DE102021131788A1 - Refrigerant cycle and cooling system for vehicles - Google Patents

Abstract

A refrigerant circuit for accumulator-electric vehicles, comprising a first sub-circuit comprising a compressor, a second sub-circuit connected to the first sub-circuit via a gas/liquid phase separator, the gas/liquid phase separator having a first oil return device, a second oil return device or a third oil return device connected to the compressor.

Description

The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 770019 ("The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 770019”).

field of invention

The field of the invention relates to the cooling of accumulators in general and in particular to a refrigerant circuit and a cooling system for accumulator-electric-powered vehicles.

State of the art

Despite the growing demand for (ultra) fast charging processes for electric vehicles, the state of the art in thermal management of accumulators or batteries is moving away from direct cooling towards indirect cooling. From a thermodynamic point of view, this trend is astonishing since direct cooling provides a much higher cooling capacity than indirect cooling for a given compressor or condensors.

With direct refrigerant cooling, the heat is collected directly by the refrigerant in the accumulator's heat exchanger, while with indirect accumulator cooling, the heat of the accumulator is collected in a coolant, which is counter-cooled by a coolant circuit via a cooler. In order to achieve the same cell temperature of an accumulator, the evaporation temperature in the accumulator heat exchanger with direct cooling is higher than in the cooler with indirect cooling. Therefore, the associated (saturated) pressure and vapor density at the compressor inlet are higher with direct cooling. This means that the compressor delivers more refrigerant mass flow at a given speed and thus provides a higher cooling capacity with direct cooling. Depending on the required operating temperature and the conductivity of the heat exchanger, direct cooling can provide about twice the cooling capacity compared to indirect cooling.

In terms of cost-efficiency, direct cooling potentially performs better than indirect cooling because it does not require a back cooler, coolant pump, coolant hoses, or valves.

The main problem with the direct cooling of accumulators arises when the refrigerant expands into a two-phase flow (gaseous and liquid) and is fed into several parallel sub-loops in order to cool the accumulator pack comprising a multiplicity of accumulator cells. Since the two-phase flow is dominated by the gas, the liquid is not evenly distributed over all sub-circuits. That is, cooling corresponding to the evaporation of the liquid is insufficient in some sub-circuits, while part of the liquid refrigerant flows uselessly through other sub-circuits without being vaporized.

The German patent application DE 10 2018 101 514 A1 teaches, for example, a motor vehicle refrigeration system with several evaporators of different refrigeration capacity and the associated integration of shut-off valves in order to close unused evaporators or to install a very powerful pump. The motor vehicle refrigeration system has a refrigerant circuit with at least one refrigerant compressor, at least one heat exchanger, at least one expansion device and at least two evaporators of different refrigeration capacity arranged parallel to one another. The at least two evaporators arranged parallel to one another are arranged downstream of the expansion device and upstream of the evaporator with a lower cooling capacity, with a gas/liquid phase separator for separating the liquid refrigerant. A refrigerant pump is arranged between the gas/liquid phase separator and the evaporator to convey the liquid refrigerant to the evaporator with lower cooling capacity, the gaseous refrigerant being able to be guided from the evaporator via the gas/liquid phase separator as a separator and sucked in by the refrigerant compressor.

The refrigerant circuit for direct cooling according to the prior art thus consists of two partial circuits that communicate via a gas/liquid phase separator. In the first sub-cycle, the refrigerant flows back into the gas/liquid phase separator from the gas outlet opening of the gas/liquid phase separator to a compressor, a heat exchanger and an expansion device. In the second part circuit, the refrigerant flows from the liquid outlet opening of a gas/liquid phase separator to a refrigerant pump and at least one evaporator back into the gas/liquid phase separator via an inlet which is separate from the inlet of the first part circuit.

The tribology management of the compressor is not discussed here. Despite the oil separation and oil return inside the compressor, some of the oil leaves the compressor so outlet and finally flows into the gas / liquid phase separator. Since this separator only returns gaseous refrigerant to the compressor, the oil is concentrated in the liquid refrigerant and circulates in the second sub-circuit. Eventually the compressor will run out of oil and run dry.

Furthermore, no possibility is described of reversing the refrigerant circuit in such a way as to provide accumulator cooling or vehicle cabin cooling in summer and heating via the heat pump in winter if required and/or desired.

The prior art also proposes using the refrigerant circuit with a plurality of evaporators that have different heat outputs. This requires the integration of isolation valves to close off unused evaporators or the installation of a very powerful pump to pump the liquid refrigerant stream through any unused or partially used evaporators.

The state of the art is limited in the application of direct cooling of accumulators to plug-in hybrid electric vehicles (PHEV) with rather small accumulator packs and only a few parallel sub-circuits.

With a few exceptions, direct refrigerant cooling is not used in purely electric vehicles with large battery packs. Otherwise, as described, indirect cooling is used by using a refrigerant circuit and a cooling circuit, which are coupled to one another via heat exchangers.

One aim of the present disclosure is to provide direct cooling with a self-lubricating refrigerant circuit for battery packs of different sizes in a vehicle.

Brief description of the invention

The present document describes a refrigerant circuit for accumulator-electrically powered vehicles, the refrigerant circuit comprising a first sub-circuit, comprising a compressor, and a second sub-circuit. The second sub-circuit is connected to the first sub-circuit via a gas/liquid phase separator, the gas/liquid phase separator being connected to the compressor via a first oil return device, a second oil return device or a third oil return device.

According to one aspect, the first sub-circuit comprises an A-line and the second sub-circuit comprises a B-line. The A line and the B line are components which are customary in the technical field of the invention and at least in sections at least one of a tube or a tube bundle made of parallel tubes or channels with partially different diameter(s), .

The refrigerant circuit according to the aforementioned aspect thus comprises two sub-circuits which are different from one another and which can take on different tasks within the refrigerant circuit.

In one aspect, the first oil return device and the second oil return device is an integral component of the gas/liquid phase separator.

The refrigerant circuit according to the aforementioned aspect can be made compact and can thus be used in a smaller installation space.

In one aspect, the third oil return device comprises a separate component connecting the first sub-circuit before the compressor and the second sub-circuit before the gas/liquid phase separator.

The refrigerant circuit according to the aforementioned aspect can be designed with smaller and simply designed components in order to be used in a complex installation space situation.

In one aspect, the gas/liquid phase separator includes a reservoir that holds a refrigerant, the refrigerant including gaseous refrigerant and liquid refrigerant.

The amount of refrigerant can be observed through the reservoir, for example by means of eyesight via a glass insert or a sensor, and refilled if necessary, which means that the refrigerant circuit can be operated more safely and for longer.

In one aspect, the liquid refrigerant is a mixture of liquid refrigerant and oil or pure refrigerant.

The liquid refrigerant, as well as the refrigerant, can not only cool but also lubricate.

In one aspect, the A-line is connected to the reservoir for receiving the gaseous refrigerant via a suction pipe and the B-line is connected via a suction line to the receiver of the liquid refrigerant connected to the reservoir.

The first sub-circuit is thus supplied with gaseous refrigerant via the suction pipe and the second sub-circuit is supplied with the liquid refrigerant via the suction line.

In one aspect, the suction tube includes a first hole for receiving a portion of the liquid refrigerant from the reservoir.

Part of the liquid refrigerant can be fed through the first hole into the first sub-circuit for lubricating the compressor.

In one aspect, the suction tube includes an opening for directly receiving a portion of the liquid refrigerant from the second sub-loop.

Part of the liquid refrigerant can be fed through the opening into the first partial circuit for lubricating the compressor.

In one aspect, the gas/liquid phase separator further includes a first component and a second component, wherein the first component delivers at least a portion of the liquid refrigerant from the second sub-loop directly to the second component.

As a result, part of the liquid refrigerant from the second partial circuit can be delivered directly to the second component without it staying in the reservoir.

In one aspect, the second component includes a collection device for receiving the released portion of the liquid refrigerant of the first component. In particular, the second component is designed as a tube, a funnel or a bowl.

As a result, part of the liquid refrigerant from the second partial circuit can be very well absorbed by the second component without it staying in the reservoir.

In one aspect, the second component is an integral component of the intake manifold.

The part of the liquid refrigerant is thus fed via the suction pipe into the first partial circuit for lubricating the compressor.

In one aspect, the first component includes at least one of a tube having at least one opening, a tube having a perforated wall, a baffle, and a coil.

Due to the special shape, part of the liquid refrigerant can be released from the first component to the second component in a targeted manner.

According to one aspect, the separate component comprises at least one hole for connecting the first partial circuit and the second partial circuit.

A part of the liquid refrigerant can be fed from the second sub-circuit into the first sub-circuit for lubricating the compressor through the at least one hole.

In one aspect, the discrete component includes a curved portion that imposes centrifugal forces on refrigerant flowing through the discrete component.

The liquid refrigerant is separated from the gaseous refrigerant of the refrigerant in the curved section by the centrifugal forces.

In one aspect, the bent portion includes at least one hole for at least a portion of the liquid refrigerant to flow through from the second sub-circuit into the first sub-circuit. The at least one hole is at least one of a component hole and a replacement plate hole.

A part of the liquid refrigerant can be fed from the second sub-circuit into the first sub-circuit for lubricating the compressor through the at least one hole.

In one aspect, the at least one replacement plate hole is integrated into a replaceable replacement plate.

The replacement plate can be easily replaced for cleaning or maintenance. The replacement plate can be replaced by a second replacement plate with at least one replacement plate hole in order to adapt the cross-sectional area of the at least one replacement plate hole to the conditions of the refrigerant circuit.

According to one aspect, the refrigerant circuit further includes a heat exchanger, an expansion valve, and a refrigerant pump. The heat exchanger and the expansion valve are arranged in the first partial circuit. The refrigerant pump is provided in the second sub-circuit.

character list

• 1 ist eine schematische Darstellung eines Kältemittelkreislaufs nach einem ersten Aspekt mit einem Gas-/Flüssigphasenabscheider nach einem ersten Aspekt.
• 2 ist eine schematische Darstellung des Kältemittelkreislaufs nach 1 mit einem Gas-/Flüssigphasenabscheider nach einem zweiten Aspekt.
• 3 ist eine schematische Darstellung eines Kältemittelkreislaufs nach einem zweiten Aspekt.
• 4 ist eine perspektivische Schnittdarstellung einer Teilkomponente des Kältemittelkreislaufs gemäß 3.
• 5 stellt ein illustratives Beispiel für den Einsatz des Kältemittelkreislaufs nach 1 dar.
• 6 zeigt eine schematische Darstellung des Kältemittelkreislaufs mit einem Verdampfungssystem gemäß einem Aspekt.

A more complete understanding of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description in conjunction with the accompanying figures.

• 1 Fig. 12 is a schematic representation of a refrigeration circuit according to a first aspect including a gas-liquid phase separator according to a first aspect.
• 2 Fig. 12 is a schematic diagram of the refrigerant circuit 1 with a gas/liquid phase separator according to a second aspect.
• 3 12 is a schematic diagram of a refrigerant circuit according to a second aspect.
• 4 FIG. 14 is a sectional perspective view of a partial component of the refrigeration cycle according to FIG 3 .
• 5 represents an illustrative example of the use of the refrigerant cycle 1 represent.
• 6 FIG. 12 shows a schematic representation of the refrigerant circuit with an evaporation system according to one aspect.

Detailed description of the invention

The invention will now be described with reference to the figures. It should be understood that the aspects of the invention described herein are exemplary only and do not in any way limit the scope of the claims. The invention is defined by the claims and their equivalents. It is understood that features of one aspect of the invention may be combined with a feature of another aspect or aspects of the invention, provided they are not mutually exclusive.

1 shows a schematic representation of a first aspect of a refrigerant circuit or refrigerant circuit 100 for cooling accumulators or batteries of vehicles. Use in electric rail and water vehicles is also possible. Accumulators or accumulator packs include a large number of accumulator cells, which develop high temperatures during operation due to the release of energy, for example due to the acceleration of electric motors, or the absorption of energy, for example charging. The refrigerant circuit 100 comprises a first sub-circuit A and a second sub-circuit B. The first sub-circuit A and the second sub-circuit B are connected to one another via a gas/liquid phase separator 120 . Usually, a large number of accumulators or accumulator packs are thermally connected as an evaporator system 128 in such a way that thermal energy or heat can be released from the accumulator cells to a refrigerant, as described in more detail later.

The first partial circuit A comprises a compressor or compressor 102, a heat exchanger 104 and an expansion device 106, all of which are connected to one another and to the gas/liquid phase separator 120 via an A line 101. The A line 101 is a component that is customary in the technical field of the invention and at least in sections includes at least one of a tube or a tube bundle made of parallel tubes or channels with partially different diameter(s). Therefore, for the sake of brevity, the A-line 101 will not be described in further detail.

The second partial circuit B comprises a refrigerant pump 126 and at least one evaporator system 128, with the refrigerant pump 126 and evaporator system 128 being connected to one another and to the gas/liquid phase separator 120 via a B line 125. The B-line 125 is a component that is customary in the technical field of the invention and at least in sections includes at least one of a tube or a tube bundle made of parallel tubes or channels with partially different diameter(s). Therefore, for the sake of brevity, the B-line 125 will not be described in further detail.

The gas/liquid phase separator 120 comprises a reservoir 121, a suction pipe 122 and a suction line 124. The suction pipe 122 comprises an opening 123. The reservoir 121 contains a refrigerant 115. The refrigerant 115 consists of a mixture of a refrigerant and oil or of pure refrigerant. The refrigerant consists, for example, of HFO-1234yf or R744 and the oil consists, for example, of a lubricating oil tailored to the respective compressor 102.

The refrigerant 115 is conducted via the suction line 124 by the refrigerant pump 126 to the evaporator system 128 in the second sub-circuit B. In the evaporator system 128, the refrigerant 115 evaporates and forms a gas/liquid mixture.

Due to the phase transition of the refrigerant 115 (liquid to vapor), there is an enhanced heat transfer process from high to low temperature. As a result of the evaporation of the refrigerant 115 in the evaporator system 128, thermal energy or heat from the environment or, for example, from the evaporator system 128 is released to the refrigerant circuit 100 and thereby cooled. In other words, the evaporation of the refrigerant 115 in the evaporator system 128 extracts energy in the form of heat from a medium that is in contact with the evaporator system 128 and is absorbed by the refrigerant 115 primarily through the phase transition from the liquid phase to the vapor phase (evaporation enthalpy).

In the second partial circuit B after the evaporator system 128, the refrigerant 115 thus consists of a mixture of a gaseous phase and a liquid phase. The gas/liquid mixture is fed to the gas/liquid phase separator 120 and separated into its gaseous and liquid phases with the aid of the gas/liquid phase separator 120 . The reservoir 121 is thus provided with the refrigerant 115 as a gaseous refrigerant 115g and as a liquid refrigerant 115f. Like the refrigerant 115, the liquid refrigerant 115f consists of a mixture of a liquid refrigerant and oil or of pure refrigerant.

The reservoir 121 is set up to hold the liquid refrigerant 115f and the gaseous refrigerant 115g. Since the liquid refrigerant 115f collects in the lower area of the reservoir 121 and the gaseous refrigerant 115g in the upper area of the reservoir 121, the suction pipe 122 for the gaseous refrigerant 115g is designed in such a way that the opening 123 of the suction pipe 122 always extends over a surface of the liquid Refrigerant 115f protrudes so as not to receive the liquid refrigerant 115f from the reservoir 121 through the opening 123. The suction line 124 for the liquid refrigerant 115f is configured to be provided at the bottom of the reservoir 121 and covered by the liquid refrigerant 115f.

The terms "upper area", "lower area" and "bottom of the reservoir" used here are to be understood as directional indications and describe positions which relate to a horizontal view of the reservoir 121, in which the liquid phase is closer due to the laws of physics at the surface of the earth as the gaseous phase of refrigerant 115.

The liquid refrigerant 115f is pumped to the evaporator system 128 in the second sub-circuit B via the suction line 124 by the refrigerant pump 126 . In the evaporator system 128, the liquid refrigerant 115f is converted into a mixture of a gaseous phase and a liquid phase, and in the gas/liquid phase separator 120, the two phases are separated from one another. So that the evaporator system 128, comprising for example a large number of accumulator packs, as described below, cools the large number of accumulator packs with a temperature distribution which is as homogeneous as possible, more liquid refrigerant 115f can be pumped into the evaporator system 128 than can evaporate therein. It can thereby be ensured that liquid refrigerant 115f evaporates over the entire run length, and thus no pure gas content is produced and overheated by further heat absorption. As a result, the evaporator system 128 in sub-circuit B is oversupplied or flooded, and this is referred to as flooded evaporation.

The separation of liquid refrigerant 115f and vaporous refrigerant 115g in the gas/liquid phase separator 120 prevents vaporous refrigerant 115g from flowing into the evaporator system 128 . In comparison to conventional refrigerant circuits, in which the refrigerant expands directly in front of the evaporator system 128, the evaporator system 128 is supplied with gaseous refrigerant 115g with a weight proportion of approximately 20% to 50% of the entire refrigerant mass flow. If the evaporator system 128 is supplied with gaseous refrigerant 115g with a weight proportion of approximately 20% to 50% of the total refrigerant mass flow, the volume proportion of the gaseous refrigerant 115g increases to up to 4000% relative to the liquid refrigerant 115f. With such high volume fractions of the gaseous refrigerant 115g, the flow velocity and the pressure loss would increase significantly in comparison to the purely liquid refrigerant 115f and negatively affect the process. In addition, in a case in which it would no longer be ensured that sufficient liquid refrigerant 115f was distributed uniformly in the evaporator system 128, inhomogeneous cooling and inhomogeneous temperature distribution would result.

Since the refrigerant flows through the evaporator system 128 at least partially as a two-phase flow or gas/liquid mixture, the pressure loss is directly associated with a temperature decrease, i.e. in conventional applications with refrigerants the temperature difference between the outlet and inlet in the evaporator system 128 is, for example, over an entire accumulator pack higher than flooded evaporation. In other words, the flooded evaporation provides a higher temperature homogeneity and thus a more homogeneous cooling, for example of battery packs, which reduces the aging of the battery cells of the battery packs can be minimized due to high temperature differences in the accumulator cells and between the accumulator cells.

Furthermore, the B-line 125 within the evaporator system 128 can be dimensioned longer due to the higher temperature homogeneity in its line length and thus provide a larger additional cooling surface for a larger number of accumulator cells. The flooded evaporation described here is therefore particularly useful for large battery packs in a rectangular installation space, such as those installed in many modern electric vehicles.

While the liquid refrigerant 115f is pumped into the second sub-circuit B via the suction line 124, the gaseous refrigerant 115g is simultaneously drawn from the reservoir 121 into the first sub-circuit A by the compressor 102 via the opening 123 of the suction pipe 122. The compressor 102 compresses the gaseous refrigerant 115g, as a result of which the volume of the gaseous refrigerant 115g decreases and the thermal energy or temperature of the gaseous refrigerant 115g increases. In order to dissipate the thermal energy of the gaseous refrigerant 115g, the gaseous refrigerant 115g is guided through the heat exchanger 104 following the compressor 102 and is cooled. By the time it exits the heat exchanger 104, the refrigerant 115 is at least partially converted from the gaseous phase into the liquid phase. The refrigerant 115 is preferably converted completely into the liquid phase, so that it is present as a liquid refrigerant 115f. The cooled refrigerant 115 is then expanded or brought to a lower pressure by the expansion device 106, as a result of which the refrigerant 115 is in turn converted into two phases, a liquid phase and a gaseous phase. The gas/liquid mixture is fed to the reservoir 121 of the gas/liquid phase separator 120 .

The suction tube 122 includes at least one suction hole 129 provided near the bottom of the reservoir 121 . Part of the liquid refrigerant 115f enters the suction pipe 122 through the suction hole 129 and mixes with the gaseous refrigerant 115g. The liquid refrigerant 115f is led to the compressor 102 together with the gaseous refrigerant 115g. The liquid refrigerant 115f, comprising oil, lubricates and/or cools the compressor 102. This ensures that the compressor 102 does not run dry and the cycle in the first sub-cycle A can be operated over a very long period of time. The suction hole 129 in the suction pipe 122 and the A line 101 define a first oil return device 120A, which returns the oil contained in the refrigerant 115 or in the liquid refrigerant 115f to the compressor 102 and thereby ensures that the compressor 102 is lubricated.

2 FIG. 12 is a schematic diagram of the refrigerant circuit 100 of FIG 1 with a gas/liquid phase separator 120 according to a second aspect. The gas-liquid phase separator 120 according to the second aspect has the same structure as the gas-liquid phase separator 120 in FIG 1 , however, the gas/liquid phase separator 120 according to the second aspect further comprises a first component 1201 and a second component 1203 and the suction tube 122 does not comprise a suction hole 129. The first component 1201 is arranged to extend the second sub-circuit B into the reservoir 121 . The first component 1201 is designed to deliver at least part of the liquid refrigerant 115f from the second partial circuit B directly to the second component 1203. In other words, the first component 1201 directs at least part of the liquid refrigerant 115f from the second sub-circuit B to the second component 1203. The first component 1201 comprises at least one of a tube with at least one opening, a tube with a perforated wall, a baffle plate and a spiral. The first component 1201 can be a single component assembled with the gas/liquid phase separator 120 or an integral component with the gas/liquid phase separator 120 .

The second component 1203 includes a collection device for receiving the discharged portion of the liquid refrigerant 115f of the first component 1201. The second component 1203 directs the discharged portion of the liquid refrigerant 115f directly to the opening 123 of the suction tube 122. The collection device of the second component 1203 comprises at least one of a tube, a funnel, or a bowl. The second component 1203 may be a single component assembled with the intake manifold 122 or an integral component with the intake manifold 122 . Due to the design of the second component 1203, the first component 1201 feeds at least part of the liquid refrigerant 115f directly into the opening 123 (see FIG 1 ) of the intake manifold 122. The second component 1203 thus receives at least part of the liquid refrigerant 115f directly from the second sub-circuit B. This ensures that the compressor 102 is supplied with at least part of the liquid refrigerant 115f from the second sub-circuit B and does not run dry. The cycle in the first sub-cycle A can thus be operated over a very long period of time.

The first component 1201, the second component 1203 and the A-line 101 define a second oil return device 120B, which returns the oil contained in the refrigerant 115 or in the liquid refrigerant 115f to the compressor 102 and thereby ensures the lubrication of the compressor 102.

An advantage of the first oil return device 120A and the second oil return device 120B is that the concentration of the oil dissolved in the refrigerant after the partial evaporation in the evaporator system 128 can be higher than in the liquid refrigerant 115f, which is in the reservoir of the gas/liquid phase separator 120 . This allows a smaller mass flow of liquid refrigerant 115f to be returned to the compressor 102 with the same amount of dissolved oil, thereby increasing efficiency. Due to the lower mass flow of the liquid refrigerant 115f, the efficiency of the compressor 102 and thus of the entire refrigerant circuit 100 increases.

3 shows a schematic representation of the refrigerant circuit 100 for cooling accumulators or batteries of vehicles according to a second aspect. The same components of the refrigerant circuit 100 according to the second aspect are provided with the same reference symbols of the refrigerant circuit 100 according to the first aspect and not repeated for the sake of brevity described in detail.

The gas/liquid phase separator 120 resembles the gas/liquid phase separator 120 in this case 1 , but with the difference that the suction pipe 122 is set up without a suction hole 129.

The refrigerant circuit 100 further includes a separate component 140, including a sub-component 240 (see 4 ), connecting the first sub-circuit A and the second sub-circuit B. The separate component 140, 240 is arranged in the first sub-circuit A between the gas/liquid phase separator 120 and the compressor 102. The separate component 140, 240 is arranged in the second partial circuit B between the evaporator system 128 and the gas/liquid phase separator 120. The separate component 140, 240 includes a first space A* and a second space B*. The first space A* is connected to the A line 101 of the first partial circuit A via an A inlet 141 and an A outlet 142 . The second space B* is connected to the B line 125 of the second partial circuit B via a B inlet 143 and a B outlet 144 .

The first space A* and the second space B* of the separate component 140, 240 may have different shapes and are connected to each other by a component hole 212. As a result, at least part of the liquid refrigerant 115f from the second partial circuit B passes through the component hole 212 of the separate component 140, 240 into the first space A*. In the first space A*, the liquid refrigerant 115f mixes with the gaseous refrigerant 115g sucked into the A line 101 by the suction pipe 122 and flows on to the compressor 102. This ensures that the compressor 102 is filled with at least part of the liquid refrigerant 115f is supplied from the second partial circuit B and does not run dry. The cycle in the first sub-cycle A can thus be operated over a very long period of time.

The B line 125, the separate component 140, 240 with the second hole 212 and the A line 101 define a third oil return device 212AB, which returns the oil contained in the refrigerant 115 or in the liquid refrigerant 115f to the compressor 102 and thereby provides lubrication of the compressor 102 is ensured.

An advantage of the third oil return device 212AB is that the concentration of oil in the refrigerant 115 can be higher. The third oil return device 212AB can be designed to return a lower mass flow of refrigerant to the compressor 102, which can increase the efficiency of the system.

Another advantage of the third oil return device 212AB is that the gas-liquid phase separator 120 can be made smaller and the return can be integrated separately. This flexibility increases the ability to be integrated, particularly in confined spaces.

4 12 illustrates a perspective sectional view of the sub-component 240 included in the separate component 140 of the refrigerant circuit according to FIG 3 The second space B* located between the B inlet 143 and the B outlet 144 has, for example, a curved or round section 210 . The curved section 210 causes centrifugal forces on the gas/liquid mixture of the refrigerant flowing through the second region B* of the partial component 240 . Due to the centrifugal forces, at least part of the liquid refrigerant 115f is branched off from the gas/liquid mixture of the refrigerant and passes through the component hole 212 into the first space A* and further through at least one exchange plate hole 214 into the first sub-circuit A. The exchange plate hole 214 is in an exchangeable replacement plate or a washer 216 integrated. The replacement plate 216 can be replaced by the sub-component 240 when the replacement plate hole 214 becomes dirty or the subcomponent 240 is removed for maintenance or replacement.

5 12 represents an illustrative example for the use of the refrigerant circuit 100. A bus 501 with an electric drive comprises the refrigerant circuit 100 on the roof. 5 12 thus represents an illustrative example of the evaporator system 128 of the refrigerant circuit 100, which does not limit the scope of the invention.

The bus 501 includes the refrigerant circuit 100 and a plurality, for example six, battery packs 510 on the roof. The heat exchanger 104 of the refrigerant circuit 100 is provided on the bus 501 in such a way that the thermal energy or heat present there is released to the ambient air.

6 FIG. 12 shows a schematic representation of the refrigerant circuit 100 with the evaporation system 128 according to FIG 5 . The refrigerant 115 in the B line 125 of the second partial circuit B flows through each of the plurality of accumulator packs 510 . In this case, the coolant 115 is routed to each of the plurality of accumulator packs 510 via its own line inlet 521 of the B line 125 . The refrigerant returns to the B-line 125 via a separate line outlet 531 on each of the large number of accumulator packs 510.

The bus 501, comprising the refrigerant circuit 100, is charged overnight and is in operation all day without the accumulator packs 510 being fully recharged. The respective battery pack 510 is charged with 250 kilowatts (kW) in about six minutes during the day after about an hour of operation during a driver's break. Due to the short charging time with 250 kW, the respective battery packs 510 become very hot. This thermal energy is absorbed by the liquid refrigerant 115f in the B line 125, resulting in a phase transition from the liquid phase to the gaseous phase. Due to the evaporation of the liquid refrigerant 115f in the evaporator system 128 due to the very hot accumulator packs 510, thermal energy or heat is released from the accumulator packs 510 to the refrigerant circuit 100 and thereby cooled.

In a modified example, the refrigerant circuit 100 may be configured such that at least a part of the B line 125 is routed through a vehicle cabin of the bus 501 in order to cool the vehicle cabin in summer and in winter if necessary and/or desired to heat the vehicle cabin.

In another modified example, the refrigerant circuit 100 may be configured such that the cycle is reversed to cool the vehicle cabin in the summer and heat the vehicle cabin in the winter as needed and/or desired.

Fast charging with efficient accumulator cooling by flooded evaporation reduces weight, required volume and investment and increases the overall service life of the 501 bus.

Reference List

100

Refrigerant circulation

101

A line

102

compressor

104

heat exchanger

106

expansion device

115

refrigerant

115f

liquid refrigerant

115g

gaseous refrigerant

120

gas/liquid phase separator

121

reservoir

122

intake manifold

123

opening (of the intake manifold)

124

suction line

125

B line

126

refrigerant pump

128

vaporizer system

129

first hole

140

separate component

141

A inlet

142

A outlet

143

B inlet

144

B outlet

210

curved section 212 second hole

214

third hole

216

replacement plate

240

subcomponent

1201

first component

1203

second component

A

first sub-cycle

B

second sub-cycle

A*

first room

B*

second room

120A

first oil return device

120B

second oil return device

212AB

third oil return device

501

bus

510

battery pack

521

line input

531

line output

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102018101514 A1 [0007]

Claims (18)

Refrigerant circuit (100) for accumulator-electric vehicles, the refrigerant circuit (100) comprising: a first sub-circuit (A) comprising a compressor (102), a second sub-circuit (B) connected to the first sub-circuit (A) via a gas/liquid phase separator (120), wherein the gas/liquid phase separator (120) is connected to the compressor (102) via a first oil return device (120A), a second oil return device (120B) and/or a third oil return device (212AB). Refrigerant circuit (100) after claim 1 , In which the first partial circuit (A) comprises an A-line (101) and the second partial circuit (B) comprises a B-line (125). Refrigerant circuit (100) according to one of Claims 1 and 2 wherein the first oil return device (120A) and the second oil return device (120B) are an integral component of the gas/liquid phase separator (120). Refrigerant circuit (100) according to one of Claims 1 until 3 , wherein the third oil return device (212AB) is a separate component (140) comprising a sub-component (240), the first sub-circuit (A) before the compressor (102) and the second sub-circuit (B) before the gas/liquid phase separator (120) connecting, encompassing. Refrigerant circuit (100) according to one of Claims 1 until 4 wherein the gas/liquid phase separator (120) comprises a reservoir (121) and the reservoir (121) receives a refrigerant (115), the refrigerant (115) comprising a gaseous refrigerant (115g) and a liquid refrigerant (115f). . Refrigerant circuit (100) after claim 5 , in which the liquid refrigerant (115t) consists of a mixture of a liquid refrigerant and oil or pure refrigerant. Refrigerant circuit (100) according to one of Claims 5 or 6 , if in each case directly or indirectly dependent on claim 2 , in which the A line (101) is connected to the reservoir (121) by means of a suction pipe (122) for receiving the gaseous refrigerant (115g) and the B line (125) is connected to the reservoir (121) by means of a suction line (124) connected to receive the liquid refrigerant (115f). Refrigerant circuit (100) after claim 7 wherein the suction tube (122) includes a first hole (129) for receiving a portion of the liquid refrigerant (115f) from the reservoir (121). Refrigerant circuit (100) according to one of Claims 7 or 8th , wherein the suction pipe (122) comprises an opening (123) for directly receiving part of the liquid refrigerant (115f) from the second sub-circuit (B). Refrigeration circuit (100) according to any one of the preceding claims, in which the gas/liquid phase separator (120) further comprises a first component (1201) and a second component (1203), the first component (1201) containing at least part of the liquid refrigerant ( 115t) from the second partial circuit (B) directly to the second component (1203). Refrigerant circuit (100) after claim 10 , in which the second component (1203) comprises a collection device for receiving the released part of the liquid refrigerant (115t) of the first component (1201), in particular the second component (1203) is designed as a tube, a funnel or a bowl. Refrigerant circuit (100) according to one of Claims 10 or 11 wherein the second component (1203) is an integral component of the intake manifold (122). Refrigerant circuit (100) according to one of Claims 10 , 11 or 12 wherein the first component (1201) comprises at least one of a tube having at least one opening, a tube having a perforated wall, a baffle and a coil. Refrigerant circuit (100) after claim 4 or one of the Claims 5 until 13 , if directly or indirectly dependent on claim 4 , wherein the partial component (240) comprises at least one hole (212; 214) for connecting the first partial circuit (A) and the second partial circuit (B). Refrigerant circuit (100) after claim 4 or one of the Claims 5 until 14 , if directly or indirectly dependent on claim 4 wherein the sub-component (240) comprises a curved section (210) causing centrifugal forces on the refrigerant (115) flowing through the sub-component (240). Refrigerant circuit (100) after claim 15 , wherein the bent portion (210) comprises at least one hole (212; 214) for at least part of the liquid refrigerant (1 15f) to flow through from the second sub-circuit (B) into the first sub-circuit (A). Refrigeration circuit (100) according to any of the preceding claims, wherein a third hole (214) is integrated in a replaceable replacement plate (216). Refrigeration circuit (100) according to any one of the preceding claims, further comprising a heat exchanger (104) and an expansion valve (106) arranged in the first sub-circuit (A), and a refrigerant pump (126) provided in the second sub-circuit (B).

Images