A method for maximizing the refrigerant in the working system section of a refrigeration device, the refrigeration device itself, and a motor vehicle equipped with such a refrigeration device.

Abstract

The present invention relates to a method (500) for operating a refrigeration device (10) for a motor vehicle, wherein the refrigeration device (10) includes: a refrigerant compressor (12) connected to or capable of being connected to a primary branch (14) and a secondary branch (16); a primary branch valve (A4) disposed between the refrigerant compressor (12) and an external heat exchanger (18); a secondary branch valve (A3) disposed between the refrigerant compressor (12) and another heat exchanger, particularly a heating regulator (26), which serves as a heat source; and at least one valve device (A2, A5) disposed between a high-pressure side section (15, 15a) of the primary branch (14) or the secondary branch (16) and a low-pressure side section located upstream of the refrigerant compressor (12). The method (500) includes the following steps: setting (S502) an operating mode of the refrigeration equipment, wherein the primary branch (14) is working while the secondary branch (16) is not working, or the secondary branch (16) is working while the primary branch (14) is not working; obtaining (S503) the pressure (p_inak) in the non-working branch (14, 16); and activating the suction of the refrigerant from the non-working branch (14, 16) to the working branch (14, 16) by reducing (S506) the pressure (pA) in the working branch (14, 16) to a value lower than the pressure (p_inak) in the non-working branch (14, 16) and by opening the valve devices (A2, A5).

Description

Technical Field

[0001] The present invention relates to a method for maximizing the refrigerant in the working system section / activation system section of a motor vehicle refrigeration equipment, a refrigeration equipment, and a motor vehicle having such a refrigeration equipment. Background Technology

[0002] In particular, refrigeration equipment that can also have heat pump functionality typically includes: a refrigerant compressor connected or potentially connected to a primary branch / main branch and a secondary branch / auxiliary branch; an external heat exchanger acting directly or indirectly, arranged in the primary branch; an evaporator arranged in the primary branch; at least one additional heat exchanger serving as a heat source, particularly a heating regulator, arranged in the secondary branch; a primary branch valve arranged between the refrigerant compressor and the external heat exchanger; and a secondary branch valve arranged between the refrigerant compressor and at least one additional heat exchanger, particularly a heating regulator.

[0003] For example, refrigeration equipment is known from DE 10 2011 118 162 A1 or DE 10 2019 201 427 A1, in which the refrigerant can flow from a non-working area or a non-working branch into the working area or working branch. A refrigeration equipment is known from DE 10 2013 019 498 A1, in which a computational model is used for refrigerant management. In the known refrigeration equipment, the refrigerant is drawn from the non-working area based on the operating pressure typically encountered during operation, and this aspect has not received particular attention.

[0004] It has been shown that in refrigeration equipment operating as described in the literature according to the prior art, the amount of refrigerant may be rarely monitored, which may result in the refrigeration equipment or system operating with insufficient filling (in the working area or working branch), which may lead to power loss of the refrigeration equipment under different operating conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a method for optimizing refrigerant management, particularly when considering different operating states of refrigeration equipment.

[0006] This objective is achieved by a method, a refrigeration device, and a motor vehicle having the features described in the respective independent claims. Advantageous design solutions with suitable improvements are given in the dependent claims.

[0007] A method for operating a refrigeration device for a motor vehicle is proposed, wherein the refrigeration device includes: a refrigerant compressor connected to or capable of connecting to a primary branch and a secondary branch; an external heat exchanger acting directly or indirectly, arranged in the primary branch; an evaporator arranged in the primary branch; at least one additional heat exchanger, particularly a heating regulator, serving as a heat source, arranged in the secondary branch; a primary branch valve arranged between the refrigerant compressor and the external heat exchanger; a secondary branch valve arranged between the refrigerant compressor and at least one additional heat exchanger, particularly a heating regulator, serving as a heat source; and at least one valve device arranged between a high-pressure side section of the primary or secondary branch and a low-pressure side section located upstream of the refrigerant compressor.

[0008] Here, the method includes the following steps:

[0009] A refrigeration equipment is configured to operate in a mode in which the primary branch is active / activated while the secondary branch is inactive / deactivated, or in which the secondary branch is active while the primary branch is deactivated; the pressure in the inactive / deactivated branch is obtained; and the refrigerant is activated / induced to be drawn from the non-active branch to the active branch by reducing the pressure in the active / activated branch to a value lower than the pressure in the non-active branch and by opening the valve device.

[0010] By acquiring the pressure in the non-operating branch or non-operating section of the refrigeration equipment, the extraction of refrigerant from the non-operating branch can be intentionally activated, while the pressure in the operating branch can be intentionally reduced. It should be noted that the term "detection or acquisition" of pressure, as used herein, can refer to direct pressure measurement or indirect pressure estimation, particularly based on other parameters such as refrigerant temperature, refrigerant characteristics, and other operating parameters of the refrigeration equipment, such as the refrigerant compressor. That is, the term "detection / acquisition" refers to obtaining a pressure value that can be based on a specific measurement or derived, calculated, or estimated from other characteristic parameters.

[0011] In this method, the pressure in the working branch can be reduced from a working pressure level that is higher than the pressure in the non-working branch. This achieves, at least temporarily, a drastic reduction in the pressure in the working branch such that refrigerant can be drawn from the non-working branch to maximize the amount of refrigerant in the working area of ​​the refrigeration equipment, before subsequently restoring it to the actual working pressure level.

[0012] In this method, the pressure in the working branch can be further reduced from a working pressure level lower than that in the non-working branch. This achieves, at least temporarily, a further reduction in the pressure in the working branch, thereby accelerating the extraction of refrigerant from the non-working branch or maximizing the amount of refrigerant in the working area.

[0013] In order to ensure the operation and performance of the refrigeration equipment regardless of the fact that the activating refrigerant is extracted from the inactive branch, the pressure in the working branch can be maintained at a pressure level equivalent to the low pressure limit permissible for the refrigeration equipment.

[0014] In the method, the pressure value acquired or estimated in the non-working branch can be compared with the static pressure (Ruhedruck) that occurs at the current ambient temperature or the current cooling medium temperature / cooling fluid temperature, wherein the extraction of the refrigerant from the non-working branch is activated only when the acquired pressure is greater than or equal to the static pressure that occurs at the ambient temperature.

[0015] In particular, extraction needs can be determined, identified, or predicted using pressure sensors installed in non-operating branches or dead zones. If the pressure value obtained in a non-operating branch or non-operating section is (consistently) lower than the static pressure at ambient temperature or coolant / cooling fluid temperature, then the branch has been extracted and only gaseous refrigerant remains. If the pressure value obtained in a non-operating branch or non-operating section is equal to or higher than the static pressure at the corresponding detected or measured ambient temperature or coolant / cooling fluid temperature, then the branch or section has not been extracted and the refrigerant exists as a two-phase mixture or may also exist in a liquid state. The relationship between (ambient / fluid) temperature and refrigerant pressure can be derived, for example, from the material data sheet for the refrigerant used.

[0016] In this method, refrigerant can be extracted from non-operating branches when the refrigeration equipment starts up or restarts, thereby maximizing the amount of refrigerant in the operating branches. This allows the refrigeration equipment to reach optimal power very quickly in a defined operating mode and advantageously influences the amount of refrigerant in the operating branches from the start of operation.

[0017] Furthermore, a refrigeration device for motor vehicles, particularly one with a heat pump function, is provided. The refrigeration device includes: a refrigerant compressor connected to or capable of connecting to a primary branch and a secondary branch; an external heat exchanger acting directly or indirectly, arranged in the primary branch; an evaporator arranged in the primary branch; at least one additional heat exchanger serving as a heat source, particularly a heating regulator, arranged in the secondary branch; a primary branch valve arranged between the refrigerant compressor and the external heat exchanger; and a valve arranged in the refrigerant compressor... A secondary branch valve between the compressor and at least one other heat exchanger, particularly a heating regulator, serving as a heat source; at least one valve device arranged between the high-pressure side section of the primary or secondary branch and the low-pressure side section located upstream of the refrigerant compressor; and at least one pressure sensor or pressure / temperature sensor arranged in the corresponding high-pressure side section of the primary or secondary branch and configured to detect pressure in the non-operating branch during operation when the primary branch is operating and the secondary branch is not operating, or during operation when the secondary branch is operating and the primary branch is not operating.

[0018] The refrigeration equipment may include a control device configured to perform the methods described above.

[0019] Motor vehicles, especially those operating at least partially on ground power, may have the refrigeration equipment described above. In electric vehicles, the effective operation of the refrigeration equipment can achieve current savings, thereby enabling a greater driving range.

[0020] In general, it should be noted that the method described above can be used for any type of refrigeration equipment having a system that is segmentable. That is, the method can be used not only for simple refrigeration equipment but also for systems with heat pump and / or reheating functions, thus allowing for the targeted and active utilization of the associated advantages. As a simplest variation, for example, a refrigeration equipment can be seen having a second evaporator branch in the form of a chiller or an air-loaded evaporator, wherein this additional branch or the second branch itself can also be shown segmentally. Attached Figure Description

[0021] Other advantages and details of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

[0022] in:

[0023] Figure 1 A schematic and simplified circuit diagram of a refrigeration device for a motor vehicle is shown.

[0024] Figure 2 This was shown, especially by means of in Figure 1 A flowchart of an exemplary implementation of the method performed by the refrigeration equipment described herein. Detailed Implementation

[0025] exist Figure 1 An embodiment of a refrigeration device 10 for a motor vehicle is illustrated schematically and in a simplified manner. The refrigeration device 10 includes a refrigerant circulation loop 11, which can operate not only in refrigeration device operation (also simply referred to as AC-operation) mode but also in heat pump mode. In the illustrated embodiment, the refrigeration device 10 includes a refrigerant compressor 12, an external heat exchanger 18, an internal heat exchanger 20, an evaporator 22, and a storage unit or refrigerant collector 24. The external heat exchanger 18 can be configured as a condenser or a gas cooler. In particular, the external heat exchanger 18 in the illustrated embodiment can be bidirectionally flowed.

[0026] Evaporator 22 is shown here, for example, as a front evaporator for a vehicle. Evaporator 22 may also refer to other possible evaporators in a vehicle, such as front evaporators, which may be arranged in parallel with each other in terms of flow technology. In other words, the refrigeration device 10 includes at least one evaporator 22.

[0027] A shut-off valve A4 is installed downstream of compressor 12. An expansion valve AE2 is installed upstream of evaporator 22.

[0028] Within the scope of this specification, the section from the compressor 12 to the external heat exchanger 18, to the internal heat exchanger 20, and to the evaporator 22 in the entire refrigerant circulation loop 11 of the refrigeration equipment 10 is referred to as the primary branch 14.

[0029] The refrigeration equipment 10 also includes a heating regulator 26 (also known as a heated condenser or heated gas cooler). A shut-off valve A3 is arranged upstream of the heating regulator 26. A shut-off valve A4 is arranged downstream of the heating regulator 26. In addition, an expansion valve AE4 is arranged downstream of the heating regulator 26.

[0030] Within the scope of this specification, the section from compressor 12 to heater 26, to expansion valve AE4, and to branch point Ab2 in the entire refrigerant circulation loop of refrigeration equipment 10 is referred to as secondary branch 16. Secondary branch 16 includes heating branch 16.1, which extends from shut-off valve A3 via heater 26 to shut-off valve A1. Furthermore, secondary branch 16 also includes a reheat branch or reheat branch 16.2, which is fluidly connected upstream to heater 26 and downstream to external heat exchanger 18. Here, secondary branch 16 or reheat branch 16.2 connects to primary branch 14 at branch point Ab2.

[0031] The refrigeration unit 10 includes an additional evaporator or chiller 28. The chiller 28 is configured to be connected in parallel with the evaporator 22 in terms of flow technology. The chiller 28 can be used, for example, to cool the electrical components of a vehicle, but can also be used to implement a water-heat pump function when using the waste heat of at least one electrical component. An expansion valve AE1 is connected upstream before the chiller 28.

[0032] The refrigeration unit 10 may also include an electric heating element 30, which may be implemented, for example, as a high-pressure PTC heating element. The electric heating element 30 serves as an additional heater for the input airflow L introduced into the vehicle's interior space. Here, the electric heating element 30 may be installed in the air conditioning unit 32 together with the heating regulator 26 and the evaporator 22. Here, the electric heating element 30 may be arranged to be connected downstream of the heating regulator 26.

[0033] exist Figure 1 Check valves R1 and R2 can also be seen. Additionally, sensors pT1 to pT5 for detecting the pressure and / or temperature of the refrigerant medium are shown. It should be noted that the number of sensors and their arrangement are shown here merely as an example. The refrigeration unit 10 may also have fewer or more sensors. In the example shown, combined pressure / temperature sensors pT1 to pT5 are shown as sensors. However, it is also conceivable to use sensors that are separate from each other to measure pressure or temperature, and if necessary, the sensors may also be arranged spatially separate from each other along the refrigerant medium piping.

[0034] The refrigeration equipment 10 can operate in different modes, which are briefly described below.

[0035] In AC-operation mode of the refrigerant circulation loop 11, with shut-off valve A4 open, the refrigerant compressed to high pressure flows from the refrigerant compressor 12 into the external heat exchanger 18. From this external heat exchanger, the refrigerant flows to the high-pressure section of the internal heat exchanger 20 and to the fully open expansion valve AE3. Through branch point Ab1, the refrigerant can flow to expansion valve AE2 and into the internal evaporator 22 (evaporator section 22.1). Alternatively or in parallel, the refrigerant can flow through branch point Ab4 and expansion valve AE1 into the chiller 28 (chiller section 28.1). From the evaporator 22 and / or chiller 28, the refrigerant flows from the evaporator 22 and / or chiller 28 into the collector 24 on the low-pressure side and returns to the compressor 12 through the low-pressure section of the internal heat exchanger 20.

[0036] In AC-operation mode, the heating branch 16.1 or secondary branch 16 is shut off by means of the shut-off valve A3, so that the hot refrigerant cannot flow through the heating regulator 26. In order to recover the refrigerant from the inactive / non-operating heating branch 16.1, the shut-off mechanism A5, which is configured as a shut-off valve, can be opened, so that the refrigerant—while the shut-off mechanism A2 is closed at the same time—can flow through the shut-off mechanism A5 and the check valve R2 toward the collector 24.

[0037] In the heating operation mode of the refrigerant circulation loop 11, the shut-off valve A4 is closed and the shut-off valve A3 is opened, so that the hot refrigerant can flow into the heating branch 16.1.

[0038] To perform the heating function using chiller 28 to achieve water-heat pump operation mode, refrigerant compressed by refrigerant compressor 12 flows into heater regulator 26 through open shut-off valve A3. At heater regulator 26, heat is output to the input airflow L directed into the vehicle interior space. The refrigerant then flows through open shut-off valve A1 and branch point Ab1. By means of expansion valve AE1, the refrigerant expands into chiller 28 to absorb waste heat from electrical and / or electronic components arranged in cooling medium circulation loop 28.2. In this heating function, expansion valves AE3 and AE4 are closed, shut-off valve A5 is closed, and shut-off valve A2 is open. At this time, the refrigerant transferred in water-heat pump operation mode can be drawn from bidirectional branch 14.1 or primary branch 14 through shut-off valve A2 and delivered to collector 24 through check valve R2.

[0039] To perform the heating function using the external heat exchanger 18, which acts as the evaporator of the heat pump, refrigerant compressed by the refrigerant compressor 12 flows into the heating regulator 26 through the open shut-off valve A3 to output heat to the input air flow L. Next, the refrigerant expands through the open shut-off valve A1 into the external heat exchanger 18 using the expansion valve AE3 to absorb heat from the ambient air. Subsequently, the refrigerant flows through the heat pump recirculation branch 15 to the collector 24 and back to the refrigerant compressor 12. Here, expansion valves AE1, AE2, and AE4 remain closed, just like the shut-off valve A5.

[0040] An indirect triangular connection can be achieved by expanding the refrigerant compressed by the refrigerant compressor 12 into the chiller 28 via the expansion valve AE1 when the shut-off valve A1 is open. Simultaneously, no mass flow is generated on the cooling medium side, i.e., in the cooling medium circulation loop 28.2. Specifically, the fluid used as the cooling medium, such as water or a water-glycol mixture, remains on the cooling medium side of the chiller 28; more precisely, the chiller 28 is not activated and therefore not circulated by the cooling medium. In this switching variant, expansion valves AE2, AE3, and AE4 remain closed.

[0041] During reheating or reheating operation, the input airflow L delivered to the vehicle interior is first cooled and dehumidified by means of the evaporator 22. Using the heat transferred to the refrigerant through evaporation and dehumidification, as well as the heat transferred to the refrigerant through the compressor 12, the input airflow L can be fully or at least partially reheated by means of the heating regulator 26.

[0042] For this purpose, the refrigeration unit 10, especially the air conditioning unit 32, has an adjustable, especially controllable and swingable temperature valve 34 between the evaporator 22 and the heating regulator 26. In the example shown, temperature valves 34L and 34R are arranged on the left and right sides (in... Figure 1 (Illustrated schematically). Temperature valves 34L and 34R can be adjusted or oscillated between an open position, also known as the 100% position, and a closed position, also known as the 0% position. Alternatively, temperature valves 34L and 34R can be connected downstream of the heating regulator 26.

[0043] In the 100% position, the entire input airflow L of the cross-flow evaporator 22 flows through the heater regulator 26 and is heated, after which the input airflow can flow into the vehicle's passenger compartment. In the 0% position, the entire input airflow L of the cross-flow evaporator 22 flows into the passenger compartment without being heated and thus without absorbing heat, bypassing the heater regulator 26.

[0044] In the x position (where 0% < x < 100%) of temperature valves 34L and 34R, the temperature valves are only partially open, so that only a portion of the input airflow L through the evaporator 22 flows through the heater regulator 26. This heated portion of the airflow can then be mixed with the remaining, cooled, and dehumidified portion. The input airflow L heated in this way is delivered to the vehicle's passenger compartment. For example, the 50% position indicates that temperature valves 34L and 34R are only half open, i.e., 50%.

[0045] The refrigeration unit 10 has a sensor device 36 in the secondary branch 16, downstream of the secondary branch valve A3 and upstream of the heating regulator 26. This sensor device is configured to detect the hot gas temperature value, reflecting the temperature of the gaseous refrigerant, downstream of the heating regulator 26. Here, the hot gas temperature value can be directly measured or detected, or it can be estimated indirectly based on other system parameters. For example, it is conceivable to determine the pressure in the secondary branch 16 by means of the sensor device 36 and derive the hot gas temperature value from it. The sensor device 36 can be, for example, a simple temperature sensor or a combined temperature / pressure sensor.

[0046] In principle, the method proposed herein can be applied to each of the operating modes described above, such as AC-operating mode and heating operating modes with / without heat pump function, wherein it is assumed that either primary branch 14 or secondary branch 16 is not activated and therefore not circulated by the refrigerant, that is, when primary branch valve A4 is closed or secondary branch valve A3 is closed, the primary branch or secondary branch is inactive / non-operating, respectively.

[0047] from Figure 1 As can be seen, a shut-off valve A2 is installed in the pipeline section 15. Here, the shut-off valve A2 is arranged in the high-pressure side of the primary branch 14, wherein the pipeline section 15 connects the primary branch 14 to the low-pressure side of the refrigerant circulation loop 11 upstream of the refrigerant compressor 12.

[0048] Furthermore, a shut-off valve A5 is installed in pipeline section 15a. Here, the shut-off valve A5 is arranged on the high-pressure side of the secondary branch 16, wherein pipeline section 15a connects the secondary branch 16 to the low-pressure side of the refrigerant circulation 11 upstream of the refrigerant compressor 12.

[0049] To determine the pressure in the corresponding non-operating branches 14, 16 or non-operating regions of the refrigerant circulation loop 11, corresponding sensor devices pT6 and pT7 are assigned to the primary branch 14 and the secondary branch 16, respectively. Here, sensor devices pT6 and pT7 can be pressure sensors or pressure / temperature sensors. The corresponding pressure sensors pT6 and pT7 are respectively arranged downstream of the primary branch valve A4 or the secondary branch valve A3. That is, the pressure sensors pT6 and pT7 are located downstream of the corresponding shut-off mechanisms A3 and A4 relative to the normal flow direction of the refrigerant, which are used to activate or deactivate the relevant branches 14 and 16.

[0050] Next reference Figure 2 To be more precise, method 500 can be used to purposefully extract refrigerant from a non-working area of ​​refrigeration equipment 10.

[0051] According to Figure 2The method 500 shown in the figure switches to the desired or suitable operating mode after the refrigeration equipment 10 is started (S501) during operation, as shown in step S502. According to step S503, the pressure p_inak is detected in the non-operating branch or non-operating area of ​​the refrigeration equipment 10. In step S504, it is checked whether the obtained pressure value p_inak is less than the static pressure pR that occurs at ambient temperature. If the pressure p_inak in the relevant branches 14, 16 is less than the static pressure pR, the method ends because further extraction from the non-operating branches 14, 16 is no longer needed or possible. If the detected pressure p_inak is greater than or equal to the static pressure pR, according to step S505, it is checked whether the operating pressure pA on the low-pressure side of the refrigerant circulation loop 11 is greater than the pressure p_inak obtained in the non-operating branches 14, 16.

[0052] If the working pressure pA is greater than the pressure p_inak, according to step S506, the working pressure pA is actively reduced to a value lower than the pressure p_inak. This can be done by actively manipulating the activated and thus flow-through components of the relevant branches 14 and 16, especially the associated valve devices, such as expansion valves AE1, AE2, and AE3, but also by actively manipulating the compressor 12 to temporarily achieve a lower working pressure pA. If the working pressure pA is lower than the pressure p_inak, according to step S507, it is checked whether the working pressure pA is greater than the low-pressure limit p_grenz. If the working pressure pA is higher than the low-pressure limit p_grenz, the working pressure pA is further actively reduced (S506) or can be further actively reduced (S506). If the working pressure pA reaches the low-pressure limit p_grenz, the working pressure pA is not further actively reduced and the working pressure is adjusted (S508) to a suitable value or maintained at the low-pressure limit p_grenz, as indicated by two arrows pointing upwards or downwards respectively. Although this is not explicitly shown in the process flow, method 500 certainly includes, where appropriate, opening the relevant valve device, in particular opening the shut-off valve A2 or A5, so that a draw-out connection can be established between the low-pressure side and the non-operating branches 14 and 16.

[0053] Combining the conditions in steps S505 and S506, namely, intentionally reducing the working pressure pA when it is higher in normal operation than the pressure p_inak in the non-working branch, can be referred to as or understood as the first mode of actively extracting the refrigerant. That is, the first mode results in forced extraction because automatic extraction based on the existing pressure ratio cannot be guaranteed during normal operation of the refrigeration equipment.

[0054] Combining the conditions in steps S507 and S506—that is, further reducing the working pressure pA even though it is already lower than the pressure p_inak in the non-working branch—can be termed or understood as a second mode of actively extracting the refrigerant. This second mode results in accelerated extraction of the refrigerant.

[0055] The application of the method will then be explained by way of example using several examples of different operating modes of the refrigeration equipment 10.

[0056] In the simple AC-operation mode (internal space cooling), with the secondary branch valve A3 closed and valves A1, AE1, and AE4 closed, the refrigerant actively flows from the refrigerant compressor 12 through the open primary branch valve A4, the external heat exchanger 18, and the evaporator 22 in the primary branch 14. Thus, on the low-pressure side, i.e., downstream of the evaporator 22, an operating pressure pA is formed, which is typically lower than the pressure p_inak obtained in the non-operating branch 16 by means of sensor pT6. Correspondingly, in this simple AC-operation mode, a second active suction mode is typically considered, in which the already lower operating pressure pA is further reduced so that more refrigerant is drawn from the non-operating branch 16 through the open shut-off valve A5.

[0057] In the heating operation mode with water heat pump function, when the primary branch valve A4 is closed and valves AE2, AE3, and AE4 are also closed, the refrigerant actively flows from the refrigerant compressor 12 through the open secondary branch valve A3, the heat exchanger 26 (heat regulator) which serves as the heat source, and the chiller 28 (water heat pump) in the secondary branch 16. Thus, a working pressure pA is formed on the low-pressure side, i.e., downstream of the chiller 28. This working pressure does not necessarily have to be less than the pressure p_inak obtained in the non-working branch 14 by means of sensor pT7. Accordingly, in this heating operation with water heat pump function, a first mode of active extraction is typically considered, in which the working pressure pA is actively reduced so that the refrigerant is extracted from the non-working branch 14 through the open shut-off valve A2.

[0058] In other operating states of the refrigeration equipment 10, such as in the so-called reheat or reheating operation mode, the refrigerant can also be actively extracted from the non-working branch, non-working area, or non-working section of the refrigeration equipment 10.

[0059] Therefore, in principle, in the method 500 presented herein, the low pressure level (working pressure pA) is actively and at least temporarily adjusted to be lower than or reduced to a pressure level below that of the non-working branch or non-working area.

[0060] In principle, extraction is only permitted when the pressure level on the working system side is lower than the pressure level on the non-working system side, and the following extraction condition is met:

[0061] p_ab <p_inak

[0062] Only then can the refrigerant be extracted, thereby transferring the refrigerant from the non-working branch or non-working system section to the working branch or working system section.

[0063] As mentioned at the beginning, it should also be noted that the method 500 described above can be used in any type of refrigeration equipment having a system that has segmentable sections. That is, the method can be used not only in purely refrigeration equipment but also in the system 10 with heat pump and / or reheating functions exemplarily described herein, thereby allowing for the purposeful and proactive utilization of the associated advantages. As the simplest variation, for example, a refrigeration equipment can be seen having a second evaporator branch in the form of a chiller or an air-loaded evaporator, wherein this additional branch or the second branch itself is segmentable.

Claims

1. A method (500) for operating a refrigeration device (10) for a motor vehicle, wherein, Refrigeration equipment (10) includes: A refrigerant compressor (12) is connected to or can be connected to the primary branch (14) and the secondary branch (16); An external heat exchanger (18) that acts directly or indirectly is arranged in the primary branch (14); Evaporator (22), the evaporator is arranged in the primary branch (14); At least one additional heat exchanger serving as a heat source is arranged in the secondary branch (16); A primary branch valve (A4) is arranged between the refrigerant compressor (12) and the external heat exchanger (18); A secondary branch valve (A3) is arranged between the refrigerant compressor (12) and the other heat exchanger that serves as a heat source; At least one valve device (A2, A5) is arranged between the high-pressure side section (15, 15a) of the primary branch (14) or the secondary branch (16) and the low-pressure side section located upstream of the refrigerant compressor (12). The method (500) includes the following steps: Set (S502) an operating mode for the refrigeration equipment, wherein the primary branch (14) is working while the secondary branch (16) is not working, or wherein the secondary branch (16) is working while the primary branch (14) is not working; Get (S503) the pressure (p_inak) in the non-working branches (14, 16); By reducing (S506) the pressure (pA) in the working branches (14, 16) to a value lower than the pressure (p_inak) in the non-working branches (14, 16) and by opening the valve devices (A2, A5), the suction of the refrigerant from the non-working branches (14, 16) to the working branches (14, 16) is activated.

2. The method (500) according to claim 1, wherein, The other heat exchanger is a heating regulator (26).

3. The method (500) according to claim 1 or 2, wherein, The pressure (pA) in the working branches (14, 16) is reduced from the working pressure level, which is higher than the pressure in the non-working branches (14, 16) (S505).

4. The method (500) according to claim 1 or 2, wherein, The pressure (pA) in the working branches (14, 16) is further reduced from the working pressure level (p_inak) which is lower than the pressure (p_inak) in the non-working branches (14, 16) (S507).

5. The method (500) according to claim 3, wherein, The pressure (pA) in the working branches (14, 16) will be maintained (S509) at a pressure level equivalent to the low pressure limit (p_grenz) allowed for the refrigeration equipment.

6. The method (500) according to claim 4, wherein, The pressure (pA) in the working branches (14, 16) will be maintained (S509) at a pressure level equivalent to the low pressure limit (p_grenz) allowed for the refrigeration equipment.

7. The method (500) according to claim 1 or 2, wherein, The pressure value (p_inak) obtained in the non-working branch (14, 16) is compared with the static pressure (pR) that occurs at the current ambient temperature or the current cooling medium / cooling fluid temperature, wherein when the obtained pressure (p_inak) is greater than or equal to the static pressure (pR) that occurs at the ambient temperature, the extraction of the refrigerant from the non-working branch (14, 16) is activated (S504).

8. The method (500) according to claim 1 or 2, wherein, When the refrigeration equipment starts up or restarts, the refrigerant is extracted from the non-working branches (14, 16) (S504) to maximize the amount of refrigerant in the working branches (14, 16).

9. A refrigeration device (10) with heat pump function for motor vehicles, wherein, Refrigeration equipment (10) includes: A refrigerant compressor (12) is connected to or can be connected to the primary branch (14) and the secondary branch (16); An external heat exchanger (18) that acts directly or indirectly is arranged in the primary branch (14); Evaporator (22), the evaporator is arranged in the primary branch (14); At least one additional heat exchanger serving as a heat source is arranged in the secondary branch (16); A primary branch valve (A4) is arranged between the refrigerant compressor (12) and the external heat exchanger (18); A secondary branch valve (A3) is arranged between the refrigerant compressor (12) and the other heat exchanger that serves as a heat source; At least one valve device (A2, A5) is arranged between the high-pressure side section (15, 15a) of the primary branch (14) or the secondary branch (16) and the low-pressure side section located upstream of the refrigerant compressor (12); At least one pressure sensor (pT6, pT7) or pressure / temperature sensor is arranged in the high-pressure side section (15, 15a) of the primary branch (14) or the secondary branch (16) and configured to detect the pressure (p_inak) in the non-operating branch (14, 16) in an operating state where the primary branch (14) is operating and the secondary branch (16) is not operating, or in an operating state where the secondary branch (16) is operating and the primary branch (14) is not operating. The refrigeration equipment is designed to activate the suction of the refrigerant from the non-working branch to the working branch by reducing the pressure (pA) in the working branch to a value lower than the pressure (p_inak) in the non-working branch and by opening the valve devices (A2, A5).

10. The refrigeration equipment (10) according to claim 9, wherein, The other heat exchanger is a heating regulator (26).

11. A motor vehicle having a refrigeration device (10) according to claim 9 or 10.

12. The motor vehicle according to claim 11, wherein, The motor vehicle is a motor vehicle that is at least partially electrically powered.

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