Motor vehicle comprising a coolant circuit and the control unit assigned to the coolant circuit for suppressing boiling noises

Abstract

The invention relates to a motor vehicle (200) comprising an internal combustion engine drive and / or an electric drive (202), wherein the motor vehicle (200) has: a primary coolant circuit (10); a secondary fluid circuit (12); a heat exchanger (14) which is designed to provide a thermal operative connection between the primary coolant circuit (10) and the secondary fluid circuit (12); a first control unit (18) associated with the primary coolant circuit (10); a temperature sensor (20) associated with the primary coolant circuit (10); and a heating device (22) associated with the primary coolant circuit (10). According to the invention, the heating device (22) is an electric resistance heater (22w) having a heating element (22h) around which the coolant flows and which is designed to heat the coolant, and the control unit (18) is designed to adjust the electric resistance heater (22w) to a first heating power value (HW1) based on a coolant temperature signal (t) from the temperature sensor (20), wherein the first heating power value (HW1) is selected in such a way that heat at the heating element (22h) is transferred in the range of convection boiling.

Description

[0001] Motor vehicle with coolant circuit and control unit assigned to the coolant circuit for suppressing boiling noises

[0002] DESCRIPTION:

[0003] The invention relates to a motor vehicle with an internal combustion engine and / or electric drive, wherein the motor vehicle comprises: a primary coolant circuit; a secondary fluid circuit; a heat exchanger configured to provide a thermal operative connection between the primary coolant circuit and the secondary fluid circuit; a first control unit associated with the primary coolant circuit; a temperature sensor associated with the primary coolant circuit; and a heating device associated with the primary coolant circuit.

[0004] Such a motor vehicle is known, for example, from DE 101 25 589 A1, in which an auxiliary heater with a burner is used to heat a cooling fluid. Furthermore, with regard to the control of heaters in motor vehicles, reference is made to DE 195 11 545 A1 and US 2011 042 988 A1.

[0005] Heated coolant or coolant fluid in the primary circuit is used to transfer the supplied heat to a medium (fluid) in the secondary circuit. The medium (e.g., air or cooling water) in the secondary circuit is thereby heated, particularly with the use of a heat exchanger, to ultimately increase the temperature of an interior or other component of the vehicle.

[0006] It has been shown that when coolant is heated or heated, acoustically and / or haptically perceptible vibrations can occur, which are perceived as unpleasant or disturbing by people in the interior of the motor vehicle.

[0007] The object underlying the invention is to provide a motor vehicle in which an optimized operation of the heating device assigned to the primary coolant circuit can be optimized with regard to acoustically and / or haptically perceptible vibrations.

[0008] This problem is solved by a motor vehicle having the features of the independent patent claim. Advantageous embodiments with useful further developments are specified in the dependent patent claims.

[0009] A motor vehicle with an internal combustion engine and / or electric drive is therefore proposed, the motor vehicle comprising: a primary coolant circuit; a secondary fluid circuit; a heat exchanger configured to provide a thermal operative connection between the primary coolant circuit and the secondary fluid circuit; a first control unit associated with the primary coolant circuit; a temperature sensor associated with the primary coolant circuit; and a heating device associated with the primary coolant circuit.It is provided that the heating device is an electrical resistance heater with a heating element around which the coolant flows, which heating element is designed to heat the coolant, and that the control unit is designed to adjust the electrical resistance heater to a first heating power value as a function of a coolant temperature signal from the temperature sensor, wherein the first heating power value is selected such that heat transfer to the heating element takes place in the region of convection boiling.

[0010] In an electric resistance heater, gas bubbles forming on the surface of the heating element rise due to their lower density compared to the coolant or cooling liquid. As the distance from the heating element increases, the coolant temperature surrounding the gas bubbles decreases. This leads to a collapse of the gas bubbles, which subsequently generates sound waves or vibrations that are perceptible acoustically and / or tactilely.

[0011] The proposed control unit allows the resistance heater to be operated in such a way that no or hardly any gas bubbles form at the heating element due to the setting to a first heating power value at which heat transfer to the heating element occurs in the convection boiling range. This prevents the occurrence of unwanted vibrations, albeit at the expense of slightly reduced heating power, enabling quiet operation of the heating device.

[0012] In the motor vehicle, the control unit can be configured to receive at least one background noise parameter and, depending on the at least one background noise parameter, to adjust the electrical resistance heater to a second heating power value, wherein the second heating power value is selected such that heat transfer to the heating element occurs in the nucleate boiling region.

[0013] This makes it possible to achieve increased heating performance, which is particularly adjusted or used when one or more background noises are present, which are represented by corresponding background noise parameters.

[0014] In the motor vehicle, the background noise parameter may be at least one of the following:

[0015] Speed ​​of an interior fan of an air conditioning unit;

[0016] Speed ​​of a refrigerant compressor in a refrigeration system;

[0017] Speed ​​of a running internal combustion engine;

[0018] Speed ​​of the motor vehicle;

[0019] Set volume of a multimedia system;

[0020] Measured noise level in an interior of the motor vehicle, in particular in a front area of ​​the interior;

[0021] Recorded or calculated rolling noise of a moving vehicle. The engine's speed can also be used to determine whether the engine is idling.

[0022] In the motor vehicle, the control unit can be configured to variably adjust the heating power value between the first heating power value and the second heating power value, so that a boiling noise generated in the primary coolant circuit in the region of the resistance heater is not acoustically and / or haptically perceptible to a person in the motor vehicle compared to at least one background noise represented by the at least one background noise parameter.

[0023] In other words, the heating output value for the resistance heater can be flexibly adjusted. For example, it is conceivable that when the vehicle is stationary, such as at an intersection, the heating output value could be set closer to the first heating output value, particularly because there is no rolling noise as a background noise parameter. As soon as the vehicle starts moving again, the rolling noise increases again, and the heating output value can be set closer to the second heating output value, accepting more boiling noise, which, however, is imperceptible due to the background noise.

[0024] The motor vehicle may have a purely electric drive, wherein the background noise parameter is at least one of the following variables: speed of an interior fan of an air conditioning unit;

[0025] Speed ​​of a refrigerant compressor in a refrigeration system;

[0026] Speed ​​of the motor vehicle;

[0027] Set volume of a multimedia system;

[0028] Measured noise level in an interior of the motor vehicle, in particular in a front area of ​​the interior;

[0029] Recorded or calculated rolling noise of the moving vehicle.

[0030] In a purely electrically powered vehicle, the background noise of the running combustion engine is eliminated, so that there is generally less background noise in the interior of such an electric vehicle.

[0031] Accordingly, other background noise parameters may be more important, such as the speed of an interior fan, the noise of which is perceived as louder in an electric vehicle than in a vehicle with a combustion engine.

[0032] In the motor vehicle, the control unit can be configured to calculate a resulting background noise value taking all background noise parameters into account when several different background noise parameters are present, and to adjust the heating power of the resistance heater depending on the resulting background noise value.

[0033] Furthermore, it is possible that, based on recorded operating variables such as the speed of the motor vehicle, an ambient noise parameter such as rolling noise is determined, for example by calculation or a stored characteristic map.

[0034] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures.

[0035] Fig. 1 shows a schematic and simplified view of a motor vehicle with a coolant circuit.

[0036] In Fig. 1, a motor vehicle 200 is shown in a simplified and schematic manner as a dashed rectangle.

[0037] Motor vehicle 200 has an internal combustion engine and / or electric drive 202, which is also illustrated only in simplified form as a rectangle. Motor vehicle 200 further has a primary coolant circuit 10 and a secondary fluid circuit 12.

[0038] A heat exchanger 14 is configured to provide a thermal connection between the primary coolant circuit 10 and the secondary fluid circuit 12.

[0039] It should be noted that the second fluid circuit 12 is only shown in a simplified manner. The fluid present therein can be, for example, air or a liquid, wherein the fluid is heated with the intention of heating the interior air of the motor vehicle 200.

[0040] The primary coolant circuit 10 further includes a coolant pump 16. A first control unit 18 is associated with the primary coolant circuit 10. Furthermore, the primary coolant circuit 10 includes a temperature sensor 20. The temperature sensor 20 is configured, in particular, to detect the coolant temperature.

[0041] The primary coolant circuit 10 is also assigned a heating device 22 which is designed to heat the coolant as required.

[0042] The control unit 18 is configured to control or regulate the heating device 22 (heating signal h). Furthermore, the control unit 18 can also control or regulate the coolant pump 16 (pump control signal p). The temperature sensor 20 can transmit a temperature signal t to the control unit 18, which can be further processed by the latter.

[0043] The heating device 22 is an electrical resistance heater 22w with a heating element 22h around which the coolant flows, which is illustrated here in a simplified manner by three wavy lines.

[0044] In a resistance heater, for example, a heating plate (heating element) in contact with the coolant, in particular a metallic one, can be heated by means of an electric heating coil, so that the coolant can be heated at the heating plate.

[0045] The control unit 18 is configured to adjust the electrical resistance heater 22w to a first heating power value HW1 as a function of a coolant temperature signal t of the temperature sensor 20, wherein the first heating power value HW1 is selected such that heat transfer to the heating element 22h occurs in the range of convection boiling.

[0046] The control unit 18 is further configured to receive at least one background noise parameter NG and, depending on the at least one background noise parameter NG1, NG2, NG3, NGn, to adjust the electrical resistance heater 22w to a second heating power value HW2, wherein the second heating power value HW2 is selected such that heat transfer to the heating element 22h occurs in the nucleate boiling region.

[0047] The background noise parameter NG1, NG2, NG3, NGn can be one of the following values:

[0048] Speed ​​of an interior fan of an air conditioning unit 204;

[0049] Speed ​​of a refrigerant compressor of a refrigeration system 206;

[0050] Speed ​​of a running internal combustion engine 202;

[0051] Speed ​​of the motor vehicle 200;

[0052] Set volume of a multimedia system 208;

[0053] Measured volume in an interior of the motor vehicle 200, in particular in a front area of ​​the interior;

[0054] Recorded or calculated rolling noise of the moving motor vehicle 200.

[0055] The control unit 18 is in particular configured to variably adjust the heating power value between the first heating power value HW1 and the second heating power value HW2, so that a boiling noise generated in the primary coolant circuit 10 in the region of the resistance heater 22w is not acoustically and / or haptically perceptible to a person in the motor vehicle 200 in comparison to at least one background noise represented by the at least one background noise parameter NG1, NG2, NG3, NGn.

[0056] The drive 202 of the motor vehicle 200 can be purely electric, wherein the secondary noise parameter NG1, NG2, NG3, NGn is at least one of the following variables:

[0057] Speed ​​of an interior fan of an air conditioning unit 204;

[0058] Speed ​​of a refrigerant compressor of a refrigeration system 206; speed of the motor vehicle;

[0059] Set volume of a multimedia system 208;

[0060] Measured volume in an interior of the motor vehicle 200, in particular in a front area of ​​the interior;

[0061] Recorded or calculated rolling noise of the moving motor vehicle 200.

[0062] In the motor vehicle 200, the control unit 18 is configured to calculate a resulting background noise value NGres taking all background noise parameters into account when several different background noise parameters NG1, NG2, NG3, NGn are present, and to adjust the heating power HW of the resistance heater 22h as a function of the resulting background noise value NGres.

[0063] With the help of the functionality of the control unit 18 described above, the heating device 22 or the resistance heater 22w can be operated in a range of high heat flux densities without having to accept acoustic restrictions in the vehicle interior. The (bubble) boiling of the coolant or the cooling liquid in the electrical resistance heater 22w is permitted, on the one hand, depending on the temperature of the cooling liquid, to a degree such that no boiling noises can be perceived. On the other hand, the heating output of the electrical resistance heater 22w is increased depending on the background noise (background noise parameters NG1, NG2, NG3, NGn), so that the cooling liquid begins to boil in order to reach a target temperature of the interior or other components as quickly as possible, but without the boiling noises being audible to the vehicle occupants because the background noises are louder or louder.are louder than the boiling noise of the 22w resistance heater.

Claims

PATENT CLAIMS: 1 . A motor vehicle (200) with an internal combustion engine and / or electric drive (202), the motor vehicle (200) comprising: a primary coolant circuit (10); a secondary fluid circuit (12); a heat exchanger (14) configured to provide a thermal operative connection between the primary coolant circuit (10) and the secondary fluid circuit (12); a first control unit (18) associated with the primary coolant circuit (10); a temperature sensor (20) associated with the primary coolant circuit (10);a heating device (22) assigned to the primary coolant circuit (10), characterized in that the heating device (22) is an electrical resistance heater (22w) with a heating element (22h) around which the coolant flows, which heating element is designed to heat the coolant, and in that the control unit (18) is designed to adjust the electrical resistance heater (22w) to a first heating power value (HW1) as a function of a coolant temperature signal (t) of the temperature sensor (20), wherein the first heating power value (HW1) is selected such that heat transfer to the heating element (22h) takes place in the range of convection boiling; 2. Motor vehicle (200) according to claim 1, characterized in that the control unit (18) is designed to receive at least one background noise parameter (NG1, NG2, NG3, NGn) and, depending on the at least one background noise parameter (NG1, NG2, NG3, NGn), to adjust the electrical resistance heater (22w) to a second heating power value (HW2), wherein the second heating power value (HW2) is selected such that heat transfer to the heating element (22h) takes place in the nucleate boiling region.

3. Motor vehicle (200) according to claim 2, characterized in that the background noise parameter (NG1, NG2, NG3, NGn) is at least one of the following variables: Speed ​​of an interior fan of an air conditioning unit (204); speed of a refrigerant compressor of a refrigeration system (206); speed of a running internal combustion engine (202); Speed ​​of the motor vehicle (200); Set volume of a multimedia system (208); Measured volume in an interior of the motor vehicle (200), in particular in a front area of ​​the interior; Recorded or calculated rolling noise of the moving motor vehicle (200).

4. Motor vehicle (200) according to claim 2 or 3, characterized in that the control unit (18) is designed to variably set the heating power value between the first heating power value (HW1) and the second heating power value (HW2), so that a boiling noise arising in the primary coolant circuit (10) in the region of the resistance heater (22w) is not acoustically and / or haptically perceptible to a person in the motor vehicle (200) in comparison to at least one background noise represented by the at least one background noise parameter (NG1, NG2, NG3, NGn).

5. Motor vehicle (200) according to one of claims 2 to 4, characterized in that it has a purely electric drive (202), wherein the background noise parameter (NG1, NG2, NG3, NG4) is at least one of the following variables: Speed ​​of an interior fan of an air conditioning unit (204); speed of a refrigerant compressor of a refrigeration system (206); speed of the motor vehicle (200); Set volume of a multimedia system (208); Measured volume in an interior of the motor vehicle (200), in particular in a front area of ​​the interior; Recorded or calculated rolling noise of the moving motor vehicle (200).

6. Motor vehicle (200) according to one of claims 2 to 5, characterized in that the control unit (18) is configured to calculate a resulting background noise value (NGres) taking all background noise parameters into account when several different background noise parameters (NG1, NG2, NG3, NGn) are present, and to adjust the heating power (HW) of the resistance heater (22w) as a function of the resulting background noise value (NGres).

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