising: an inlet for receiving exhaust gas from the exhaust system; an outlet for returning exhaust gas to the exhaust system; several thermoelectric generators arranged between the inlet and the outlet; and a gas pipe network connected to the inlet and outlet, wherein the gas pipe network comprises a first line and a second line extending between the inlet and the outlet and arranged along corresponding opposite ends of the multiple thermoelectric generators; wherein a generator axis (T) extending perpendicular to a heat exchanger surface of at least one of the multiple thermoelectric generators is inclined with respect to a longitudinal axis (L) of the energy recovery unit. [2] Energy recovery unit according to claim 1, wherein the inlet comprises an inlet passage which is inclined with respect to the central longitudinal axis (L) of the energy recovery unit, such that the inlet passage is inclined with respect to the generator axis (T). [3] Energy recovery unit according to claim 2, wherein the generator axis (T) is inclined opposite to the inlet passage with respect to the central longitudinal axis (L). [4] Energy recovery unit according to one of the preceding claims, wherein the outlet comprises an outlet passage inclined with respect to the central longitudinal axis (L) of the energy recovery unit. [5] Energy recovery unit according to claim 4, wherein the generator axis (T) is inclined opposite to the outlet passage with respect to the central longitudinal axis (L). [6] Energy recovery unit according to any of the preceding claims, wherein the generator axis (T) extends in a direction inclined with respect to a direct connecting path between the inlet and the outlet. [7] Energy recovery unit according to one of the preceding claims, wherein the inlet and / or the outlet is offset transversely to the central longitudinal axis (L). [8] Energy recovery unit according to one of the preceding claims, wherein the thermoelectric generators are arranged parallel to each other. [9] Energy recovery unit according to one of the preceding claims, wherein the thermoelectric generators are spaced apart at regular intervals along the generator axis (T). [10] Energy recovery unit according to one of the preceding claims, further comprising a valve arrangement having the function of directing exhaust gas entering the inlet between the first and the second inlet along each thermoelectric generator, wherein the valve arrangement has the function of varying the flow direction of exhaust gas along each thermoelectric generator. [11] Energy recovery unit according to claim 10, wherein the valve arrangement has the function of determining whether the exhaust gas flows from the first line of the gas pipe network to the second line, or from the second line to the first line. [12] Energy recovery unit according to one of the preceding claims, wherein the generator axis is inclined at an acute angle with respect to the central longitudinal axis (L) of the energy recovery unit. [13] Energy recovery unit according to one of the preceding claims, wherein the opposite ends of the thermoelectric generators, along which the first and second lines extend, are inclined with respect to the central longitudinal axis (L) of the energy recovery unit. [14] Energy recovery unit according to one of the preceding claims, wherein the heat exchanger surfaces of the number of thermoelectric generators extend transversely along the energy recovery unit. [15] Energy recovery unit according to one of the preceding claims, wherein the heat exchanger surfaces of the number of thermoelectric generators extend longitudinally along the energy recovery unit. [16] Energy recovery unit according to one of the preceding claims, wherein the thermoelectric generators with their heat exchanger surfaces are arranged substantially perpendicular to walls of the energy recovery unit which define at least partially the first and the second line. [17] Energy recovery unit according to one of the preceding claims, wherein the opposite ends of the thermoelectric generators, along which the first and second lines extend, are substantially parallel to walls of the energy recovery unit which define at least partially the first and second lines. [18] Vehicle exhaust system comprising the energy recovery unit according to any of the preceding claims. [19] Vehicle comprising the vehicle exhaust system according to any one of claims 1 to 17 or the vehicle exhaust system according to claim 18.

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