EP2304202A1

EP2304202A1 - Device for cooling a coolant, circuit for charging an internal combustion engine, and method for cooling a substantially gaseous charging fluid for charging an internal combustion engine

Info

Publication number: EP2304202A1
Application number: EP09776661A
Authority: EP
Inventors: Marcus Weinbrenner; Andreas Kemle; Ottokar Kunberger; Bernd Schäfer
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2008-06-16
Filing date: 2009-05-29
Publication date: 2011-04-06
Also published as: US20110146266A1; WO2010003484A1; DE102008028290B4; DE102008028290A1; JP5627575B2; JP2011524483A

Abstract

The invention relates to a device (1, 2) for cooling a coolant, for cooling a charging fluid (L) for charging an internal combustion engine, having a refrigerant guide (20), particularly a refrigerant circuit, and a coolant guide (10), particularly a coolant circuit; wherein – the refrigerant guide (20) comprises a first evaporator (29) for a refrigerant for cooling an ambient air and a second evaporator (19) for a refrigerant for cooling the coolant, - the coolant guide (10) comprises a heat exchanger (11) for the charging fluid (L), a coolant cooler (13), and the second evaporator (19) for the refrigerant of the refrigerant guide (20) for cooling the coolant. According to the invention, in a first variant, the first and the second evaporator (29, 19) are disposed in series in the refrigerant guide (20). In a second variant, the first evaporator (29) and the second evaporator (19) are disposed in parallel in the refrigerant guide (20), particularly wherein a suction throttle (35) is disposed downstream in the refrigerant flow after the second evaporator (19). A refrigerant bypass (30, 31, 33) for the first and/or second evaporator (29, 19) preferably serves for controlling the performance of the first and/or second evaporator (29, 19).

Description

BEHR GmbH & Co. KG Mauserstrasse 3, 70469 Stuttgart

Device for cooling a coolant, circuit for charging an internal combustion engine and method for cooling an intended for charging an internal combustion engine substantially gaseous charging fluid

The invention relates to a device for cooling a coolant, which is provided for cooling a charging fluid for charging an internal combustion engine, with a refrigerant guide and a coolant guide; wherein the refrigerant guide has a first evaporator for a refrigerant for cooling an ambient air and a second evaporator for a refrigerant for cooling the refrigerant; the coolant guide has a heat exchanger for the charging fluid, a coolant cooler and the second evaporator for a refrigerant of the refrigerant guide for cooling the coolant. The invention further relates to a circuit for charging an internal combustion engine, comprising a compressor in a flow guidance of a charging fluid provided for the charging fluid and a heat exchanger for the charging fluid. The invention further relates to a method for cooling an intended for charging an internal combustion engine substantially gaseous charging fluid.

A charging of internal combustion engines with cooled charging fluid, in particular a substantially gaseous charging fluid, for example a charge air and / or an exhaust gas or mixtures comprising a charge air and / or an exhaust gas, is used in vehicles, inter alia, due to legal provisions to the particle and Reduce pollutant emissions, in particular nitrogen oxide emissions. As the requirements for exhaust gas pollution control become stricter, larger exhaust gas mass flows are required, which charging systems should be mastered. In addition, a specific liter of power can be increased in the event that one is able to design previously used charging systems with a smaller space requirement - so-called "downsizing." By "downsizing" fuel can be saved as well as by an additional cooling of a charging fluid. As a result, the charging fluid is provided to the combustion process with a comparatively cool temperature, which is associated with a density increase in the charging fluid and thus allows better cylinder filling at reduced combustion temperatures. As a result, the charging fluid in the internal combustion engine can be compressed higher, resulting in the above-described consumption reduction or performance increase. Otherwise, the cooling of the charging fluid is insufficient due to interference, a comparatively worse cylinder filling and thus a faster reaching the limit temperatures and a consequent lower compression in the internal combustion engine. The result is a sensitive reaction of the fuel consumption with less power of the internal combustion engine.

Thus, on the one hand in the field of diesel engines for commercial vehicles as well as gasoline engines is known to provide basically two-stage charging fluid cooling to improve a cooling performance when cooling a charging fluid. For commercial vehicles, such systems are described, for example, in WO2005 / 111392 A1 or in EP 0 496 085 A1. Further two-stage cooling systems suitable for motor vehicles are described in EP 1 432 907 B1, EP 1 445 454 A1 and EP 0 678 661 B1. In this case, two heat exchangers-a so-called high-temperature heat exchanger and a so-called low-temperature heat exchanger-flow through charging fluid, which can be used as needed for cooling the charging fluid, and accordingly with one or more bypass channels for a charging fluid are provided. Thus, for example, Heat exchanger for charge air cooling, as in DE 10 2004 045 661 A1 arrange in a charge air duct.

In addition to the above-known measures of a two-stage cooling of the charging fluid as such, a particularly effective cooling of the charging fluids as described in DE 1 9859129 A1 possible. In this case, the compressed by a compressor charging fluid for cooling with cooling liquid of the charge air cooler is brought into interaction and brought the cooling liquid of the charge air cooler in turn for cooling with a coolant / refrigerant evaporator of the air conditioning in interaction. Such a system has proven to be even better, since this works with only a single evaporator of the air conditioning. Accordingly, the applicant, for example in DE 1 0210132 A1 or DE 1 0254016 A1, a device of the type mentioned above with a first evaporator in the form of a refrigerant / refrigerant evaporator and a second evaporator in the form of a climatic evaporator has been proposed. In the refrigerant guide, the refrigerant is expanded in a climatic evaporator for cooling an ambient air and compressed in a compressor. The first evaporator in the form of the refrigerant / refrigerant evaporator and the second evaporator in the form of the air-conditioning evaporator are connected in parallel in the refrigerant guide. In principle, it has been shown that even such systems react comparatively sensitively.

It would be desirable to have a further improved concept for providing improved cooling performance for a charge fluid using first and second evaporators for a refrigerant.

At this point, the invention begins, the object of which is a device for cooling a coolant, which is provided for cooling a charging fluid for charging an internal combustion engine, and to provide a circuit for charging an internal combustion engine. Another object is to provide a method for cooling an intended for charging an internal combustion engine substantially gaseous charging fluid. The devices and method should be able to more effectively provide charge fluid cooling performance. In particular, an effective utilization of the cooling capacity of the first and second evaporator should be achieved even with different operating conditions of an internal combustion engine. - A -

The object relating to the device is achieved by a device of the type mentioned, is provided in accordance with the invention that - in a first variant - the first and the second evaporator in the refrigerant guide are arranged in a row or - in a second variant - the first Evaporator and the second evaporator are arranged in the coolant guide in parallel arrangement, wherein the refrigerant downstream of the second evaporator, a suction throttle is arranged.

The object with regard to the circuit is achieved by a circuit of the type mentioned at the beginning, in which according to the invention a device coupled via the heat exchanger for the charging fluid according to the concept of the invention is provided.

A refrigerant guide is preferably provided in the form of a refrigerant circuit. A coolant guide is preferably provided in the form of a coolant circuit.

The invention is based on the consideration that it is basically possible to intervene in the architecture of a refrigeration cycle and / or by an appropriate regulation of the refrigeration cycle, even with different power requirements, both the cooling of ambient air and the cooling of the coolant in an improved manner to ensure. Investigations have shown that a first and second evaporator work on a significantly different temperature level, even if only slightly, at least in individual cases. For example, a first evaporator for a refrigerant for cooling an ambient air will work regularly at air temperatures between 20 ⁰ C and 70 ⁰ C - but possibly only during the first few minutes of a preferred cooling of a passenger compartment by the air conditioner. In contrast, a Kühlmitteleintrittstempe- is temperature for a second evaporator for a refrigerant for cooling the refrigerant usually between 25 ° C and 80 ⁰ C. Thus, a long-term average temperature level of the second evaporator is more likely to be above that of a first evaporator, resulting in the need for a customized architecture and / or control strategy for handling the device. The invention has recognized that - in a first variant - a series arrangement of the first and second evaporator, in contrast to a mere parallel arrangement of a first and second evaporator without additional measures as in the aforementioned prior art of the Applicant, to an improved architecture and Regulation possibility of the refrigeration cycle leads. Namely, it has been found that by the said series arrangement for the first and the second evaporator an approximately same Saugdruckumgebung results, which can be handled advantageously by means of suitable actuators to operate as needed, the first and / or the second evaporator , Together, this has the advantage of minimizing the problem of refrigerant transfer and oil circulation.

The invention has further recognized that - in a second variant - to arrange a parallel arrangement of the first evaporator and the second evaporator in the refrigerant guide, in particular together with the additional measure, downstream of the refrigerant downstream of the second evaporator, a suction choke, superior to the prior art. In particular, it is possible for the second evaporator to be at approximately the same suction pressure as the first evaporator because of the additional pressure drop caused by the suction throttle. As recognized by the invention, a long-term average temperature level of the second evaporator is more likely to be above that of a first evaporator. As a result, a suction pressure at the second evaporator tends to be higher than that of the first evaporator. In principle, any organ which, for example, by a cross-sectional reduction in the coolant downstream part of the refrigerant duct downstream of the second evaporator leads to an additional pressure drop, is suitable as a suction throttle causing a pressure drop. This solution becomes possible because the refrigerant side pressure drop of the second evaporator, in particular CAS evaporator, can be optimized without unduly affecting the performance of the refrigeration system. Basically, this organ can also be an expansion organ / valve, such as an EXV or TXV. The use of a suction throttle advantageously also allows the use of a TXV or the like. Expansion organ additionally or alternatively. Basically proves a suction throttle as cheaper compared to a switching valve. However, a combination of suction throttle and shut-off valve proves to be vorteil._Dadurch that by means of the suction throttle a parallel-connected second evaporator and first evaporator at a comparatively equal suction level, results in a particularly advantageous simultaneous operating mode of the second evaporator and the first evaporator. The concept of the invention leads in both evaporators to comparatively equal evaporation pressures and evaporation temperatures. In particular, the concept also has the advantage that, for example, the suction throttle can be adjusted so that there is a tendency to superheated refrigerant in order to avoid, for example, liquid portions in the vaporized refrigerant.

The above-described concept of the invention has proved to be particularly advantageous for a coolant circuit, which is formed in the form of a low-temperature circuit. In this case, a heat exchanger in the form of an indirect intercooler and / or a coolant radiator in the form of a low-temperature radiator is particularly preferably formed. A coolant circuit preferably has a coolant pump and further suitable measures for guiding the coolant in the coolant guide, in particular in the coolant circuit.

It has also proven to be particularly preferred in the context of the concept of the invention that a refrigerant circuit is designed for an air conditioning system, in particular moreover comprises a refrigerant compressor, a condenser, or gas cooler or the like, suitably a collector and / or dryer is downstream.

As a particularly preferred in the context of the concept of the invention, a first evaporator for a refrigerant in the form of an HVAC evaporator has been found. As a further particularly preferred in the context of the concept of the invention, a second evaporator for refrigerants has proven in the form of a CAS evaporator. An internal combustion engine is preferably formed as a motor or internal combustion engine, preferably a gasoline engine. Also possible is the realization as a diesel engine.

Further, advantageous developments of the invention can be found in the dependent claims and indicate in detail advantageous possibilities to realize the above-described concept within the scope of the task, as well as with regard to further advantages.

It has proved to be particularly advantageous in the context of the first variant that the second evaporator is arranged downstream of the first evaporator. In principle, it is also possible-in the context of the first variant-alternatively also that the first evaporator is arranged downstream of the second evaporator. Advantageously, the first evaporator is a CAS evaporator. Advantageously, the second evaporator is a HVAC evaporator.

In the context of a particularly preferred development of the invention, it is provided for the power control of the first and / or second evaporator that the refrigerant guide in each case has a refrigerant bypass for the first and / or second evaporator. In particular, it can be provided that an actuating member for actuating the respective refrigerant bypass is arranged upstream of the respective first and / or second evaporator. In particular, a suitable actuating member may be a three-way reversing valve and / or an arrangement of two shut-off valves and / or a respective shut-off valve with an expansion element. In the context of the second variant, it has proved to be particularly advantageous that a refrigerant bypass for the second evaporator before the intake throttle leads into the refrigerant guide. In the event that no pressure reduction is desired in the bypass mode, it may be advantageous for the refrigerant bypass for the second evaporator to lead into the refrigerant guide after the suction throttle. Overall, it is possible by the aforementioned developments of the invention alone or in combination in the context of the concept of the invention, the first and / or second evaporator with the above-mentioned advantages for the adjustment of the suction pressure at- regulate the evaporator depending on the needs and operating condition of the internal combustion engine or on or off.

In a particularly preferred embodiment of the invention, means for measuring the power of the first and / or second evaporator are also provided in the device. This can be done, for example, by using an air inlet temperature and an air quantity.

In addition, it has proved to be advantageous that an electric and / or thermostatic expansion element, in particular with a shut-off function, is arranged cold in the upper part of the first evaporator and / or the second evaporator. Such and other power control means of the first and / or second evaporator have been found to be particularly preferred. In principle, all power control means, e.g. under measurement of pressure and temperature of the refrigerant before and / or after the first and / or second evaporator.

In addition, it has proved to be advantageous for the coolant guide to have a sensor for determining the coolant temperature. This measure advantageously makes it possible to regulate an alternate actuation of the first and / or second evaporator in the event that a power requirement of the first and second evaporator lies above a power limit of the refrigerant guide.

A particularly preferred development of the invention provides a coolant bypass for the second evaporator in the coolant guide. This proves to be advantageous for the inventive concept according to the first variant and in particular the second variant. It has been found that an actuation of the coolant bypass for controlling the coolant temperature can serve to provide the cooling capacity of the coolant guide in addition to the charge air to a further system part available, for example an electronics. Such a situation may prove advantageous if the further system part, such as the electronics, has an increased cooling demand. In this respect, a charge air cooler in the form of a heat exchanger can be practically replaced by the coolant side coolant. Switch off the bypass. A cold mid-side compensation for regulating the coolant temperature can be achieved by means of the coolant guide. This also has the advantage that a coolant guide does not have to be designed for a maximum requirement, but rather the available cooling capacity of the refrigerant guide can be taken into account in the design. The coolant bypass can be used on the coolant side in this respect for an indirect power control on the second evaporator, in particular a CAS evaporator. Indirectly this allows a power control of the intercooler. The coolant temperature indirectly regulates the refrigerant-side power at the second evaporator, in particular charge-air (CAS) evaporator, since this influences the evaporator pressure and thus the refrigerant temperature. When the coolant temperature rises, the refrigerant pressure and therefore the refrigerant temperature increases, and thus the refrigerant side power on the CAS evaporator decreases.

In a particularly preferred embodiment of the concept of the invention, in a device of the above-mentioned type, the refrigerant bypass for the second evaporator is actuated in a first operating state characterized by a coolant temperature lying below a limit temperature. Alternatively, in such a device, neither the refrigerant bypass for the second evaporator nor the refrigerant bypass for the first evaporator is actuated in a second operating state characterized by a coolant temperature lying above a limit temperature. In the latter alternative, if a power requirement of the first and second evaporator is below a power limit of the refrigerant line, both evaporators can be used for cooling the coolant. In the second alternative, if a power demand of the first and second evaporators is above a power limit of the refrigerant guide, the refrigerant bypass for the second evaporator and the refrigerant bypass for the first evaporator may be alternately operated. As a proviso for determining the operating state, the temperature signal of a sensor can be used to determine the coolant temperature. Incidentally, the aforementioned means for power measurement and power control may be used as needed and circumstantially within the scope of the concept of the invention. To achieve the object with regard to the method for cooling an essentially gaseous charging fluid provided for charging an internal combustion engine, the invention provides a method according to the aforementioned type, in which according to the invention it is provided that

- Is operated in a first by a lying below a temperature limit temperature coolant operating condition of the cold ittelby- pass for the second evaporator is actuated. Alternatively, according to the invention, neither the refrigerant bypass for the second evaporator nor the first evaporator is actuated either in a second operating state characterized by a coolant temperature above a limit temperature. Or in the context of the second alternative, it has proven to be advantageous that, in particular in the event that a power requirement of the first and second evaporator is above a power limit of the refrigerant guide, the refrigerant bypass for the second evaporator and the first evaporator is operated alternately , Preferably, the method is carried out with a device and / or a circuit of the type described above.

It has proved to be particularly preferred that the limit temperature has a value between 40 ⁰ C and 55 ° C, in particular between 40 ⁰ C and 50 ⁰ C, takes.

Embodiments of the invention will now be described below with reference to the drawing. This is not necessarily to scale the embodiments, but the drawing, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing, reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The features of the invention disclosed in the description, in the drawing and in the claims can be used individually as well as in any desired grain size. be essential for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to an article which would be limited in comparison to the subject matter claimed in the claims. For the given design ranges, values within the specified limits should also be disclosed as limit values and should be usable and able to be used as desired. In detail, the drawing shows in:

1 shows a schematic view-according to the first variant-of a first embodiment of a circuit for charging an internal combustion engine not shown in detail with a preferred, coupled via a heat exchanger for the charging fluid device according to the concept of the invention.

2 shows a schematic view, according to the first variant, of a second embodiment of a circuit for charging an internal combustion engine (not shown in more detail) with one via one

Heat exchanger for the charge fluid coupled device according to the concept of the invention;

3 shows a schematic view of a modified embodiment according to the first variant;

4 shows a schematic view-according to the second variant-of a third embodiment of a circuit for charging an internal combustion engine (not shown) with a preferred device coupled to the charging fluid via a heat exchanger according to the concept of the invention;

5 shows a schematic view-according to the second variant-of a fourth embodiment of a circuit for charging a non-illustrated internal combustion engine with a preferred one device coupled via a heat exchanger for the charge fluid according to the concept of the invention;

6 shows a schematic view-according to the second variant-of a modified third embodiment of FIG. 4; FIG.

FIG. 7 shows a schematic view-according to the second variant-of a fourth embodiment modified to FIG. 5; FIG.

8 shows a schematic view of two modifications of a detail of the circuit of the first, second or third embodiment relating to the arrangement of a coolant cooler and condenser with respect to the flow of cooling air;

9 shows a logic diagram relating to the setting of different operating states in a device according to the concept of the invention and / or in the context of a method according to the concept of the invention for cooling a substantially gaseous charging fluid intended for charging an internal combustion engine;

10 is a schematic representation of different operating states of the device in the context of a particularly preferred embodiment of a method as a function of a limit temperature of the coolant.

A present symbolically illustrated circuit 100 for charging an internal combustion engine, in particular a motor - preferably on Benzinbasis - with a charging fluid L has according to the concept of the invention via a heat exchanger 11 for the charging fluid L coupled device 1, which for cooling a coolant is designed, which in turn is provided for cooling the charging fluid for charging the internal combustion engine. FIGS. 1 to 3 show embodiments according to the first variant, in which the first and second evaporators 29, 19 are arranged in rows. are switched. Fig. 2 and Fig. 3 show further modifications of such a circuit 100 with a correspondingly modified device 1, wherein the same reference numerals are used for simplicity for identical parts or features or parts or features the same function. As charging fluid L, in particular a substantially gaseous charging fluid - for example a charge air and / or an exhaust gas or mixture comprising a charge air and / or an exhaust gas - can be understood. The present examples and embodiments are not limited to a specific form of a charging fluid, but described using the example of a charging fluid L in the form of a charge air.

In the present case, the device 1 has a refrigerant guide 20 in the form of a refrigerant circuit and a coolant guide 10 in the form of a coolant circuit.

The coolant guide 10 is designed to guide the coolant and, in addition to the heat exchanger 11 that can be acted upon by the charge oil L and coolant to cool the charge air L, has a coolant cooler 13 downstream of the heat exchanger 11 downstream of the coolant, and a coolant pump 15 downstream of the coolant to recirculate the coolant. The coolant is further supplied via a three-way valve 17 designed as a changeover valve either a bypass 10 ^' for the direct return of the coolant to the heat exchanger 11, or if necessary, a further coolant line section 10 ^" to the coolant to a CAS referred to herein as the second evaporator 19 This is designed for further cooling of the coolant and can also be charged with refrigerant - in other words, the second evaporator 19 in the form of a CAS evaporator couples the coolant guide 10 and the refrigerant guide 20. About the further course of the cooling - Medium guide 10, the coolant is then further supplied to the aforementioned heat exchanger 11 for cooling the charging fluid L.

The refrigerant guide 20 is designed to guide a refrigerant and correspondingly has a refrigerant compressor 21, which firstly supplies the previously substantially gaseous refrigerant to a condenser 23 supplies, which can be designed as a gas cooler if required. The arrangement of condenser 23 and coolant radiator 13 is preferably co-flowed together by cooling air K in order to extract heat from the coolant and / or the refrigerant and thereby cool or condense. The arrangement of condenser 23 and coolant radiator 13 is shown in FIG varied in the views (A) and (B) and described in detail as different modifications.

The refrigerant is then fed via the refrigerant guide 20 in largely liquid form to a collecting dryer 25, which can also serve as a reservoir for the refrigerant. Subsequently, the refrigerant via a designed as a changeover valve first three-way valve 24 for on-demand actuation of a first bypass 31 either via an expansion element 26 - in the present case designed as a thermostatic expansion element TXV - referred to as a first evaporator 29 evaporator for the refrigerant in the form of an HVAC Supplied to the evaporator 29, or recycled to the first evaporator 29 in the bypass 31 to the original refrigerant guide 20. Thereafter, the refrigerant is further supplied via a switching valve designed as a second three-way valve 28 either via a further expansion organ 22 to the aforementioned first evaporator 19 in the form of a CAS evaporator, or if necessary past this by the second bypass 33rd back to the original refrigerant guide 20. The first evaporator 29 is provided for cooling an ambient air - in the present case as part of an air conditioning system for cooling a passenger compartment. In the course of the leadership of the refrigerant via the expansion elements 26, 22 and the evaporators 29, 19 taking place evaporation of the refrigerant leads to further guidance of the refrigerant in gaseous form through the refrigerant guide 20 in turn back to the refrigerant compressor 21, the same for liquefaction of the refrigerant itself the Capacitor 23 leads.

The expansion elements 26, 22 can be designed as needed and in particular be provided with a shut-off function, not shown, so that they are suitable for power control of the first evaporator 19 and the second evaporator 29. 2 shows a substantially identical embodiment of a circuit 100 with a device 1, as was explained with reference to FIG. 1, with the difference that the first expansion element 26 in the present case is designed as an electrical expansion element EXV, while the first expansion element 26 the device 1 in Fig. 1 is designed as a thermostatic expansion element TXV. In contrast to the device 1 in FIG. 1, the design of the expansion element 26 as EXV enables the measurement of pressure and temperature of the refrigerant before and after the first evaporator 29 and thus a power control of the first evaporator 29 designed for this purpose Advantage that a power at the evaporator 29 can be withdrawn in favor of the evaporator 19, which leads to an increase in performance at the evaporator 19. A corresponding measuring line 40 is coupled both in Fig. 1 and in Fig. 2 for a device 1 cold ittelstromabwärts after the evaporators 29, 19 to the refrigerant guide 20 and - in the case of the device 1 of FIG. 1 - at the first three-way valve 26 in Form of the TXV connected and - in the case of the device 1 of FIG. 2 - on the first expansion element in the form of the EXV and directly after the first evaporator 29 on the refrigerant guide 20 connected. The corresponding sections of the measuring line for pressure and temperature 40 are designated 40 'and 40 ".

FIG. 3 shows both embodiments of FIGS. 1 and 2 modified in a figure, the second embodiment of FIG. 2 having the first expansion element in the form of the EXV and the further section 40 "of the measuring line 40 being shown in corresponding dotted lines This is to make clear that the further modification of the device 1 shown in Fig. 3 can be implemented advantageously both for the embodiment of Fig. 1 and Fig. 2. The modification of the device 1 in Fig. 3 provides that the Heat exchanger 11 and the second evaporator 19 for the refrigerant for cooling the coolant in the form of a CAS evaporator can be advantageously realized in the context of a single unit, which is flowed through by the charging fluid L. A cycle 200 shown symbolically in FIG. 4 to FIG. 7 is likewise provided for charging an internal combustion engine, in particular an engine, preferably based on gasoline, with a charging fluid L, as already explained with reference to FIGS. 1 to 3. In turn, according to the concept of the invention, the latter has a device 2 coupled via a heat exchanger 11 for the charging fluid L and designed for cooling a coolant, which in turn is provided for cooling the charging fluid to charge the internal combustion engine. FIGS. 4 to 7 show embodiments according to the second variant, in which the first and second evaporators 29, 19 are connected in parallel. In the following, even if the embodiments of FIGS. 4 to 7 are devices 2 and circuits 200 which are designed differently from the devices 1 and circuits 100 of FIGS. 1 to 3-for the sake of simplicity identical reference numerals used for identical parts or features or parts or features the same function.

In the present case, in turn, a coolant guide 10 is designed for guiding the coolant and has, in addition to the loadable with charging fluid L and coolant heat exchanger 11 for cooling the charge air L a Kühlmittelstromabwärtig downstream coolant radiator 13 and further Kühlmittelstromabwärtig a coolant pump 15 for circulating the coolant. For further cooling of the coolant in the present embodiment of the device 2 is provided for a circuit 200, that always the complete coolant mass flow through the second evaporator 19, in the form of a designated again as a CAS evaporator coolant / refrigerant evaporator, is performed. Over the further course of the coolant guide 10, the coolant is then further supplied to the aforementioned heat exchanger 11 for cooling the charging fluid L.

In addition, in the coolant guide 10, as in the embodiment according to FIG. 6, a coolant bypass 10 'which can be switched via the three-way valve 17 is provided for the second evaporator 19 in the coolant guide 10. The coolant bypass 10 'can cool down telseitig so far for an indirect power control on the second evaporator 19, in particular a CAS evaporator, are used.

In the present case, the refrigerant guide 20 is again designed to guide a refrigerant and accordingly has a refrigerant compressor 21, which first supplies the previously substantially gaseous refrigerant to a condenser 23, which can also be designed as a gas cooler if required. The arrangement of the condenser 23 and the coolant cooler 13 is preferably co-flowed together by cooling air K in order to extract heat from the coolant and / or the refrigerant and thereby to cool it or to condense it. The arrangement of condenser 23 and coolant radiator 13 is modified in FIGS. 8 (A) and (B) and described in greater detail as different modifications.

The refrigerant is then fed via the refrigerant guide 20 in largely liquid form to a collecting dryer 25, which can also serve as a reservoir for the refrigerant. The refrigerant is then - depending on the state of the shut-off valves 28 'and 24' - as needed the second evaporator 19 in the form of the CAS evaporator and / or the first evaporator 29 in the form of the HVAC evaporator via a suitable expansion element 22 ', 26' fed. Both the second evaporator 19 and the first evaporator 29 can each be bridged via a bypass 30. In the case of the first evaporator 29, the bypass 31 departs from the expansion element 26 'and flows cold downstream from the first evaporator 29 back into the refrigerant duct 20. In the case of the second evaporator 19, the bypass 33 departs from the expansion element 22' and discharges at the downstream side of the refrigerant behind the second evaporator 19 in the refrigerant guide 20th

In a first embodiment according to the second variant of the invention, FIG. 4 shows a device 2 in which the refrigerant bypass 33 of the second (CAS) evaporator 19 downstream of the second evaporator 19 and upstream of a suction throttle 35 opens into the refrigerant guide 20. Fig. 5 shows a modified further second embodiment of a device 2, wherein in otherwise identical design of the refrigerant bypass 33 to the second evaporator 19 behind said Suction choke 35 - or, as explained above, another suitable organ such as an EXV. opens into the refrigerant guide 20.

FIG. 6 and FIG. 7 show further modified third and fourth embodiments according to the second variant of the invention, which - analogous to the third and fourth embodiment of the second variant of the invention - are implemented with the modification that - similar to the embodiment of the first variant of the invention in Fig. 3 explained - the heat exchanger 11 and the second evaporator 19 for the refrigerant for cooling the coolant in the form of a CAS evaporator are advantageously realized in the context of a single unit, which is flowed through by the charging fluid L.

In principle, however, it is also possible in FIGS. 6 and 7 to arrange the heat exchanger 11 separately from the second evaporator 19 in a section downstream of the coolant bypass 10 'to the coolant guide 10 and in front of the coolant cooler 13.

In the third embodiment according to FIG. 6, a refrigerant bypass 33 can-but does not necessarily have to-be provided. In particular, the refrigerant bypass 33 would be conducted downstream of the second evaporator 19 and upstream of the suction throttle 15 to the refrigerant guide 20. In Fig. 7 in the fourth embodiment of the second variant of the invention, the refrigerant bypass 33 is guided behind the suction throttle 35 to the refrigerant guide 20.

Due to the third and fourth embodiment according to the second variant of the invention, as shown in Fig. 4 to Fig. 7, it is again - this time also in a parallel arrangement of the second evaporator 19 and the first evaporator 29 - possible, both evaporators at comparatively same suction pressure level to operate. The suction pressure of the second evaporator 19 (CAS evaporator) is lowered in an advantageous manner by the suction throttle 35.

The additional operation of the second evaporator 19 is present angest- REBT particular for the case that the coolant temperature is more than 40 ⁰ C. up to 55 ° C. In this case, opens the shut-off valve 28 'for the second evaporator 19 and this is traversed by refrigerant. Due to the high coolant mass flow, the temperature difference of the coolant through the second evaporator 19 5 ⁰ C to 10 ⁰ C - the coolant outlet temperature is then present about 30 ⁰ C to 55 ° C, depending on the inlet temperature. Since the temperature levels of the two evaporators 19, 29 are greatly different insofar, the suction pressure levels of the first evaporator 29 and the second evaporator 19 are designed differently by the suction throttle 35 according to the concept of the invention in the second variant. In the present case, the suction throttle 35 is integrated into the manifold of the second evaporator 19, refrigerant downstream in the refrigerant guide 20. An expansion element 22 '- in the present example, in the form of a thermal expansion valve - controls the overheating of the suction throttle 35. Thus, for example, a standard TXV (thermal Expansion valve) can be used.

The refrigerant side pressure drop in the second evaporator 19 is not very critical in this case because it can be offset against the Saugdrosseldruckabfall. In a modified modification, the suction throttle 35 may also be designed as an electrically actuated expansion valve or timing valve. As a result, the suction throttle 35 can be combined with the shut-off valve 28 '. The latter leads to the saving of an additional valve.

Further, Fig. 8 shows in views (A) and (B) two possible modifications for arranging a condenser 23 and coolant radiator 13 relative to each other, which are suitable for both variants of the invention. In the variants of a coolant circuit with a coolant guide 10, which are explained above and can be realized particularly advantageously in the context of FIG. 8, the coolant circuit is advantageously realized as a low-temperature circuit. The heat exchanger 11 is advantageously realized as an indirect intercooler. Accordingly, the coolant radiator 13 is advantageously realized in the form of a low-temperature radiator. View (A) of FIG. 8 shows the arrangement of the coolant cooler 13 and the condenser 23 as shown in FIGS. 1 to 7 described so far. This arrangement has proved to be particularly advantageous for the formation of the refrigerant guide 20, because the cooling air K flows in this arrangement, first the capacitor 23 and thus preferably the refrigerant cools. In the arrangement of a condenser 23 and a coolant radiator 13 shown in view (B) of FIG. 8, the coolant radiator 13 is first supplied with cooling air, so that this arrangement proves to be particularly advantageous for heat dissipating relief of the coolant guide 10. This modification can also be used as required in a device 1 of FIGS. 1 to 7.

A coolant-side switching valve 17 has proven to be advantageous in the manner described above for actuating the coolant-side bypass 10 ', so as to bypass the second evaporator 19 and thus to regulate indirectly. A switching valve 28 or shut-off valve 29 'has proven to be particularly advantageous for switching off the second evaporator 19 in the form of the CAS evaporator. This causes a reduction of the coolant-side pressure drop and thereby a lower power consumption of the coolant pump 15, which ultimately leads to fuel savings. In addition, the second evaporator in the form of the CAS evaporator can also be replaced by a comparatively small refrigerant-side mass flow - e.g. in the context of a constructive forced leakage of the expansion device - "cold" held to provide in case of need quickly due to the low temperature level of the mass - ie the stored "cold" - a cooling capacity available. This will be explained in more detail with reference to the following FIGS. 9 and 10 for explaining an operating strategy of the previously explained embodiments of a device 1, 2 and a circuit 100, 200. Overall, by the advantageous use of the illustrated shut-off valves 24, 24 ', 28, 28' and / or expansion elements 26, 26 ', 22, 22' before both evaporators 29, 19 each of the evaporators 29, 19 are operated individually or alternatively, depending on the power requirement and response in the refrigeration cycle and which refrigerant displacement is given.

The previously explained embodiments of a device 1, 2 are not restrictive - on the contrary, further implementations of a device according to the concept of the invention as claimed are also suitable. For example, in an embodiment not shown here, the first variant the invention of the second evaporator designed as a CAS evaporator can also be arranged in series in front of the first evaporator designed as a HVAC evaporator. In a further modification, an arrangement of two shut-off valves for actuating the bypass sections 30 may be provided in each case instead of the three-way valves 24, 28. Finally, as already explained in part, an expansion element in the form of a TXV or EXV can optionally be arranged at the location of the expansion elements 26, 26 ', 22, 22'.

Overall, these and other advantageous implementations of a device 1, 2, in particular in connection with the operating strategy explained below, enable a fuel saving and an increase in performance over a comparatively large operating range. The operation of the refrigeration cycle 20 with both evaporators 29, 19 proves to be comparatively safe and allows a particularly advantageous and needs-based distribution of the power and refrigeration mass flows. Thus, e.g. On the one hand icing be avoided and on the other hand a needs-based and sufficient performance for cabin and engine are made available.

A method for cooling an essentially gaseous charging fluid provided for charging an internal combustion engine with a previously described circuit 100, 200 for charging an internal combustion engine is shown in FIG. 9 as a logic flow diagram in a particularly preferred embodiment and in FIG. 10 with associated temperature profiles for a coolant temperature T on the one hand or an operating state V1 for a first evaporator 29 - which symbolizes the activity of the evaporator 29 in the form of the HVAC evaporator for cooling an ambient air or cabin air (eg in recirculation mode) - and an operating state V2 - which the activity of a second evaporator 19 symbolizes a refrigerant for cooling the refrigerant in the form of the CAS evaporator. Overall, it is provided that the refrigerant bypass 33 for the second evaporator 19 is actuated in a first operating state B1 characterized by a coolant temperature lying below a limit temperature. The limit temperature is present in a range of 40 ° C to 50 ° C. In other words, the second evaporator 19 is inactive in this first operating state B1. The corresponding areas are indicated in FIG. 10 by B1. In this operating state B1, which can also be referred to as normal operation, the coolant temperature is preferably below the limit temperature of, for example, 40 ° to 55 ° C. Specifically, the CAS evaporator is not switched as a coupling element between the low-temperature cooling circuit and the refrigerant circuit or completely bypassed by the present refrigerant side bypass 33, actuated by the three-way valve 28. In a modified or alternative modification, a coolant-side bypass can be provided to the additional cooling effect of the second evaporator 19 is not required.

A power control - in particular for embodiments of FIGS. 1 to 3 - of the first evaporator 29, in this case in the form of the HVAC evaporator, takes place in this case via an EXV and TXV as expansion element 26 and further by measuring the pressure and temperature of the refrigerant , especially after the HVAC evaporator. As explained, the CAS evaporator is preferably bypassed on the refrigerant side by means of the bypass 33 and a corresponding position of the three-way valve 28. By virtue of the coolant-side decoupling of the three-way valve, the CAS evaporator as the second evaporator 19 can advantageously be kept at a comparatively low temperature level - similar to the temperature level of the HVAC evaporator as the first evaporator 29. By setting such a comparatively low refrigerant mass flow, the low temperature level can continue be favored. For example, this can be achieved by targeted opening - in the form of a low-frequency clocking - the shut-off valve on the CAS evaporator as the second evaporator 19. Another possibility is to obtain a very low refrigerant mass flow over a defined geometry in the expansion element 22 as a leak. As a result, the second evaporator 19 is as CAS evaporator in case of need, ie when additional charge air cooling power is required, at a relatively low temperature level. Such a low temperature level has a certain buffering effect when the second evaporator 19 is switched on, or allows a rapid cooling of the charge air - this before the coolant circuit with a coupled CAS evaporator would normally be started and would be in stationary operation. In addition, this measure has the advantage that the power consumption of a coolant pump 15, be it an electric or conventional coolant pump, is reduced due to the elimination of the coolant-side pressure drop of the CAS evaporator. As a result, fuel consumption is thus reduced.

In a second operating state B2 characterized by a coolant temperature lying above a limit temperature, two operating substates B21 and B22 for cooling the charging fluid or, more specifically, for operating the first evaporator 29 and the second evaporator 19 are possible.

In a first operating substate B21, neither the refrigerant bypass 33 for the second evaporator 19 nor the refrigerant bypass 31 for the first evaporator 29 is actuated. In the case of the second variant of the invention opens - as already explained above - the shut-off valve 28 'of the second evaporator 29. In other words, both evaporators 29, 19 are active. This operating sub-state is suitable for the case that a power requirement of the first and second evaporators 29, 19 is below a power limit of the coolant guide 10. In other words, it is for additional cooling of the coolant at a coolant temperature of more than 40 ⁰ C to 55 ° C, the CAS evaporator in the low-temperature cooling circuit and coupled to the refrigerant circuit for additional cooling of the coolant to the first evaporator 29 added. The first evaporator in the form of the HVAC evaporator remains switched on when the power at the CAS evaporator and the power of the HVAC evaporator does not exceed the total capacity of the refrigeration circuit. For example, the air inlet temperature and the air quantity can be used for the respective output of the evaporators 19, 29. This is known for example by an engine control unit and / or a climate control device. The power control of the HVAC evaporator via an EXV or TXV as explained above and / or by measuring the pressure and temperature of the refrigerant after the CAS evaporator. When using an electric expansion device 26 (EXV) on the HVAC evaporator, the decreased power on the HVAC evaporator can be varied according to the specification. The performance of the CAS evaporator can be regulated only comparatively poorly directly, but rather advantageously takes place indirectly through the HVAC evaporator.

When using a thermostatic expansion device 26 (TXV), the power dissipated is set by the setting, overheating depending on the suction pressure. In this case, the setting is prioritized on the HVAC evaporator so that the power left over from the HVAC evaporator - that is, the rest of unevaporated refrigerant - is available to the CAS evaporator. The refrigerant-side performance of the CAS evaporator can be adjusted in parallel by the coolant-side changeover valve in the form of the three-way valve - also referred to as three / two-way valve - by clocking the valve 28 and 24 a certain Kühlmit- telmassenstrom and thus a certain power decrease the coolant takes place.

In an operating substate B22, a power demand of the first and second evaporators is above a power limit of the refrigerant guide and the refrigerant bypass 33 for the second evaporator 19, and the refrigerant bypass 31 for the first evaporator 29 is operated mutually. In other words, this operation substate B22 corresponds to the case where the coolant temperature is more than 40 ⁰ C to 55 ° C and the power demand is too high. The CAS evaporator as Koppelglied between the low-temperature cooling circuit and the refrigerant circuit is indeed switched to additional cooling of the coolant, but there is an alternate operation of both evaporators 19, 29 due to the high power requirement of the CAS evaporator to the coolant and / or refrigerant circuit. The evaporators 19, 29 are switched on and off by the switching valves 24, 28 described above. A power control of the CAS evaporator takes place, for example, via a conventional thermostatic expansion element 26 (TXV) explained above or via a TXV with integrated shut-off function. At the same time, the first evaporator in the form of the HVAC evaporator is switched off or bypassed on the refrigerant side via a bypass line 31. In summary, the invention relates to a device 1 for cooling a coolant, which is provided for cooling a charging fluid for charging an internal combustion engine, with a refrigerant guide 20, in particular a refrigerant circuit, and a coolant guide 10, in particular a coolant circuit, the refrigerant guide 20 a first Evaporator 29 for a refrigerant for cooling an ambient air, a second evaporator 19 for a refrigerant for cooling the

Having coolant; the coolant guide 10 has a heat exchanger 11 for the charging fluid L, a coolant cooler 13, and the second evaporator 19 for the refrigerant of the refrigerant guide 20 for cooling the coolant. According to the concept of the invention, it is provided in a first variant that the first and the second evaporators 29, 19 are arranged in the refrigerant guide 20 in a row arrangement. In a second variant, it is provided that the first evaporator 29 and the second evaporator 19 are arranged in the refrigerant guide 20 in a parallel arrangement, wherein downstream of the second evaporator 19, a suction throttle 35 is arranged downstream of the refrigerant. Preferably, for controlling the capacity of the first and / or second evaporator 29, 19, a refrigerant bypass 30, 31, 33 is used for the first and / or second evaporator 29,

19th

Significant

1 facility

10 coolant guide

10 'bypass

10 "coolant line

11 thermal fluid, heat exchanger

13 coolant cooler

15 coolant pump

17 three-way valve

19 evaporator

20 refrigerant guide

21 refrigerant compressor

22 expansion organ

23 capacitor

24 three-way valve, shut-off valve

25 collection dryers

26 expander, three-way valve

28 Three-way valve, diverter valve, shut-off valve

29 first evaporator

30 refrigerant bypass, bypass route

31 Refrigerant Bypass, Bypass, Line

33 Refrigerant Bypass, Bypass, Refrigerant Bypass

40 measuring line

40 'pressure

40 "temperature, section

100 cycles

K cooling air

L charging fluid

A view

B view

B1 operating state

B21 operating state

B22 operating status

V1 operating state

V2 operating state

Claims

Patent claims

1. A device (1, 2) for cooling a coolant, which is provided for cooling a charging fluid (L) for charging an internal combustion engine, with a refrigerant guide (20), in particular a refrigerant circuit, and a coolant guide (10), in particular a coolant circuit; wherein - the refrigerant guide (20) has a first evaporator (29) for a refrigerant for cooling an ambient air, a second evaporator (19) for a refrigerant for cooling the refrigerant; - The coolant guide (10) has a heat exchanger (11) for the charging fluid (L), a coolant radiator (13), and the second evaporator (19) for the refrigerant of the refrigerant guide (20) for cooling the coolant;

characterized in that

(A) the first evaporator (29) and the second evaporator (19) in the refrigerant guide (20) are arranged in a series arrangement, or (B) the first evaporator (29) and the second evaporator (19) in the refrigerant guide (20) are arranged in parallel, in particular wherein the refrigerant downstream of the second evaporator (19), a suction throttle (35) is arranged.

2. Device (1) according to claim 1, characterized in that the second evaporator (19) is arranged downstream of the first refrigerant evaporator (29) or the first evaporator refrigerant downstream of the second evaporator are arranged (Alternative A).

3. Device (1) according to claim 1 or 2, characterized in that the first evaporator (29) and the second evaporator (19) in the refrigerant guide (20) are arranged in a row and refrigerant downstream from the first evaporator (29) and / or second evaporator (19) a suction throttle is arranged.

4. Device (1, 2) according to one of claims 1 to 3, characterized in that for the power control of the first and / or second evaporator (29,

19), the refrigerant guide (20) each having a refrigerant bypass (30, 31, 33) for the first and / or second evaporator (29, 19) (alternatives A, B), in particular in the refrigerant guide (20) in a series arrangement arranged first evaporator (29) and second evaporator (19) (Alternative A).

5. Device (1, 2) according to one of claims 1 to 4, characterized in that a refrigerant bypass (33) for the second evaporator (19) leads before or after the suction throttle (35) in the refrigerant guide (20) ( Alternative A, B), in particular in the refrigerant guide (20) in parallel arrangement arranged first evaporator (29) and second evaporator (19) (Alternative B).

6. Device (1, 2) according to one of claims 1 to 5, characterized in that a coolant bypass (10 ') for the second evaporator (19) and / or the first evaporator (29) in the coolant guide (10). is provided.

7. Device (1, 2) one of claims 1 to 6, characterized in that the refrigerant upstream of each of the first and / or second evaporator (29, 19) an actuating member (24, 24 ', 26, 26') in particular for actuating the Cold ittel-Bypasses (30, 31, 33) is arranged, in particular in each case a switching three-way valve and / or two Ab- shut-off valves and / or in each case a shut-off valve (24 ', 28') with an expansion element (22 ', 26').

8. Device (1, 2) according to one of claims 1 to 7, characterized in that

Means for power measurement of the first and / or second evaporator (29, 19) are provided.

9. Device (1, 2) according to one of claims 1 to 8, characterized in that the refrigerant upstream of the first evaporator (29) and / or the second evaporator (19) an expansion element (22, 22 ', 26, 26') is arranged is, in particular an electrical (EXV) and / or thermostatic (TXV) expansion element (22, 22 ', 26, 26'), in particular with shut-off function, in particular for power control of the first evaporator (29) and / or second evaporator (19 ).

10. Device (1, 2) according to one of claims 1 to 9, characterized in that the coolant guide (10) and / or coolant guide (20) has a sensor for determining the coolant temperature.

11. Device (1, 2) according to one of claims 1 to 10, characterized in that - lying in a first by a below a threshold temperature

Operating mode (B1) of the cold-medium by-pass (33) for the second evaporator (19) is actuated, or - in a second characterized by a lying above a temperature limit temperature coolant operating condition (B2) either neither the Kaltem ittel Bypass (33) for the second evaporator (19) nor the refrigerant bypass (31) for the first evaporator (29) is actuated (B21), or, in particular in the event that a power requirement of the first and second evaporator (29 , 19) is above a power limit of the refrigerant guide, the refrigerant bypass (33) for the second evaporator (19) and the Kaltel ittel-by-pass (31) for the first evaporator (29) is alternately operated (B22).

12. Device (1, 2) according to one of claims 1 to 11, characterized in that the heat exchanger (11) and the second evaporator (19) are realized separately or in a common structural unit, in particular the heat exchanger (11) separately from charging fluid (L) can be flowed through or in the unit with the second evaporator (19) of charging fluid (L) is arranged to flow through.

13. Circuit (100, 200) for charging an internal combustion engine, comprising: a compressor, in particular exhaust gas turbocharger, in a direction provided for the charging fluid flow guidance of a charging fluid (L); a device (1), coupled via the heat exchanger (11) for the charging fluid (L), according to one of the preceding claims.

14. Method (B) for cooling a substantially gaseous charging fluid (L) provided for charging an internal combustion engine, in particular a charge air and / or an exhaust gas or mixtures comprising a charge air and / or an exhaust gas, with a circuit (100, 200) for Charging the internal combustion engine according to claim 10 or a device according to any one of claims 1 to 12, characterized in that

- In a first characterized by a below a temperature limit temperature coolant operating condition (B1) of the refrigerant bypass (33) for the second evaporator (19) is actuated, or - in a second lying above a temperature limit

Operating mode (B2), either the refrigerant bypass (33) for the second evaporator (19) or the refrigerant bypass (31) for the first evaporator (29) is actuated either (B21), or in particular in the event that a power requirement of the first and second evaporator is above a performance limit of the refrigerant guide, the refrigerant bypass (33) for the second evaporator (19) and the refrigerant bypass (31) for the first evaporator (29 ) is operated alternately (B22).

15. The method according to claim 14, characterized in that the limit temperature is between 40 to 55 ° C.

16. The method according to claim 14 or 15, characterized in that a coolant bypass (10 ') is actuated to control the coolant temperature, in particular the coolant temperature thereto by means of the refrigerant guide (20) is readjusted.