DE102018105609A1 - Method for cooling in a vehicle - Google Patents

Abstract

Method for cooling in a vehicle, comprising the steps of: vaporizing refrigerant in a first evaporator, which is preferably associated with at least one first refrigeration consumer, vaporizing refrigerant in a second evaporator, which is preferably associated with at least one second refrigeration consumer Supplying the refrigerant from the first evaporator to at least a first input of a compressor at a first pressure level and supplying the refrigerant from the second evaporator to at least one second input of the compressor at a second pressure level, which is higher than the first pressure level.

Description

The invention relates to a method for cooling in a vehicle, a cooling system in a vehicle, a compressor for a vehicle, a use of a compressor and a vehicle, in particular electric vehicle.

In vehicles, especially electric vehicles, the cooling of various areas and / or components is partly desirable and sometimes technically necessary. For example, batteries in battery-powered electric vehicles or even hybrid vehicles, including fuel cell hybrid vehicles, usually have to be cooled. If a battery temperature exceeds a certain value (for example, at least about 40 ° C), the life of a battery may be compromised. It is therefore known that in such batteries heat must be dissipated by (active) cooling from the battery. Especially at high outside temperatures and / or at high loads (by loading and unloading), it is necessary to cool the battery (active). This becomes particularly significant at high battery capacities, which can be in the range of at least about 100 kWh. For an often desired speeding then services of at least about 300 kW can be included. This comparatively high power losses and thus heating of the battery are connected. But even with comparatively low power and capacity can (active) cooling with a medium below or close to (or at or possibly at least slightly above, eg in situations in which the vehicle and / or the battery eg by sunlight is still heated, cooling but still requires active cooling) of the ambient temperature may be required to keep the battery at a favorable temperature level and dissipate waste heat generated by losses in charging.

So far, batteries in finished vehicles, for example, cooled directly (by evaporation of refrigerant within the battery) or indirectly (via a so-called chiller and a low-temperature secondary circuit) via a refrigerant circuit of a vehicle air conditioning. However, with comparatively high cooling capacities required both for the air conditioning of the passenger cabin and for the cooling of the battery, the refrigerant compressors currently used are often insufficient. Therefore, more powerful compressors are being considered. These must then be made larger and heavier. Another alternative is the use of additional compressors. However, this is considered to be relatively expensive.

It is an object of the invention to propose a method for cooling in a vehicle, which can be carried out in a simple manner and efficiently, and in particular with a comparatively low load on installation space. Furthermore, it is an object of the invention to propose a corresponding cooling system, a compressor and a corresponding vehicle, in particular electric vehicle.

• - Verdampfen von Kältemittel in einem ersten Verdampfer, der vorzugsweise mindestens einem ersten Kälte-Verbraucherzugeordnet ist,
• - Verdampfen von Kältemittel in einem zweiten Verdampfer, der vorzugsweise mindestens einem zweiten Kälte-Verbraucherzugeordnet ist,
• - Zuführen des Kältemittels aus dem ersten Verdampfer zu mindestens einem ersten Eingang eines Verdichters auf einem ersten Druckniveau und
• - Zuführen des Kältemittels aus dem zweiten Verdampfer zu mindestens einem zweiten Eingang des Verdichters auf einem zweiten, vorzugsweise gegenüber dem ersten Druckniveau erhöhten, Druckniveau.

In particular, the object is achieved by a method for cooling in a vehicle, preferably an electric vehicle, comprising the steps:

• Vaporizing refrigerant in a first evaporator, which is preferably associated with at least one first refrigeration consumer,
• Vaporizing refrigerant in a second evaporator, which is preferably associated with at least one second refrigeration consumer,
• - Supplying the refrigerant from the first evaporator to at least a first input of a compressor at a first pressure level and
• - Supplying the refrigerant from the second evaporator to at least a second input of the compressor at a second, preferably increased with respect to the first pressure level, pressure level.

A central idea of the invention is to use a (common) compressor which, in addition to the refrigerant (suction gas) from the first evaporator (which is preferably assigned to at least one refrigeration consumer, in particular an air conditioning system), also refrigerant (suction gas) from a second Evaporator (which is preferably at least a second refrigeration consumer, in particular a battery, assigned) to absorb (suck). Preferably, in this case, the refrigerant sucked in by the compressor (suction gas) from the second evaporator is at a middle pressure level (intermediate pressure level) between a pressure level (evaporation pressure) of the refrigerant sucked in by the compressor from the first evaporator (low pressure) and a condensation pressure or high pressure (or high pressure). pressure side of the compressor).

Advantageously, therefore, a cold (and / or heat) generation via two evaporators in (only) a circuit with (only) a compressor done, which is energetically advantageous. Furthermore, this size and weight can be saved. Overall, a comparatively high performance can be achieved with a compact structure and comparatively high efficiency.

Basically, a liquid or gas injection (at medium pressure) from stationary cooling systems is known. In this case, so-called economizer circuits are used, which should improve the efficiency of the cooling and be used to reduce a compression end temperature. Such economizer circuit is, for example, in DE 10 2007 010 646 A1 described.

The second pressure level (p ₂ ) is preferably at least 10%, preferably at least 25%, more preferably at least 40% and / or at most 90%, preferably at most 80%, of a difference between condensation pressure (p _out ) (at the outlet of the compressor) and first pressure level (p ₁ ) greater than the first pressure level (p ₁ ); ie: p ₂ ≥ p ₁ + 0.1 * (p _from -p ₁ ), preferably p ₂ ≥ p ₁ + 0.25 * (p _from -p ₁ ), more preferably p ₂ ≥ p ₁ +0.4 * (p _from -p ₁ ) and / or p ₂ ≤ p ₁ + 0.9 * (p _from -p ₁ ), preferably p ₂ ≤ p ₁ + 0.8 * (p _from -p ₁ ). The first evaporator is preferably associated with at least one first refrigeration consumer.

Alternatively or additionally, heat from a compressor connected downstream of the compressor for heating a vehicle area (in particular a vehicle interior) and / or a vehicle component can be used. In particular, in this case, it may be advantageous if individual or all heat exchangers (evaporators, condensers) act indirectly and cool a brine or heat a heat carrier (it may preferably be the coolant used in the vehicle anyway).

However, it is particularly preferred to use cold from the first evaporator in a vehicle air conditioning system (in particular for cooling a passenger compartment or a vehicle interior).

The cold from the second evaporator is preferably used to cool a battery. Alternatively or additionally, the cold from the second evaporator can also be used to cool down electronics (in particular power electronics). Advantageously, therefore, a cooling for air conditioning and cooling of a battery in (only) a circuit with (only) a compressor (at different temperature levels) take place, which is energetically advantageous. Furthermore, this size and weight can be saved. Overall, a comparatively high performance can be achieved with a compact structure and comparatively high efficiency.

The compressor (compressor) can be formed in one or more stages. Preferably, the compressor is or comprises a scroll compressor and / or a screw compressor and / or a, in particular multi-stage, rotary piston compressor. In particular scroll compressors are advantageous as compressors for vehicles with electrified powertrain.

It can be provided exactly a second input. Alternatively, a plurality of second inputs may be provided, which may be arranged so that a respective pressure level in the compressor (compressor) differs in the region of the respective second input. During the procedure, multiple second inputs may be used, or only one (as needed) one of several second inputs. A corresponding selection can for example be made via (switching) valves and / or slides and / or other adjusting devices. Alternatively or additionally, at least one second input can be displaced (or be designed to be displaceable), in particular in such a way that, depending on the positioning of the displaceable second input, a corresponding pressure level (in the respective input area) can be adapted or selected. In particular, the at least one second displaceable input is thus displaceable so that it can be displaced from a suction side of the compressor in the direction of a pressure side (or vice versa). If a plurality of second inputs are provided, these too are preferably arranged so that at least one of the plurality of second inputs is closer to a suction side than another of the plurality of second inputs. Overall, therefore, it can be cooled variably and effectively.

It is possible that in a further variant, at least one third evaporator is provided on one (in particular for this optimum pressure and thus temperature level). Thereby, e.g. Air conditioning of the interior, cooling of the battery and cooling of the power electronics space and efficiency optimized on particular different temperature levels.

The at least one first and / or at least one second input may be present as a bore.

An (especially automatic) valve (pressure valve) can be provided at an outlet of the compressor, in particular so as to adapt the compression process of the charge (for the at least one second input) and an optionally energetically disadvantageous over-compression of the refrigerant (eg of the gas). to avoid.

Refrigerant flows (suction volume flows) from the first evaporator and the second evaporator and, if appropriate, further evaporators can also be brought together (if required) prior to entry into the compressor or can be brought together. The merging can be done for example via a valve that allows either a merge depending on the position or prevented. In the case of a corresponding operating mode, the advantage of the two different pressure levels may then be lost, but this may be advantageous, for example, for operation of only one of the evaporators. A corresponding valve can in particular be integrated in the compressor (compressor), that is to say be arranged in particular in a compressor housing.

• - einen ersten Verdampfer zum Verdampfen von Kältemittel sowie mindestens einen dem ersten Verdampfer zugeordneten ersten Kälte-Verbraucher,
• - mindestens einen zweiten Verdampfer zum Verdampfen von Kältemittel sowie mindestens einen dem zweiten Verdampfer zugeordneten zweiten Kälte-Verbraucher,
• - einen Verdichter mit mindestens einem ersten und mindestens einem zweiten Eingang derart, dass Kältemittel aus dem ersten Verdampfer durch den mindestens einen ersten Eingang auf einem ersten Druckniveau aufnehmbar ist und Kältemittel aus dem zweiten Verdampfer durch den mindestens einen zweiten Eingang auf einem zweiten, gegenüber dem ersten Druckniveau erhöhten, Druckniveau aufnehmbar ist.

The above object is further achieved in particular by a cooling system in a vehicle, in particular for carrying out the above method, comprising

• a first evaporator for evaporating refrigerant and at least one first refrigeration consumer associated with the first evaporator,
• at least one second evaporator for evaporating refrigerant and at least one second refrigerating consumer assigned to the second evaporator,
• a compressor having at least one first and at least one second input such that refrigerant from the first evaporator is receivable through the at least one first input at a first pressure level and refrigerant from the second evaporator through the at least one second input at a second, opposite to first pressure level increased, pressure level is recordable.

Preferably, a vehicle air conditioning, in particular as the first refrigeration consumer, is provided. Furthermore, a battery and / or power electronics, in particular as a (respective) second cold consumer can be provided. The compressor can be configured in one or more stages. Furthermore, the compressor can form or include a scroll compressor and / or a screw compressor and / or a, in particular multi-stage, rotary piston compressor.

There may be several second inputs. Alternatively or additionally, at least one second input may be displaceable.

At an output of the compressor, a, in particular automatic, pressure valve may be provided.

Refrigerant streams from the first evaporator and the second evaporator may be merge (as required) prior to entry into the compressor, in particular via a valve, preferably integrated in the compressor.

The above object is further achieved by a compressor for a vehicle, in particular a motor vehicle, preferably an electric vehicle, in particular for carrying out the above method and / or for the cooling system described above and / or as part of the cooling system described above, comprising at least a first and at least a second input such that refrigerant from a first evaporator is receivable by the at least one first input at a first pressure level, and refrigerant from a second or even further evaporator through the at least one second input at a second or even third (particularly opposite to the first Pressure level increased) pressure level is absorbable. The compressor is preferably formed in one or more stages. Furthermore, the compressor may be a scroll compressor or a screw compressor or a, in particular multi-stage, rotary piston compressor or comprise a scroll compressor and / or a screw compressor and / or a, in particular multi-stage, rotary piston compressor. Other, in particular multi-stage compressor designs are possible.

The compressor is preferably configured for use in a vehicle, in particular a motor vehicle, preferably an electric vehicle or hybrid vehicle, ie designed to meet requirements arising within the mobile application, in particular vibrations and / or accelerations and / or weight restrictions and / or or space restrictions. In particular, (but not exclusively) the compressor is configured for use in a passenger car and / or truck and / or a bus and / or an agricultural machine.

The above object is further achieved, in particular, by the use of a compressor of the above type in a vehicle (preferably a motor vehicle, in particular an electric vehicle), in particular for cooling in a vehicle air conditioning system and / or for cooling a battery and / or power electronics. The above object is further achieved by a vehicle, in particular an electric vehicle, comprising a cooling system of the above type and / or a compressor of the above type.

Optionally, in the vehicle (s), two or more than two evaporators may be operable (or operated) on respective different (compared to at least one other evaporator or optionally different or all other evaporators) evaporator pressure levels.

In the (in) the vehicle may optionally at least partially a heating operation (in particular in a switchable mode of operation) be possible (or carried out).

The compressor is preferably comparatively compact, thus occupies a volume of preferably less than 5000 cm ³ , more preferably less than 1000 cm ³ and even more preferably less than 500 cm ³ . A weight of the compressor may preferably be at most 10 kg, more preferably at most 5 kg. The (entire) compressor can be housed in a (single) compressor housing. A diameter of the compressor (wherein the diameter here means in particular a maximum distance of a pair of points, taking into account all pairs of dots forming the compressor) may preferably be a maximum of 20 cm, more preferably a maximum of 12 cm.

Between the compressor and the first and second evaporator and optionally further evaporators (with their respective expansion organs), a single and optionally also multi-part condenser and / or liquid collector (condensate collector) may be connected downstream. For example, two capacitors (condenser) can be operated simultaneously or reversibly alternately, on the one hand to dissipate heat to the environment and on the other hand to recover heat for heating.

First and second evaporator and possibly further evaporators are connected in parallel according to the embodiment.

In each case one or more (for example two) valves (eg shut-off and / or expansion valve) can be connected in front of the first and / or second evaporator, which can optionally be controlled accordingly to supply a refrigerant flow through the first or second evaporator allow or block or control (regulate). In particular, (preferably electronically controlled or controllable) expansion valves (in front of the respective evaporator) may be provided.

The refrigerant may preferably be R134a, R1234yf, R290 or R744 (CO ₂ ). The use of other refrigerants is also possible.

Overall, according to the invention, an efficient, low installation space-demanding and yet powerful cooling, in particular of a battery, can be achieved in a vehicle. Specifically, it has been recognized that cooling a battery to maintain it at or below a certain temperature of, for example, (at least about) 40 ° C and cooling a passenger compartment at vaporization temperatures in the range of, for example, between 0 ° C and 10 ° C is energetically disadvantageous with a single simple refrigerant circuit.

In principle, a refrigerant cooling temperature provided via the first evaporator may be above a temperature provided by the second evaporator (or vice versa), for example at least 5 ° C. or at least 10 ° C. higher.

Further embodiments emerge from the subclaims.

The invention will also be described in terms of further features and advantages with reference to an embodiment, which is explained in more detail with reference to the drawings.

• 1 eine schematische Darstellung eines erfindungsgemäßen Verdichters;
• 2 eine schematische Darstellung eines erfindungsgemäßen Kühlsystems.

Hereby show:

• 1 a schematic representation of a compressor according to the invention;
• 2 a schematic representation of a cooling system according to the invention.

In the following description, the same reference numerals are used for identical and equivalent parts.

1 is a first embodiment of a compressor according to the invention.

In this compressor 10 It is a scroll compressor that can suck gas from the evaporator of an air conditioner. In this case, outer, sickle-shaped compression chambers, the scroll compressor can fill with the gas. In the further compression process, these spaces are closed, shrinking and compressing the gas on its way to an exit 11 (Outlet opening), which are arranged here inside the (fixed) scroll spiral.

At a suitable point, the (orbiting) spiral of the compressor will now be (are) 10 run over a (multiple) bore (s) that release the suction gas from a battery associated with the second evaporator (medium-pressure evaporator). The compressor size is characterized in an advantageous manner by the intake volume flow from a first evaporator 13 determined (see also 2 ). The compressor 10 This makes it compact.

Due to the inflow of the (medium pressure) gas, the pressure in the corresponding chambers is increased (jump-like) during the compression. So there is a kind of "charging effect". The total delivered refrigerant mass increases by the proportion that flows in at this pressure (medium pressure). It can thereby cooling capacity for both evaporators 12 . 13 to be provided.

The refrigerant (suction gas) from the first evaporator can via a first input 14 be supplied. The gas (refrigerant) from the second evaporator 12 can have a second input 15 to the compressor 10 be supplied.

Preferably, there are several second inputs 15 (not shown in the figures). Alternatively or additionally, at least one displaceable second input 15 (Medium pressure bore) are present, which can be positioned according to valves, slides and / or other adjustment.

As in 2 recognizable, are first and second evaporator 12 . 13 connected in parallel. Between this parallel circuit and the compressor are (downstream of the compressor 10 ) a capacitor 16 and a condensate collector 17 , The first or second evaporator 12 . 13 are each at least one or more valves 18a . 18b ( 19a . 19b ), for example, exactly two valves 18a . 19a or. 18b . 19b , upstream. These valves are arranged in particular after a branching in the two branches of the above-mentioned parallel circuit. Furthermore, these valves can be (in particular electronically controlled or controlled) expansion valves. A corresponding control can via control devices 20a . 20b respectively. On the outlet side to the first and second evaporator 12 . 13 subsequent lines 21a . 21b can have a valve 22 (optional).

At the valve 18a and or 19a it is in particular an expansion valve. At the valve 18b and or 19b it is in particular a shut-off valve.

The 2 shows concretely a schematic diagram of the interconnection of refrigerants in the subcritical range, such as R134a, R1234yf and R290. In particular, the circuit options shown in dashed lines are not mandatory.

A circuit for transcritical refrigerant processes, such as with R744 (CO ₂ ), can be deduced accordingly.

LIST OF REFERENCE NUMBERS

10

compressor

11

exit

12

second evaporator

13

first evaporator

14

first entrance

15

second entrance

16

capacitor

17

condensate collector

18a

(Expansion) valve

18b

(Turn-off) valve

19a

(Expansion) valve

19b

(Turn-off) valve

20a

control device

20b

control device

21a

management

21b

management

22

Valve

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102007010646 A1 [0008]

Claims (17)

Method for cooling in a vehicle, comprising the steps: Vaporizing refrigerant in a first evaporator (13), which is preferably associated with at least one first refrigeration consumer, Vaporizing refrigerant in a second evaporator (12), which is preferably associated with at least one second refrigeration consumer, - Supplying the refrigerant from the first evaporator (13) to at least a first input (14) of a compressor (10) at a first pressure level and - Supplying the refrigerant from the second evaporator (12) to at least a second input (15) of the compressor at a second, compared to the first pressure level increased, pressure level. Method according to Claim 1 , characterized in that cold from the first evaporator (13) is used in a vehicle air conditioner and / or cold from the second evaporator (12) is used to cool a battery and / or power electronics. Method according to Claim 1 or 2 , characterized in that the compressor (10) comprises a scroll compressor or a screw compressor or a, in particular multi-stage, rotary compressor or other multi-stage compressor. Method according to one of the preceding claims, characterized in that a plurality of second inputs (15) are provided and / or the at least one second input (15) is displaced or displaceable. Method according to one of the preceding claims, characterized in that an, in particular automatic, pressure valve is provided at an output of the compressor (10). Method according to one of the preceding claims, characterized in that the refrigerant streams from the first evaporator (13) and the second evaporator (12) are merged or merge before entering the compressor (10). Cooling system in a vehicle, in particular for carrying out the method according to one of the preceding claims, comprising a first evaporator (13) for evaporating refrigerant and at least one first refrigeration consumer associated with the first evaporator (13), a second evaporator (12) for evaporating refrigerant and at least one second refrigerating consumer assigned to the second evaporator (12), - A compressor (10) having at least a first (14) and at least one second (15) input such that refrigerant from the first evaporator (13) through the at least one first input (14) is receivable at a first pressure level and refrigerant the second evaporator (12) is receivable by the at least one second input (15) at a second, in particular with respect to the first pressure level increased, pressure level. Cooling system after Claim 7 , characterized by a vehicle air conditioning system, in particular as a first cold consumer, and / or a battery and / or power electronics, in particular as a second cold consumer. Cooling system after Claim 7 or 8th , characterized in that the compressor (10) is formed in one or more stages and / or the compressor (10) comprises a scroll compressor or a screw compressor or a, in particular multi-stage, rotary compressor or other multi-stage compressor. Cooling system according to one of the Claims 7 to 9 , characterized in that a plurality of second inputs (15) are present and / or the at least one second input (15) is displaceable. Cooling system according to one of the Claims 7 to 10 , characterized in that at an output of the compressor a, in particular automatic, pressure valve is provided and / or the refrigerant streams from the first evaporator (13) and the second evaporator (12) are merge before entering the compressor, in particular a, preferably in the compressor (10) integrated, valve (22). Compressor (10) for a vehicle, in particular a motor vehicle, preferably an electromobile, in particular for carrying out the method according to one of the preceding claims Claims 1 to 6 and / or for a cooling system and / or as part of a cooling system according to one of Claims 7 to 10 comprising at least a first (14) and at least one second (15) input such that refrigerant from a first evaporator (13) is receivable through the at least one first input (14) at a first pressure level and refrigerant from a second evaporator (12 ) is receivable by the at least one second input (15) at a second, compared to the first pressure level increased, pressure level. Compressor (10) after Claim 12 , characterized in that the compressor (10) is formed in one stage or more stages and / or comprises a scroll compressor or a screw compressor or a, in particular multi-stage, rotary compressor or other multi-stage compressor. Use of a compressor (10) after Claim 12 or 13 for cooling in a vehicle, in particular for cooling in a vehicle air conditioning system and / or for cooling a battery and / or power electronics. Vehicle, in particular electromobile, comprising a cooling system according to one of Claims 7 to 11 and / or a compressor (10) according to one of Claims 12 or 13 , Vehicle after Claim 15 in which two or more than two evaporators are operable at two and more than two evaporator pressure levels, respectively Vehicle after Claim 15 or 16 in which in a switchable mode of operation at least partially a heating operation is possible.

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