阅读说明：本技术 超声波传感器装置、制冷回路和车辆 (Ultrasonic sensor device, refrigeration circuit and vehicle ) 是由 费里特·奥泽尼尔 伯恩德·迪恩哈特 比约恩·内斯特勒 马可·施尼克斯 维克多·伯格曼 于 2020-09-16 设计创作，主要内容包括：具体说明了一种用于分析液体的超声波传感器装置1,该超声波传感器装置1具有布置在发射器保持元件2上的超声波发射器3和布置在接收器保持元件4上的超声波接收器5,其中超声波发射器3和超声波接收器5相对于彼此以不变的距离6布置。发射器保持元件2和/或接收器保持元件4被成形为蜿蜒或螺旋形。此外,具体说明了一种制冷回路12和一种车辆21。(In particular, an ultrasonic sensor device 1 for analyzing liquids is specified, the ultrasonic sensor device 1 having an ultrasonic transmitter 3 arranged on a transmitter holding element 2 and an ultrasonic receiver 5 arranged on a receiver holding element 4, wherein the ultrasonic transmitter 3 and the ultrasonic receiver 5 are arranged at a constant distance 6 from one another. The transmitter holding element 2 and/or the receiver holding element 4 are shaped as a meander or spiral. Furthermore, a refrigeration circuit 12 and a vehicle 21 are specified.)

1. An ultrasonic sensor device (1) for analyzing a liquid, having an ultrasonic transmitter (3) arranged on a transmitter holding element (2) and an ultrasonic receiver (5) arranged on a receiver holding element (4), wherein the ultrasonic transmitter (3) and the ultrasonic receiver (5) are arranged at a constant distance (6) from each other, characterized in that the transmitter holding element (2) and/or the receiver holding element (4) are shaped as a meander or spiral.

2. The ultrasonic sensor device (1) according to any one of the preceding claims, characterized in that the ultrasonic sensor device (1) has a stabilizing element (7) designed for fixing the holding elements (2, 4).

3. An ultrasonic sensor device (1) according to any of the preceding claims, characterized in that the holding elements (2, 4) and/or the stabilizing element (7) are arranged in one plane.

4. According to any one of the preceding claimsThe ultrasonic sensor device (1) according to item (b), characterized in that the pressure drop over the ultrasonic sensor device (1) is not more than 15 · 10⁴Pa, preferably not more than 5-10⁴Pa。

5. The ultrasonic sensor device (1) according to any one of the preceding claims, characterized in that the ultrasonic sensor device (1) has a pressure sensor (8).

6. The ultrasonic sensor device (1) according to claim 5, characterized in that the pressure sensor (8) is arranged perpendicular to the main flow direction (9) of the liquid (10) to be analyzed.

7. The ultrasonic sensor device (1) according to any one of the preceding claims, characterized in that a temperature sensor (11) is arranged in the region of the ultrasonic transmitter (3) and/or ultrasonic receiver (5).

8. The ultrasonic sensor device (1) according to any of the preceding claims, characterized in that the ultrasonic transmitter (3) is designed to transmit sound waves with a phase shift and/or frequency modulation in order to cancel sound waves with a wavelength in the audible range.

9. Refrigeration circuit (12) with a compressor (13), a condenser (14), an expansion valve (15) and an evaporator (16), characterized in that the refrigeration circuit (12) has an ultrasonic sensor device (1) according to any of the preceding claims.

10. Refrigeration circuit (12) according to claim 9, characterized in that the ultrasonic sensor device (1) is arranged downstream of the condenser (14) and upstream of the expansion valve (15).

11. Refrigeration circuit (12) according to claim 9 or 10, characterized in that the refrigeration circuit (12) has an internal heat exchanger (17), the internal heat exchanger (17) having a chamber (18) for liquid refrigerant and a chamber (19) for gaseous refrigerant, wherein the ultrasonic sensor device (1) is arranged upstream or downstream of the chamber (18) for liquid refrigerant.

12. Refrigeration circuit (12) according to claim 9, characterized in that a collection and drying unit (20) is associated with the condenser (14), wherein the ultrasonic sensor device (1) is arranged in a lower region of the collection and drying unit (20).

13. Vehicle (21) having a refrigeration circuit (12) according to any one of claims 9 to 12.

Technical Field

The invention relates to an ultrasonic sensor device for analyzing liquids, having an ultrasonic transmitter arranged on a transmitter holding element and an ultrasonic receiver arranged on a receiver holding element, wherein the ultrasonic transmitter and the ultrasonic receiver are arranged at a constant distance from one another. Furthermore, the invention relates to a refrigeration circuit having a compressor, a condenser, an expansion valve and an evaporator, and also to a vehicle.

Background

Ultrasonic sensors can be used for analyzing liquids, for example refrigerant in a refrigeration circuit (EP 3376139 a 1). The ultrasonic sensor has an ultrasonic transmitter and a corresponding ultrasonic receiver which are arranged at a specific constant distance from one another.

The ultrasonic transmitter transmits ultrasonic waves, which are received by the ultrasonic receiver. The ultrasonic transmitter and the ultrasonic receiver respectively transmit the transmitted or received signals to a processing unit, which calculates the speed of sound from these signals.

The measured values for the pressure and temperature of the liquid to be analyzed are also incorporated into the calculation of the speed of sound. The calculated speed of sound can be compared to the tabulated values from which inferences can be drawn regarding the composition of the liquid. For example, it may be determined how much oil is in the refrigerant (oil in the cycle, OIC) or whether the refrigerant is contaminated with other substances. Evaluation of the measurement results is described, for example, in MEYER, j.j.; JABARDO, j.m.s, an ultrasonic device for measuring the concentration of oil in flowing liquid refrigerant, ACRC TR-24, 1992-9, pages 1-10.

The ultrasonic transmitter and the ultrasonic receiver are usually each arranged at the end of a rod, wherein the rods are connected to each other in the form of a fork. Both the ultrasonic transmitter and the ultrasonic receiver are immersed in the liquid to be investigated. After the ultrasonic transmitter has emitted ultrasonic waves, the latter move on the one hand through the liquid and on the other hand through the rods connected to one another. Since the distance between the ultrasonic transmitter and the ultrasonic receiver through the liquid is smaller than the distance through the rod, the ultrasonic waves reach the ultrasonic receiver faster through the liquid than through the rod.

This known sensor design has the disadvantage that the sensor occupies a large amount of installation space. The available sensors have a length of, for example, about 65mm and a diameter of about 20 mm. Together with the required housing for housing the sensor and taking into account the high pressures prevailing in the refrigeration circuit, a total mounting length of about 150mm is obtained, as well as a diameter of about 40 mm. The result of these large dimensions, the weight associated therewith and the costs is that the refrigeration circuit of the vehicle is equipped only with such sensors for testing purposes. In contrast, continuous analysis of the refrigerant and monitoring of the refrigeration circuit is not feasible or is only possible to a very limited extent.

Disclosure of Invention

The present invention is based on the object of providing an option which at least reduces the above-mentioned disadvantages.

This object is achieved by the subject matter of the independent claims. Advantageous developments of the invention are specified in the dependent claims.

A first aspect of the invention relates to an ultrasonic sensor device for analyzing a liquid, having an ultrasonic transmitter arranged on a transmitter holding element and an ultrasonic receiver arranged on a receiver holding element, wherein the ultrasonic transmitter and the ultrasonic receiver are arranged at a constant distance from one another.

The ultrasonic transmitter and the ultrasonic receiver are preferably arranged at one end of the transmitter holding element or the receiver holding element, respectively. The holding element serves to position the ultrasound transmitter or the ultrasound receiver in the ultrasound sensor device. At the same time, they can be used for signaling connections of ultrasonic transmitters or receivers. The holding element can have a connection unit at the end opposite the ultrasound transmitter or receiver, with which the fastening to the housing and/or the connection of the processing unit to the ultrasound transmitter or receiver can be effected.

The ultrasonic sensor device may have a housing in which the units of the device are arranged, i.e. for example an ultrasonic transmitter and an ultrasonic receiver comprising a holding element. The liquid to be analyzed can flow into and out of the ultrasonic sensor device through openings in the housing, wherein the main flow direction of the liquid depends on the particular installation situation. In general, the ultrasonic transmitter and the ultrasonic receiver are arranged in such a way that the distance between the ultrasonic transmitter and the ultrasonic receiver through the liquid is smaller than the distance through the holding element.

According to the invention, it is provided that the transmitter holding element, the receiver holding element or both the transmitter holding element and the receiver holding element are formed in a meandering or spiral shape.

The holding element can be shaped, for example, in the form of an elongated wire made of, for example, rust-preventive steel.

Serpentine shaped means that the holding element has a plurality of bends, resulting in a loop, a folded structure, etc. By helically shaped is meant that the holding element has turns, preferably at least two turns.

Both the meandering as well as the helical shaping have the effect that the linear distance between the end of the holding element at which the ultrasonic transmitter or receiver is arranged and the other end of the holding element, which can be used for connection to the processing unit, is significantly shorter than the length of the holding element along the meandering or helical structure. The path covered by the ultrasound waves through the holding element is therefore significantly longer than the path of a conventional linear shaping of the holding element, and accordingly more time is required for the path to be covered by the holding element.

The shaping of the holding element or holding elements according to the invention advantageously enables a miniaturization of the ultrasonic sensor device, since due to the meandering or spiral-shaped shaping the linear distance can be reduced without shortening the duration of the covered course by the holding element. Material requirements and construction costs can be reduced compared to conventional ultrasonic sensor devices.

The ultrasonic sensor device may be used for analyzing a liquid, for example, a refrigerant of a refrigeration circuit of a climate control system of a vehicle. For example, the oil content (OIC) or other material content of the refrigerant may be determined. A deviation of the oil content from the predetermined value may be indicative of a failure of the refrigeration circuit. For example, a fault may be presumed where the standard deviation of the oil content is greater than 10% of the mean value under substantially consistent external conditions, such as over a period of milliseconds to minutes. Furthermore, there is an option to determine the sub-cooled state of the refrigerant. If undercooling is not present, bubbles will form, resulting in a varying speed of sound and can be detected accordingly. Subcooling is the temperature difference between the refrigerant temperature and the vaporization temperature at the current pressure.

For example, if it is established that the standard deviation of the OIC content is greater than 10%, and that the subcooling of the refrigerant is not established at a constant speed of the vehicle at ambient temperatures above 20 ℃, this may be indicative of a lack of refrigerant.

In contrast, a standard deviation of greater than 10% with sufficient subcooling under steady state operating conditions may indicate contamination of the refrigerant. If the oil content changes slowly over a period of time, this may indicate that there is water in the refrigeration circuit. If the oil content changes suddenly, this may indicate a compressor problem or other contamination.

Due to the miniaturized option, the ultrasonic sensor device can be used not only for testing purposes, such as test bench studies, but also for on-line analysis, i.e. progressive or periodic monitoring of the refrigeration circuit. For example, the ultrasonic sensor device may be installed to remain in each vehicle. The available measurements (e.g., oil content of the refrigerant) may be used to adjust the refrigeration circuit (e.g., compressor, expansion valve, etc.), such that higher performance may be achieved and operational reliability may be increased and damage may be reduced.

According to various embodiment variants, the ultrasonic sensor device can have a stabilizing element, which is designed to fix the holding element.

For example, by stabilizing the element, vibration of the holding element can be reduced or prevented, so that the influence of the measurement value can be cancelled out and a more reliable measurement result can be obtained. The stabilizing element can preferably be designed and arranged in such a way that the flow rate and the flow of the liquid to be analyzed through the ultrasonic sensor device are influenced as little as possible. Turbulence is to be substantially avoided.

For example, an additional stabilizing element may be used to connect an annular stabilizing element radially to the housing of the ultrasonic sensor device, which is arranged centrally in the ultrasonic sensor device perpendicular to the main flow direction of the liquid to be analyzed.

The material of the stabilizing element is chosen such that the transmitted ultrasonic waves do not travel faster through the stabilizing element to the ultrasonic receiver than through the path of the liquid. Possible materials may be plastics, such as polyethylene or composites. Furthermore, the connection point between the stabilizing element and the retaining element can be separated.

According to further embodiment variants, the holding element and/or the stabilizing element can be arranged in one plane. The plane is preferably oriented perpendicular to the main flow direction of the liquid to be analyzed. This plane is defined by the main extension direction of the holding or stabilizing element.

Thus, it is advantageous to influence the flow velocity and flow of the liquid to be analyzed as little as possible, thereby obtaining more reliable measurement results. Furthermore, the ultrasonic transmitter and/or the ultrasonic receiver may also be arranged in the same plane as the holding element or the stabilizing element.

The ultrasonic sensor device may preferably be designed in such a way that the pressure drop over the ultrasonic sensor device is as small as possible, so that the supercooling effect on the refrigerant is as small as possible. The specific allowable pressure drop depends inter alia on the refrigerant, since the material properties of the various refrigerants are very different.

The pressure drop on the ultrasonic measuring device can reach 15.10 by using the refrigerant R744⁴Pa. For hydrocarbon based refrigerants, such as R134a, R1234yf, R290, etc., the pressure drop cannot be greater than 5 · 10⁴Pa。

The pressure drop may be influenced, for example, by the cross-section, number and arrangement of the holding elements and possibly of the stabilizing elements. The specific pressure drop may be determined, for example, by flow simulation.

According to a further embodiment variant, the ultrasonic sensor device can have a pressure sensor.

The pressure of the liquid to be analyzed can be determined directly by the pressure sensor inside the ultrasonic sensor device. Since pressure is required as a parameter for calculating the sound speed, the sound speed can be calculated particularly accurately by pressure determination within the ultrasonic sensor device.

The pressure sensor may preferably be arranged perpendicular to the main flow direction of the liquid to be analyzed, furthermore preferably upstream of the ultrasonic transmitter and the ultrasonic receiver. An arrangement perpendicular to the main flow direction is preferred, since then no dynamic pressure has to be taken into account. An upstream arrangement is preferred, since in this case the pressure drop over the ultrasonic sensor device does not have to be taken into account. The influence of flow phenomena on the pressure measurement, for example caused by the ultrasonic transmitter and the ultrasonic receiver and the corresponding holding element, can thus be reduced.

According to further embodiment variants, the temperature sensor can be arranged in the region of the ultrasonic transmitter and/or the ultrasonic receiver.

In addition to pressure, temperature also affects the speed of sound and is incorporated into its calculation. By arranging one or more temperature sensors in the region of the ultrasonic transmitter and/or the ultrasonic receiver, temperature measurements can be carried out in the region in which the speed of sound is to be determined, i.e. in the liquid between the ultrasonic transmitter and the ultrasonic receiver. The speed of sound can be calculated particularly accurately.

According to further embodiment variants, the ultrasonic transmitter may be designed to transmit sound waves with a phase shift and/or frequency modulation in order to cancel sound waves with a wavelength in the audible range. This cancellation may also be referred to as "active noise cancellation".

If sound waves in the audible range, for example having a frequency between 16Hz and 20Hz, which sound waves can be caused, for example, by a compressor of the refrigeration circuit, are detected, the ultrasonic transmitter can emit sound waves with a phase shift (for example, a phase shift of 180 °) and a suitable frequency modulation in order to eliminate the sound waves in the audible range.

Audible noise generation during operation of the ultrasonic sensor can be avoided. User acceptance can be increased.

The detection of sound waves in the audible range can be carried out, for example, by an ultrasonic receiver which, in addition to detecting ultrasonic waves, can also be designed to detect sound waves in the audible range. If a sound wave in the audible range is detected, a control signal may be generated and output that results in the sound wave being emitted with a phase shift to cancel the sound wave in the audible range.

Another aspect of the invention relates to a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator. According to the invention, it is provided that the refrigeration circuit furthermore has an ultrasonic sensor device according to the above description. The above-mentioned advantages of the ultrasonic sensor device are therefore linked correspondingly to the refrigeration circuit according to the invention.

The refrigeration circuit may furthermore optionally have an internal heat exchanger with a chamber for liquid refrigerant and a chamber for gaseous refrigerant.

The refrigeration circuit additionally has a line, for example in the form of a hose, a pipe or the like, with which the above-mentioned units of the refrigeration circuit are connected. In operation, refrigerant (e.g., R1234yf, R134a, or R744) flows through the refrigeration circuit. The properties of the refrigerant (e.g., oil content) can be easily and reliably determined by the ultrasonic sensor device. The analysis can be performed on-line, i.e. the ultrasonic sensor device is a permanent part of the refrigeration circuit, so that the analysis of the refrigerant can be performed progressively or periodically without the need to take refrigerant samples or to carry out a replacement of the refrigeration circuit.

According to various embodiment variants, the ultrasonic sensor device may be arranged downstream of the condenser and upstream of the expansion valve.

The refrigerant is advantageously liquid in this region, so that stable and reliable measurement results can be obtained.

According to a further embodiment variant, the refrigeration circuit may have an internal heat exchanger with a chamber for liquid refrigerant and a chamber for gaseous refrigerant, wherein the ultrasonic sensor device is arranged upstream or downstream of the chamber for liquid refrigerant of the internal heat exchanger. For example, the ultrasonic sensor device may be arranged downstream of the condenser and upstream of the chamber for liquid refrigerant, wherein the chamber for liquid refrigerant is correspondingly arranged upstream of the expansion valve.

An advantage of the arrangement downstream of the chamber for liquid refrigerant is that the refrigerant is more likely to be present in liquid form in this region, and thus a stable and reliable measurement result can be obtained. However, the upstream arrangement also functions under normal conditions.

According to a further embodiment variant, the collection and drying unit can be associated with a condenser, wherein the ultrasonic sensor device is arranged in a lower region of the collection and drying unit with respect to the installation situation in the refrigeration circuit. For example, the ultrasonic sensor device may be integrated in a filter of the collecting and drying unit.

This advantageously enables a space-saving housing of the ultrasonic sensor device if a collecting and drying unit is already provided. Furthermore, the drying cylinders of the collecting and drying unit are easy to replace, so that the refrigeration circuit can be simply retrofitted with the ultrasonic sensor device and the ultrasonic sensor device can be simply serviced.

Another aspect of the invention relates to a vehicle having a refrigeration circuit according to the above description. The advantages of the refrigeration circuit and the ultrasonic sensor device are therefore linked to such a vehicle accordingly.

A vehicle is to be understood here as any moving vehicle, i.e. a land vehicle and a water or air vehicle, for example a passenger car. The vehicle may be designed as an electric or hybrid electric vehicle, for example as a mild hybrid electric vehicle or a full hybrid electric vehicle.

The refrigeration circuit may be part of a climate control system of the vehicle. Due to the option of on-line analysis enabled by the ultrasonic sensor device according to the invention, improved regulation of the climate control system can be implemented, so that power consumption can be reduced over the entire life cycle. This can play a positive role, especially in electric vehicles, since batteries for climate control systems need to consume less energy and can therefore be extended in range.

Improved regulation may additionally lead to longer service life and more reliable operating conditions. The loss of refrigerant can be established early and the climate control system or the refrigeration circuit can be adjusted or shut down accordingly.

The miniaturization of the ultrasonic sensor devices achieved by the invention additionally has a particularly positive effect in the region of the vehicle, since the installation space in the vehicle is generally very limited, and conventional ultrasonic sensor devices are unsuitable for mass production for installing ultrasonic sensor devices which remain permanently in the vehicle on account of their large dimensions.

Drawings

In the following, the invention is explained in more detail on the basis of the figures and the associated description. In the drawings:

fig. 1 shows an ultrasonic sensor device according to the prior art;

FIG. 2 illustrates an exemplary ultrasound device;

FIG. 3 illustrates a cross-section of an exemplary ultrasound device;

FIG. 4 illustrates another exemplary ultrasound device;

FIG. 5 illustrates a cross-section of another exemplary ultrasound device;

FIG. 6 illustrates an exemplary refrigeration circuit;

FIG. 7 illustrates another exemplary refrigeration circuit;

FIG. 8 illustrates another exemplary refrigeration circuit;

FIG. 9 illustrates an exemplary collection and drying unit; and

FIG. 10 illustrates an exemplary vehicle.

Detailed Description

Fig. 1 shows an ultrasonic sensor device 1 according to the prior art. The ultrasonic sensor device 1 has an ultrasonic transmitter 3 arranged at one end of a transmitter holding member 2 and an ultrasonic receiver 5 arranged at one end of a receiver holding member 4. The two holding elements 2, 4 are connected to each other to ensure a constant distance 6 between the ultrasonic transmitter 3 and the ultrasonic receiver 5. The ultrasonic transmitter 3 and the ultrasonic receiver 5 are designed as piezoelectric elements.

Both the transmitter holding element 2 and the receiver holding element 4 are linearly shaped and together form a fork-like shape.

The ultrasonic transmitter 3 emits ultrasonic waves into the liquid 10 to be analyzed. The ultrasonic receiver 5 receives the ultrasonic waves after the ultrasonic waves have passed through the liquid 10. The speed of sound in the liquid 10 can be determined from the duration of time required for the ultrasonic waves to be transmitted to be received. This sound speed accordingly gives an indication of the properties of the liquid 10, since the sound speed varies, for example, with the composition of the liquid 10.

Furthermore, two temperature sensors 11 are arranged on the transmitter holding element 2 and on the receiver holding element 4, which temperature sensors 11 are designed as platinum temperature measuring elements, for example PT 1000. The temperature of the liquid 10 can be determined by means of the temperature sensor 11 and is also taken into account when determining the speed of sound, since it depends inter alia on the temperature.

The dimensions of the holding elements 2, 4 must be chosen such that the duration between the emission and the reception of the ultrasound waves on the path through the liquid 10 is smaller than the duration between the emission and the reception of the ultrasound waves on the path through the holding elements 2, 4. The result of this is that the holding elements 2, 4 must have a certain minimum length.

The ultrasonic sensor device 1 of fig. 1 has the following disadvantages: due to the linear holding elements 2, 4, a large installation space is required, and therefore the ultrasonic sensor device 1 cannot be used or can only be used to a limited extent for applications in which only little space is available for installing the ultrasonic sensor device 1.

To address this issue, fig. 2 shows an exemplary ultrasound device 1 in a schematic view. The ultrasonic sensor device 1 of fig. 2 also has an ultrasonic transmitter 3 and an ultrasonic receiver 5, which are arranged at a constant distance 6 from one another. For example, the shortest distance between the ultrasonic transmitter 3 and the ultrasonic receiver 5 may be considered as the distance 6, but any other distance may be used as a reference. It is essential that the path covered by the ultrasound waves from the ultrasound transmitter 3 to the ultrasound receiver 5 must remain constant.

The ultrasound transmitter 3 is arranged on the transmitter holding element 2, with which transmitter holding element 2 the ultrasound transmitter 3 is fastened on the housing 22 of the ultrasound sensor device 1 by means of a connecting unit 23. Furthermore, the transmitter holding element 2 is used for data transmission with the ultrasound transmitter 3.

The ultrasonic receiver 5 is arranged on a receiver holding element 4, with which receiver holding element 4 the ultrasonic receiver 5 is fastened on a housing 22 of the ultrasonic sensor device 1 by means of a connecting unit 23. Furthermore, the receiver holding element 4 is used for data transmission with the ultrasonic receiver 5.

Both the transmitter holding element 2 and the receiver holding element 4 are helical. The two holding elements 2, 4 each have 2.5 turns, wherein the number of turns is considered as an example and the invention is not limited to a specific number of turns. Due to the helical formation of the holding elements 2, 4, the path through the holding elements 2, 4 is significantly lengthened compared to a linear holding element with the same outer dimensions (see fig. 1). The helical shaping of the holding elements 2, 4 thus enables a miniaturization of the ultrasonic sensor device 1, since smaller outer dimensions are sufficient for the same path through the holding elements 2, 4.

Furthermore, the ultrasonic sensor device 1 has a stabilizing element 7. Centrally, an annular stabilizing element 7 is arranged, which is radially connected to the housing 22 by four further stabilizing elements 7.

The stabilizing element 7 serves to fix the holding elements 2, 4, so that vibrations are prevented and the distance 6 is always kept constant with high reliability. The stabilizing element 7 is arranged in such a way that flow restrictions are avoided as much as possible and no turbulence is generated.

The holding elements 2, 4 and the stabilizing element 7 are arranged in a plane arranged perpendicular to the main flow direction 9 of the liquid 10 to be analyzed.

Furthermore, the ultrasonic sensor device 1 has two temperature sensors 11, which are arranged in the region of the ultrasonic transmitter 3 and the ultrasonic receiver 5, and a pressure sensor 8 (see fig. 3), which is arranged perpendicular to the main flow direction 9.

Fig. 3 shows the ultrasonic sensor device of fig. 2 in a sectional view along line a-a in fig. 2. The housing 22 has an inlet 24 and an outlet 25, through which inlet 24 and outlet 25, respectively, the liquid 10 to be analyzed can flow in or out. The liquid 10 flows inside the ultrasonic sensor device 1 in the main flow direction 9.

As is further evident in fig. 3, the pressure sensor 8 is arranged on the housing 22 upstream of the ultrasonic transmitter 3 and the ultrasonic receiver 5, perpendicular to the main flow direction 9.

Fig. 4 and 5 show a further embodiment variant of the ultrasonic sensor device 1. In contrast to the embodiment variants shown in fig. 2 and 3, only the ultrasonic transmitter 3 is arranged on the spiral-shaped transmitter holding element 2, while the ultrasonic receiver 5 is arranged on the linear receiver holding element 4. Alternatively, the ultrasonic receiver 5 may also be arranged on the spiral-shaped receiver holding element 4, while the ultrasonic transmitter 3 is arranged on the linear transmitter holding element 2. Furthermore, no stabilizing elements 7 are provided in this embodiment variant, but they may alternatively be implemented.

Fig. 5 shows the ultrasonic sensor device of fig. 4 in a sectional view along line B-B in fig. 4.

Fig. 6 shows an exemplary refrigeration circuit 12 in a schematic view. The refrigeration circuit 12 has a compressor 13 and, viewed in the main flow direction 9, a condenser 14, an expansion valve 15 and an evaporator 16. A collection and drying unit 20 is associated with the condenser 14, wherein the collector and the dryer may also be formed as separate components.

Another optional component is an internal heat exchanger 17. The internal heat exchanger has a chamber 18 for liquid refrigerant, through which liquid refrigerant flows downstream of the condenser 14 and upstream of the expansion valve 15, and a chamber 19 for gaseous refrigerant, through which gaseous refrigerant flows downstream of the evaporator 16 and upstream of the compressor 13.

Furthermore, the refrigeration circuit 12 has an ultrasonic sensor device 12, which can be designed according to fig. 2 and 3 or 4 and 5. The transmitter holding element and/or the receiver holding element 4 of the ultrasonic sensor device 1 is/are meandering or spiral-shaped.

In the embodiment shown in fig. 6, the ultrasonic sensor device 1 is arranged downstream of the chamber 18 of liquid refrigerant of the internal heat exchanger 17 and upstream of the expansion valve 15.

In a further embodiment variant shown in fig. 7, the ultrasonic sensor device 1 is arranged downstream of the condenser 14 and upstream of the chamber 18 of liquid refrigerant of the internal heat exchanger 17, compared to fig. 6.

In a further embodiment variant shown in fig. 8, the ultrasonic sensor device 1 is arranged in a collecting and drying unit 20, in contrast to fig. 6 and 7. For example, as shown in fig. 9, the ultrasonic sensor device 20 may be disposed in a lower region (shown by a dotted line) of the collection and drying unit 20.

Fig. 10 shows a vehicle 21 with a refrigeration circuit 12, which has an ultrasonic sensor device 1. The refrigeration circuit 12 may be designed as described in, for example, fig. 6, 7 and 8. The vehicle 21 may be a passenger car, which is optionally designed as an electric vehicle.

List of reference numerals

1 ultrasonic sensor device

2 emitter holding element

3 ultrasonic transmitter

4 receiver holding element

5 ultrasonic receiver

6 distance

7 stabilizing element

8 pressure sensor

9 main direction of flow

10 liquid

11 temperature sensor

12 refrigeration circuit

13 compressor

14 condenser

15 expansion valve

16 evaporator

17 internal heat exchanger

18 Chamber for liquid refrigerant

19 Chamber for gaseous refrigerant

20 collecting and drying unit

21 vehicle

22 casing

23 connecting unit

24 inlet

25 outlet port