Defrosting system in an electric vehicle for a heat pump

Abstract

In order to create a de-icing system (100) in an electric vehicle (29) for a heat pump, which can eliminate icing without damaging any vehicle components and increases the efficiency of a heat pump affected by icing, it is proposed that the de-icing system (100) includes at least one de-icing device (10) and at least one defrost water drain (11).

Description

[0001] The invention relates to a de-icing system in an electric vehicle for a heat pump, a method for operating the de-icing system and a vehicle comprising such a de-icing system.

[0002] DE 10 2020 112 293 A1 describes a heat exchanger for a heat pump, in particular for air conditioning a vehicle interior, comprising a plurality of parallel pipes for conveying a refrigerant, wherein fins are arranged between the pipes which are thermally coupled to the pipes.

[0003] From DE 10 2020 200 079 A1, an outdoor air heat exchanger for a vehicle is known. It is provided that a manifold of the outdoor air heat exchanger is equipped with capillaries so that capillary action assists in the removal of water.

[0004] German patent DE 10 2018 131 026 A1 relates to a heat exchanger for a vehicle, in particular an electric vehicle. The patent provides a heat exchanger for a vehicle, specifically an electric vehicle. Such a heat exchanger comprises at least a first hollow body containing a first medium. A cooling device with at least one finned element is also provided. The cooling device is designed to be permeated by a second medium and is attached to the first hollow body by means of a mounting area of ​​the finned element, enabling energy transfer between the first and second media. The mounting area is enclosed by two side walls of the finned element.It is provided that the fastening area of ​​the at least one lamella body is aligned parallel to a plane of a longitudinal side of the at least one first hollow body which faces the lamella body, and that the two respective side walls are aligned at an angle between 75° and 105° to a surface of the at least one first hollow body which faces the lamella body.

[0005] DE 10 2021 211 228 A1 relates to a heat exchanger, in particular an evaporator, with a tube-fin block comprising tubes and fin elements, wherein the tubes are spaced apart in a row or in rows and arranged parallel to each other, wherein fin elements are arranged between the tubes, extending between each pair of adjacent tubes, wherein at least one collection box is provided, wherein the tube ends of the tubes of the tube-fin block are inserted into openings of the at least one collection box, wherein a drainage conveying element is provided on one of the collection boxes, which is arranged in certain areas at a defined distance from the collection box and has lugs that engage between the tubes to create at least one drainage channel between the surface of the collection box and the drainage conveying element.which facilitates the removal of a quantity of water collected on the surface of the collection box.

[0006] Ensuring passenger comfort in battery-electric vehicles (EVs) presents an energy challenge. While the energy for heating in cold weather can be supplied by a primary energy source, this reduces the vehicle's range.

[0007] Heat pumps can compensate for heating requirements more efficiently. Typically, energy is extracted from the environment via a heat exchanger. This energy extraction can lead to icing of the heat exchanger, which can restrict its use. During defrosting, the resulting condensate must be removed.

[0008] The invention is based on the objective of proposing a de-icing system by which icing can be remedied in such a way that no vehicle components are damaged and the efficiency of a heat pump affected by icing is increased by de-icing.

[0009] This problem is solved by the de-icing system claimed in claim 1.

[0010] Further advantageous embodiments of the invention are described in the dependent claims.

[0011] According to the invention, a de-icing system is provided in an electric vehicle for a heat pump, wherein the de-icing system comprises at least one de-icing device and at least one defrost water drain.

[0012] The expert uses the terms battery-electric vehicle, electric vehicle, and / or electric hybrid vehicle synonymously. The advantage of the de-icing system is that if a heat exchanger, heat pump, and / or defrost drain ices up, de-icing and drainage of the resulting defrost water can be carried out efficiently to restore full functionality. If the icing were to persist, it would lead to long-term damage to the components of the electric vehicle surrounding the ice. The de-icing system is particularly advantageous in climates where defrost drains frequently freeze and occur with increased intensity. Another advantage is that the defrost water is drained away directly, thus reducing the likelihood of re-icing immediately after the de-icing system is switched off.

[0013] For example, at least one defrost water drain can be located in a primary and / or secondary cooling air path of the vehicle. Under normal and / or elevated humidity conditions, water can condense on cold surfaces and, depending on the temperature, freeze. When this water thaws, it must be drained away from the affected component to prevent re-icing or build-up of ice. Therefore, locating the defrost water drain in the primary cooling air path is advantageous.

[0014] For example, the first cooling air path is formed between a primary cooler and a fan. This prevents the fan from icing up, as it can freeze solid, or the blades can be damaged by ice buildup.

[0015] For example, the second cooling air path is located between the first radiator and a second radiator. Additional cooling air paths enable the efficient cooling of other components of the electric vehicle. Condensation is also advantageously drained away via the defrost drain in this second cooling air path.

[0016] For example, the first cooler is a gas cooler. Gas coolers are advantageously used in heat pump systems that, for instance, use CO2 refrigerant. In these systems, the refrigerant operates partially above its critical point, meaning it is no longer in the classic gas or liquid phase, but in a supercritical state. The gas cooler ensures that the refrigerant is cooled. This makes the gas cooler particularly susceptible to ice formation.

[0017] For example, the second cooler is a low-temperature cooler. The low-temperature cooler is part of a cooling circuit in an electric vehicle and dissipates excess heat from a battery, power electronics, and / or the heat pump.

[0018] For example, the defrost water drain comprises at least one opening, wherein the opening is directed towards the underbody of the vehicle, and wherein the opening has a rectangular, oval, and / or round shape. Preferably, the defrost water drain comprises at least two openings, and more preferably at least three openings. The openings can be arranged, for example, parallel, in a row, and / or as a grid. In particular, the shape of the openings enables the efficient drainage of defrost water. For example, the opening can be arranged perpendicular to the direction of travel of the vehicle, wherein the width of the opening is more than 50%, and preferably more than 75%, of the total width of the first and / or second cooling air path. This allows the defrost water accumulating across the entire width of the cooling air path to be efficiently drained through the corresponding opening.For example, opposite ends of the opening are angled relative to each other; preferably, the angle of a first end, located in the direction of travel of the electric vehicle, is at least 20° relative to the end located opposite the direction of travel of the electric vehicle. This creates a suction effect during driving, which draws any defrost water out of the opening by forming a negative pressure.

[0019] For example, the defrosting device is designed as an electric heating element, which is positioned between the first cooler and the fan. This accelerates the defrosting process and / or enables it to function at ambient temperatures below 0 °C. The electric heating element can, for example, be positively connected to the first cooler and the fan. This ensures that the heat generated by the heating element is transferred to the relevant components as efficiently as possible, without any intervening air acting as insulation. The electric heating element could, for example, be a heating mat.

[0020] For example, the voltage of the electric heating element is 12 V or more, preferably more than 48 V, and is connected to the vehicle's electrical system. This has the advantage that the vehicle's existing infrastructure can be used for the electric heating element, thus offering a potential for cost savings.

[0021] For example, the electric heating element is part of a charging device for an electric vehicle battery. This offers the advantage that heat generated by charging the electric vehicle's battery can be used directly via the electric heating element to defrost ice.

[0022] For example, the de-icing device can be designed as an alternative or additional component, a heated refrigerant line. This would allow existing vehicle infrastructure to be used for de-icing. The refrigerant line is partially heated and / or warmed up within a heat pump and can thus contribute to de-icing through appropriate configuration. This also creates an additional cooling surface area. "Heated" in this context means that the temperature is suitable for melting ice. Preferably, the temperature of the heated refrigerant line is at least 10 °C, more preferably at least 20 °C, and most preferably at least 25 °C.

[0023] For example, the refrigerant line is designed as a round tube and / or an extruded profile. Advantageously, the extruded profile can be oval. An oval shape, in particular, has the advantage that it can be positioned above the opening in such a way that, for example, the resulting slot can be optimally defrosted by positioning the extruded profile at a distance from the opening, allowing molten condensate to flow away through the opening. Preferably, the refrigerant line includes a metal pipe at the point to be heated; more preferably, the refrigerant line consists entirely of a metal pipe. This ensures that the heat can be efficiently transferred to the environment.

[0024] For example, the refrigerant line is arranged in a defrosting zone, which includes the opening of the defrost water drain. A defrosting zone, as understood by those skilled in the art, is an area around the appropriately heated line where the heat is sufficient to melt any ice that has formed. Because the opening of the defrost water drain is also included, it remains ice-free, and the melted water can drain away accordingly. Preferably, the defrosting zone is arranged radially up to 20 cm away from the refrigerant line.

[0025] The problem according to the invention is further solved by a method for operating the de-icing system comprising the following steps: a) Determining that a predetermined outside temperature has been undershot and / or that a predetermined period has elapsed and / or that icing has occurred b) Activation of the de-icing system c) Melting of formed ice d) Runoff of meltwater via a defrost water drain.

[0026] For example, the detection of icing can depend on the amount of defrosting, which is preferably determined by a sensor. Targeted or periodic activation of the defrosting system ensures that excessive ice buildup does not occur and that the defrosting water drain remains continuously defrosted.

[0027] Furthermore, the problem according to the invention is solved by a vehicle comprising the aforementioned de-icing system.

[0028] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. The drawings show: Fig. 1 Defrosting system with an electric heating element in a side view, Fig. 2 Defrosting system with an electric heating element in a bottom view, Fig. 3 Defrosting system with one refrigerant line in a side view, Fig. 4 Defrosting system with a refrigerant line in a bottom view, and Fig. 5 a to d schematic representation of opening shapes of a defrost water drain with electric heating element in a bottom view, Fig. 6. Schematic representation of the process steps of a procedure for operating the de-icing system, and Fig. 7. Schematic representation of a vehicle having a de-icing system.

[0029] In the figures, the same constructive elements each have the same reference symbols.

[0030] Fig. Figure 1 shows a de-icing system 100 in a vehicle 29 (not shown) with a heat pump (not shown) in a side view in the direction of travel A, wherein the de-icing system 100 comprises a de-icing device 10 and a defrost water drain 11. The defrost water drain 11 is arranged here in a first cooling air path 12 in the direction of an underbody 13. Alternatively, the defrost water drain can also be arranged in a second cooling air path 14 or in both, which is not shown here. The first cooling air path 12 is arranged here between a first radiator 15 and a fan 16, wherein the first radiator 15 is here a gas radiator 17, and a second radiator 18 is formed parallel to the gas radiator 17, wherein this second radiator 18 is here a low-temperature radiator 19. Water condenses on the gas radiator 17, with the water freezing to ice 20 at low temperatures.The ice 20 is thawed by the de-icing device 10, which here is designed as an electric heating element 21. The resulting defrost water 22 can then drain through an opening 23 of the defrost water drain towards the underbody 13 and onto a road 24. The opening 23 is designed here as a slot 23a, with the first end 25 of the slot 23a, which faces the direction of travel, having an angle of at least 20° towards the road 24. This allows the defrost water 22 to drain more efficiently. The electric heating element 21 is connected to a charging device 26 of the vehicle, so that defrosting can occur at least during each charging process of the vehicle's battery. Furthermore, the dense packing of the electric heating element 21 in the first cooling air path 12 ensures that the ice 20 formed on the gas cooler 17 is efficiently defrosted and thus no icing of the defrost water drain 11 and / or the opening 23 occurs.

[0031] The Fig. Figure 2 shows the de-icing system 100 according to Fig. Figure 1 shows a view from below. This illustrates the positive-locking connection of the electric heating element 21 between the fan 16 and the gas cooler 17. The second cooling air path 14 between the gas cooler 17 and the low-temperature cooler 19 does not have a defrost water drain 11; this is located in the first cooling air path 12. The opening 23 is designed as a long slot 23a, so that defrost water 22 is efficiently drained across the entire width B of the first cooling air path 12.

[0032] In Fig. Figure 3 shows an alternative or additional embodiment of the defrosting device 10. Here, the defrosting device 10 is designed as a refrigerant line 27 heated to 10 °C in the form of an extruded profile. The refrigerant line 27 is arranged in a defrosting zone 28, which is located on the side of the first cooling air path 12 facing the underbody 13 and includes the defrost water drain 11 and the opening 23. Within the defrosting zone 28, the formation of ice 20 is therefore prevented, or the ice 20 is melted. In particular, the proximity to the opening 23 prevents it from freezing over, and the defrost water 22 can drain freely through the opening 23.

[0033] Fig. Figure 4 shows the de-icing system 100 according to Fig. Figure 3 shows a view from below. The defrosting device 10 is designed here as a refrigerant line 27 and covers the slot 23a of the defrost water drain 11 in such a way that any ice that forms is efficiently melted or cannot form at all. A refrigerant line 27 can also be formed in the second cooling air path 14, in which case a defrost water drain 11 would also be provided. However, this is not shown here.

[0034] Fig. Figure 5a shows the defrosting system 100 with the electric heating element 21, wherein the defrost water drain has a slot 23a, the length of the slot 23a being over 66% of a width B of the first cooling air path 12.

[0035] Fig. 5b shows the de-icing system 100 from Fig. 5b, wherein Fig. 5b shows two slots 23a.

[0036] Fig. 5c shows the de-icing system 100 from Fig. 5a, wherein in Fig. 5c instead of one slot 23a two holes 23b are arranged in the defrost water drain 11.

[0037] Fig. 5d shows the de-icing system 100 from Fig. 5c, wherein in Fig. 5d instead of two holes 23b has four holes 23b which are arranged in the defrost water drain 11.

[0038] Fig. Figure 6 shows the schematic procedure for operating the de-icing system 100. First, in step a), it is determined whether de-icing is necessary, or preventive de-icing is planned. If the outside temperature is below 0 °C, preventive de-icing is recommended, as there is a chance that condensate from the gas cooler 17 has frozen. Then, in step b), the de-icing system 100 is activated. This then melts the ice 20 in step c) by the electric heating element 21 and keeps the refrigerant line 27, heated to at least 10 °C, clear of the openings 23 of the defrost water drain 11. In step d), the defrost water 22 then flows away unimpeded. This, in particular, inhibits re-icing after the de-icing system is switched off.

[0039] Fig. Figure 7 shows an electric vehicle 29 which has a de-icing system 100. Reference symbol list 10 De-icing device 11 Defrost water drain 12 first cooling air path 13 Underbody 14 second cooling air path 15 first coolers 16 fans 17 gas coolers 18 second cooler 19 Low-temperature coolers 20 ice cream 21 electric heating element 22 Defrost water 23 Opening 23a Slot 23b Hole 24th Street 25 first end 26 Charging device 27 Refrigerant line 28 De-icing zone 29 electric vehicles A direction of travel B Width a to d process steps 100 De-icing system QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 112 293 A1

[0002] DE 10 2020 200 079 A1

[0003] DE 10 2018 131 026 A1

[0004] DE 10 2021 211 228 A1

[0005]

Claims

[1] Defrosting system (100) in an electric vehicle (29) for a heat pump, wherein the defrosting system (100) comprises at least one defrosting device (10) and at least one defrost water drain (11). [2] De-icing system (100) according to claim 1, characterized by , that the at least one defrost water drain (11) is arranged in a first cooling air path (12) and / or in a second cooling air path (14) of the vehicle. [3] De-icing system (100) according to claim 2, characterized by , that the first cooling air path (12) is formed between a first cooler (15) and a fan (16), wherein preferably the first cooler (15) is a gas cooler (17). [4] De-icing system (100) according to claim 2 or 3, characterized by , that the second cooling air path (14) is formed between the first cooler (15) and a second cooler (18), wherein preferably the second cooler (18) is a low-temperature cooler (19). [5] De-icing system (100) according to any one of the preceding claims, characterized by , that the defrost water drain (11) comprises at least one opening (23), wherein the opening (23) is designed in the direction of an underbody (13) of the vehicle, wherein the opening (23) in particular has a rectangular, oval and / or round shape, preferably the defrost water drain (11) comprises at least two openings (23), more preferably at least three openings (23). [6] De-icing system (100) according to any one of the preceding claims, characterized by , that the defrosting device (10) is designed as an electric heating element (21), wherein the electric heating element (21) is arranged between the first cooler (15) and the fan (16). [7] De-icing system (100) according to claim 6, characterized by , that the electric heating element (21) is part of a charging device (25) for charging an electric vehicle battery. [8] De-icing system (100) according to any one of claims 1 to 5, characterized by , that the defrosting device (10) is designed as a refrigerant line (27) preferably heated to at least 10 °C, wherein the refrigerant line (27) is preferably designed as a round tube and / or as an extruded profile. [9] De-icing system (100) according to claims 5 and 8, characterized by , that the refrigerant line (27) is arranged in a defrosting zone (28), wherein the defrosting zone (28) includes the opening (23) of the defrosting water drain (11). [10] Method for operating the de-icing system (100) according to any one of the preceding claims comprising the following steps: a) Determining that a predetermined outside temperature has been undershot and / or that a predetermined period has elapsed and / or that icing has occurred b) Activation of the de-icing system (10) c) Melting of formed ice (20) d) Runoff of defrost water (22) via a defrost water drain (11)

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