Refrigeration system with expansion tank and lubricant separator and motor vehicle with such a refrigeration system

Abstract

A refrigeration system (10) for a motor vehicle (200) powered by an internal combustion engine and / or an electric motor is described, comprising a refrigerant circuit (12) which includes: a refrigerant compressor (14); a first heat exchanger (16), in particular a condenser or gas cooler; a second heat exchanger (18), in particular an evaporator; a refrigerant receiver (20); wherein the refrigerant compressor (14), the first heat exchanger (16), the second heat exchanger (18) and the refrigerant receiver (20) are integrated into a main flow line (12h) of the refrigerant circuit (12) and are actively supplied with refrigerant; and an expansion tank (24) which is connected to the main flow line (12h) by means of an expansion line (26).It is provided that a separator (30) is arranged in the compensating line (26) between the main flow line (12h) and the expansion tank (24), which is designed to separate lubricants from a refrigerant-lubricant mixture, either predominantly or completely, so that refrigerant in the gas phase enters the expansion tank (24), either predominantly or completely. Furthermore, a motor vehicle (200) with such a refrigeration system (10) is described.

Description

[0001] The invention relates to a refrigeration system for a motor vehicle powered by an internal combustion engine and / or an electric motor vehicle, comprising a refrigerant circuit comprising: a refrigerant compressor; a first heat exchanger, in particular a condenser or gas cooler; a second heat exchanger, in particular an evaporator; a refrigerant receiver; wherein the refrigerant compressor, the first heat exchanger, the second heat exchanger and the refrigerant receiver are integrated into a main flow line of the refrigerant circuit and are actively supplied with refrigerant; and an expansion tank, which is connected to the main flow line by means of an expansion line.

[0002] Such a refrigeration system is known, for example, from DE 10 2015 006 189 A1. Reference is also made to US 2011 0 094 247 A1, US 5 575 833 A and CN 209 672 624 U.

[0003] Expansion tanks for transferring refrigerant from the main flow line of refrigeration systems are positioned to allow a refrigerant-lubricant mixture to flow into the tank, with the tank's outlet typically located at its lowest point. The tank's connection is usually chosen so that, when installed in the vehicle, the main flow line is lower than the expansion tank's outlet. Consequently, the required installation space, particularly in the vehicle's vertical direction, is increased. This results in refrigerant or refrigerant-lubricant mixture, and especially lubricant alone, flowing from the expansion tank into the main flow line when the refrigeration system is not in operation.During operation of the refrigeration system, an advantageous component arrangement prevents backflow, particularly of lubricant, into the expansion tank and simultaneously facilitates its overflow / backflow into the main line. Furthermore, depending on its design and position in the vehicle, but especially within the refrigeration system, the expansion tank can act as a lubricant trap, potentially leading to a lubricant shortage during operation.

[0004] The object underlying the invention is seen as being to provide a refrigeration system with an expansion tank in which the above disadvantages are avoided, in particular an improved refrigerant compensation can be provided.

[0005] This problem is solved by a refrigeration system and a motor vehicle with the features of the respective independent patent claim. Advantageous embodiments with expedient further developments are specified in the dependent patent claims.

[0006] The proposed refrigeration system for a combustion engine and / or electrically powered motor vehicle comprises a refrigerant circuit with: a refrigerant compressor; a first heat exchanger, in particular a condenser or gas cooler; a second heat exchanger, in particular an evaporator; a refrigerant receiver; wherein the refrigerant compressor, the first heat exchanger, the second heat exchanger and the refrigerant receiver are integrated into a main flow line of the refrigerant circuit and are actively supplied with refrigerant; and an expansion tank, which is connected to the main flow line by means of an expansion line.It is provided that a separator device is arranged in the compensating line between the main flow line and the compensating tank, which is designed to separate lubricants from a refrigerant-lubricant mixture mostly or completely, so that mostly or completely refrigerant in the gas phase enters the compensating tank.

[0007] This ensures that, regardless of the expansion tank's installation position relative to the main flow line, the majority or even the entire gas phase of the refrigerant enters the expansion tank. The lubricant remains at the separator and is available, particularly in the main flow line, because no lubricant transfer occurs. Therefore, any positioning and design of the expansion tank is possible.

[0008] The separator is advantageously positioned close to the main line in order to minimize the potential oil accumulation volume between the main line branch and the separator element. In particular, the separator can be directly connected to a branch provided on the main line. Alternatively, the switchable valve assembly can also be arranged upstream of the separator element.

[0009] In refrigeration systems, the separator can have a gas-permeable separator element with a lubricant-repellent structure. This improves the separation of the lubricant and the gaseous refrigerant, with the lubricant adhering little or not at all to the separator element.

[0010] In a refrigeration system, the separator element can be taller than the diameter of the equalizing line, such that the refrigerant-lubricant mixture entering the separator impacts the separator element and deflects the refrigerant gas phase upwards against gravity, separating the lubricant in the direction of gravity. This creates a height difference or level difference within the confined space of the separator, allowing the lubricant, with its higher specific gravity, to separate from the refrigerant-lubricant mixture, even by gravity.

[0011] In the refrigeration system, the expansion line downstream of the separator can be connected to the expansion tank at any point, particularly at its bottom, top, or a side wall. Such an arbitrary connection is possible because the separator is designed so that the expansion tank itself does not necessarily have to perform a separating function and therefore does not have to be responsible for returning accumulated lubricant to the main line.

[0012] In refrigeration systems, the expansion tank can be designed with a funnel shape on its underside, allowing any lubricant that passes through the separator to be collected. This optional design ensures that any lubricant that may enter the expansion tank can be separated and, if necessary, added back in when refrigerant is drawn from the tank.

[0013] A motor vehicle with an internal combustion engine and / or electric drive can be equipped with a refrigeration system as described above.

[0014] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. These show: Fig. 1. A simplified and schematic representation of a refrigeration system with a separator in a motor vehicle; Fig. 2 a simplified and schematic representation of a separation device of the refrigeration system.

[0015] In Fig. Figure 1 shows a simplified and schematic circuit diagram of a refrigeration system 10 of a motor vehicle 200. The refrigeration system 10 is shown here only as a so-called AC system. It should be noted that the following description is also applicable and transferable to more complex refrigeration systems 10, such as those with air and / or water heat pump functionality and the integration of additional heat exchangers, valves, etc.

[0016] The refrigeration system 10 has a refrigerant circuit 12. The refrigerant circuit 12 comprises a refrigerant compressor 14, a first heat exchanger 16, in particular a condenser or gas cooler, a second heat exchanger 18, in particular an evaporator, and a refrigerant receiver 20. In the example shown, the refrigerant receiver 20 is combined with an internal heat exchanger 22. However, it is also conceivable to provide the refrigerant receiver 20 and an internal heat exchanger 22 separately.

[0017] The refrigerant compressor 14, the first heat exchanger 16, the second heat exchanger 18 and the refrigerant collector 20 are integrated into a main flow line 12h of the refrigerant circuit 12 and are actively supplied with refrigerant during refrigeration system operation.

[0018] The refrigeration system 10 also includes an expansion tank 24, which is connected to the main flow line 12h by means of an expansion line 26. The transition from the main flow line 12h to the expansion line 26 is illustrated by the branch Ab1.

[0019] An expansion tank 24 can be of any shape and design, thus extending in all three spatial axes, and therefore oriented both horizontally and vertically. Its at least one connection point, i.e., the interface to the expansion line 26 and thus to the main flow line 12h, is preferably located at the lowest point of the expansion tank 24.

[0020] In the expansion line 26, a separator 30 is arranged between the main flow line 12h or the branch Ab1 and the expansion tank 24. The separator 30 is designed to separate lubricants from a refrigerant-lubricant mixture, either predominantly or completely, so that refrigerant in the gas phase enters the expansion tank 24 predominantly or completely. The expansion tank 26 is partially filled during operation of the refrigeration system 10, but especially after shutdown, i.e., when the refrigeration system 10 is inactive. Emptying, on the other hand, occurs predominantly during start-up and thus when the static pressure level of the refrigeration system 10 drops to a low-pressure level. Fig. Figure 1 shows the separation device 30 in a highly simplified form as a rectangle.

[0021] The compensating line 26 is designed as a branch line to the main flow line 12h. In other words, the compensating line 26 is passively integrated into the refrigerant circuit 12, i.e., it is not actively permeated by refrigerant during refrigeration system operation.

[0022] Fig. Figure 2 shows a simplified and schematic enlarged view of the separation device 30.

[0023] The separating device 30 has an inlet-side pipe section 32 and an outlet-side pipe section 34. The two pipe sections 32 and 34 are in the Fig. 2 shown schematically, where their length and diameter are not shown to scale.

[0024] The separator 30 has a gas-permeable separator element 36 which has a lubricant-repellent structure. The separator element 36 can be designed like a filter with sufficiently small pores so that lubricant droplets are retained, but refrigerant in the gas phase can pass through.

[0025] The separating element 36 can have a greater height AH than a diameter DM of the compensating line 26, such that the refrigerant-lubricant mixture KSG entering the separating device 30 impacts the separating element 36 and the gas phase of the refrigerant GK is deflected upwards against gravity, separating the lubricant SM in the direction of the acting gravity.

[0026] The lubricant SM retained or separated by the separator device 30 is therefore available at all times for the actively flowing refrigerant circuit 12 or the main flow line 12h in order to ensure sufficient lubrication, in particular of the refrigerant compressor 12.

[0027] Here it may prove advantageous if the separating device 30 is provided near the branch point Ab1 to the main flow line 12h in order to keep the volume for a developing oil reservoir small, or / and is placed (slightly) offset upwards in the vertical direction to the main flow line 12h in order to support a return flow of separated oil and make it available again to the main flow.

[0028] From the Fig. It is further evident from Figure 2 that the compensating line 26 can be connected to the compensating tank 24 at any point downstream of the separating device 30 or downstream of its outlet-side line section 34. In particular, the compensating line 26 can preferably be connected to the compensating tank 24 at an underside US, an upper side OS, or a side wall SW.

[0029] By providing the separator device 30 upstream of the expansion tank 24, it is therefore possible to arrange the connection with the expansion line 26 at virtually any point or position of the expansion tank 24. This also allows the installation position of the expansion tank 24 within the available installation space in the motor vehicle 200 to be optimized, in particular because the expansion tank 24, while preferably, no longer necessarily has to be located higher than the main flow line 12h of the refrigeration system 10.

[0030] In the case of a connection of the compensating line 26 to a bottom surface US of the expansion tank 24, it is optionally also possible for the expansion tank 24 to be funnel-shaped on its bottom surface US, which in Fig.2 is simplified as a dotted line, such that a lubricant component passing through the separator 30 can be collected therein and thus removed, particularly when starting a refrigeration system 10.

[0031] As mentioned above, a motor vehicle 200 with internal combustion engine and / or electric drive can be equipped with a refrigeration system 10 described above with a separator device 30. 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 2015 006 189 A1

[0002] US 2011 0 094 247 A1

[0002] US 5,575,833 A

[0002] CN 209 672 624 U

[0002]

Claims

[1] Refrigeration system (10) for a motor vehicle (200) powered by an internal combustion engine and / or an electric motor, comprising a refrigerant circuit (12) comprising: a refrigerant compressor (14); a first heat exchanger (16), in particular a condenser or gas cooler; a second heat exchanger (18), in particular an evaporator; a refrigerant collector (20); wherein the refrigerant compressor (14), the first heat exchanger (16), the second heat exchanger (18) and the refrigerant receiver (20) are integrated into a main flow line (12h) of the refrigerant circuit (12) and are actively supplied with refrigerant; a compensating reservoir (24) which is connected to the main flow line (12h) by means of a compensating line (26); characterized by , that In the compensating line (26) between the main flow line (12h) and the expansion tank (24) a separating device (30) is arranged which is designed to separate lubricant (SM) from a refrigerant-lubricant mixture (KSG) mostly or completely, so that mostly or completely refrigerant in the gas phase (GK) enters the expansion tank (24). [2] Refrigeration system (10) according to claim 1, characterized by , that the separating device (30) has a gas-permeable separating element (36) which has a lubricant-repellent structure. [3] Refrigeration system (10) according to claim 2, characterized by, that the separating element (36) has a greater height (AH) than a diameter (DM) of the compensating line (26), such that refrigerant-lubricant mixture (KSG) entering the separating device (30) impacts the separating element (36) and the gas phase of the refrigerant (GK) is deflected upwards against gravity, separating the lubricant (SM) in the direction of the acting gravity. [4] Refrigeration system (10) according to any of the preceding claims, characterized by , that the compensating line (26) is connected downstream of the separating device (30) to the compensating tank (24) at any point therein, in particular at its underside (US) or at its top (OS) or at a side wall (SW). [5] Refrigeration system (10) according to any of the preceding claims, characterized by, that the expansion tank (24) is designed in a funnel shape on its underside (US) such that a portion of the lubricant that has passed through the separating device (30) can be collected in it. [6] Motor vehicle (200) with internal combustion engine and / or electric drive and with a refrigeration system (10) according to one of the preceding claims.

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