DE102020001350B4 - Waste heat recovery system, powertrain and vehicle - Google Patents

Abstract

Waste heat recovery system (1) for a vehicle (3), the vehicle (3) comprising a power source (5) configured to provide power to the vehicle (3), and a power source cooler (7) configured to cool the power source (5) is configured, and wherein the waste heat recovery system (1) comprises: - a first evaporator (11) configured to collect heat generated by the power source (5), - a first expander (13) which is configured to provide useful work collected by the first evaporator (11), - a second evaporator (21), and - a second expander (23) configured to provide useful work collected by the second evaporator (21). wherein the second evaporator (21) is configured to collect heat dissipated from the power source cooler (7), characterized in that the system (1) comprises a first condenser (31) configured to condense working fluid is evaporated by the first evaporator (11), and that the first condenser (31) is configured to heat the second evaporator (21).

Description

The present disclosure relates to a waste heat recovery system for a vehicle. The present disclosure further relates to a powertrain with a waste heat recovery system for a vehicle and a vehicle comprising such a powertrain.

Some vehicles are equipped with a waste heat recovery system that uses waste heat from the vehicle's power source to generate useful work. A waste heat recovery system usually includes an evaporator arranged to evaporate a working fluid using waste heat and an expander arranged to provide useful work from evaporated working fluid. In addition, a waste heat recovery system usually includes a condenser located downstream of the expander and arranged to condense the working fluid before the working fluid is pumped into the evaporator. In order to condense the working medium, the condenser must be cooled.

The expander may be connected to a drive shaft of the vehicle to provide useful work in the form of drive torque of the drive shaft, or may be arranged to drive another device. In this way, the overall energy efficiency of the vehicle is improved.

Waste heat recovery systems offer several advantages in terms of vehicle energy efficiency, but there are many challenges in converting waste heat into useful work in vehicles without noticeably increasing the weight, cost and complexity of the vehicle. The efficiency of a waste heat recovery system depends in part on the temperature difference between the evaporator and the condenser. That is, the efficiency of the waste heat recovery system can be improved if the evaporator can collect a large amount of heat at a higher temperature level. Likewise, the efficiency of the waste heat recovery system can be improved if the condenser can be efficiently cooled to a lower temperature level.

Modern vehicles typically include numerous components and systems that generate excess heat. However, the temperature level of the heat is usually not sufficient to drive a separate waste heat recovery system that converts the excess heat into useful work. Additionally, as is the case with many other types of systems, a waste heat recovery system has a narrow operating range in which it operates most efficiently.

Additionally, in today's consumer market, it is generally advantageous for products such as vehicle systems and their associated components to have conditions and/or characteristics suitable for cost-effective manufacturing and assembly.

From the DE 10 2006 043 139 A1 a generic waste heat recovery system for a vehicle is known.

From US 2018/0 313 234 A1 a heat recovery system intended in particular for internal combustion engines is known, in which the heat from an intercooler is transferred to an evaporator through an air flow.

An object of the present invention is to eliminate, or at least reduce, at least some of the problems and disadvantages mentioned above.

According to a first aspect of the invention, the object is achieved by a waste heat recovery system for a vehicle, the vehicle comprising a power source configured to provide power to the vehicle and a power source cooler configured to cool the power source. The waste heat recovery system includes a first evaporator configured to collect heat generated by the power source, a first expander configured to provide useful work from heat collected by the first evaporator, a second evaporator, and a second expander , configured to provide useful work from heat collected by the second evaporator. The second evaporator is configured to collect heat dissipated from the power source cooler. The waste heat recovery system according to the invention is characterized in that it includes a first condenser configured to condense working medium evaporated from the first evaporator, and in that the first condenser is configured to heat the second evaporator. In this way, conditions are provided for further efficient conversion of heat into useful work and further improved overall energy efficiency of a vehicle that includes the waste heat recovery system. This is the case because the first capacitor is configured to heat the second evaporator and as a result the heat of the first capacitor can be converted into useful work by the second expander. In addition, a waste heat recovery system is provided Has conditions and properties that are suitable for cost-effective manufacturing and assembly. This is because the need for another arrangement that cools the first condenser is avoided.

Further, since the second evaporator is configured to collect heat dissipated from the power source cooler, the heat dissipated from the power source cooler can be efficiently converted into useful work by the second expander.

Additionally, since the system includes the first expander configured to provide useful work from heat collected by the first evaporator and the second expander configured to provide useful work from heat collected by the second evaporator , the first and second expanders can be easily designed to operate in an optimal operating range taking into account the temperature level and the level of heat collected by the respective first and second evaporators. Accordingly, in this way, the relatively small amount of heat dissipated by the power source cooler can be efficiently converted into useful work by the second expander. This provides conditions for more efficient conversion of heat into useful work and can improve the overall energy efficiency of a vehicle incorporating the system.

Accordingly, a waste heat recovery system is provided which eliminates or at least mitigates at least some of the problems and disadvantages mentioned above. As a result, the above-mentioned object is achieved.

Optionally, the power source cooler is configured to be exposed to an air flow having an air flow direction, with the second evaporator downstream of the power source cooler as viewed in the air flow direction. This allows the second evaporator to collect heat dissipated from the power source cooler in a simple and efficient manner, obviating the need for additional heat transfer devices or systems for transferring heat from the power source cooler to the second evaporator. This consequently provides a solution that is light in weight, low cost, and straightforward to collect heat dissipated from the power source cooler.

Optionally, the power source includes an internal combustion engine, wherein the first evaporator is configured to collect heat from exhaust gases of the internal combustion engine. This provides a waste heat recovery system in which the first expander can provide useful work from heat collected from a source having a large amount of heat.

Optionally, the power source includes an intercooler, wherein the second evaporator is configured to collect heat dissipated by the intercooler. This allows the relatively small amount of heat that is dissipated by the intercooler to be efficiently converted into useful work by the second expander.

Optionally, the second evaporator is arranged downstream of the charge air cooler as viewed in the air flow direction. This provides a solution that is lightweight, low cost and straightforward to collect heat dissipated by the intercooler.

Optionally, the system includes a first working medium circuit and a second working medium circuit, wherein the first evaporator and the first expander are arranged in the first working medium circuit and the second evaporator and the second expander are arranged in the second working medium circuit, and wherein the second working medium circuit comprises one working medium, the other Has properties as the working medium of the first working medium circuit. This provides a waste heat recovery system that has a more efficient conversion of heat from multiple heat sources into useful work. This is the case because the first working fluid circuit can convert heat from a source with a higher temperature level and the second working fluid circuit can efficiently convert heat from one or more sources with a lower temperature level, the respective first and second working fluid circuits being the same with respect to the temperature level and the amount of heat collected by the respective first and second evaporators can be easily optimized.

As a result, due to these features, conditions are provided for further efficient conversion of heat into useful work and further improved overall energy efficiency of a vehicle that includes the waste heat recovery system.

Optionally, the system includes a second condenser configured to condense working fluid evaporated from the second evaporator, the second condenser configured to be supplied by the power source cooler is cooled. This provides simple and efficient cooling of the second capacitor.

Optionally, the system includes an auxiliary cooler connected to an outlet of the power source cooler, and wherein the second capacitor is configured to be cooled by the auxiliary cooler. Thus, the second capacitor can be cooled to a lower temperature level with increased cooling efficiency. As a result, conditions are provided for further efficient conversion of heat into useful work and further improved overall energy efficiency of a vehicle incorporating the waste heat recovery system.

Optionally, the second evaporator and the first evaporator are provided in a heat exchanger unit. This provides efficient heat transfer between the first condenser and the second evaporator. Furthermore, a solution is provided that is light in weight, low in cost, and not complex to transfer heat between the first condenser and the second evaporator.

Optionally, the heat exchanger unit includes coolant channels of the first condenser and coolant channels of the second evaporator, the coolant channels of the first condenser being arranged in heat-exchanging contact with the coolant channels of the second evaporator. This provides efficient heat transfer between the first condenser and the second evaporator in a simple and efficient manner.

Optionally, the heat exchanger unit includes coolant channel pairs, each comprising a coolant channel of the first condenser and a coolant channel of the second evaporator. This provides efficient heat transfer between the first condenser and the second evaporator in a simple and efficient manner.

Optionally, the heat exchanger unit includes air channels between the coolant channel pairs. This allows air to flow through the heat exchanger unit via the air channels and provide heat to the second evaporator that is collected at the power source cooler to further heat the second evaporator in addition to the heat transferred via the coolant channel pairs. Additionally, the air flowing through the air channels may provide additional cooling of the first condenser in addition to the cooling provided via the coolant channel pairs. In this way, the energy efficiency of the waste heat recovery system can be further improved.

Optionally, the heat exchanger unit includes coolant channels that are shared by the first condenser and second evaporator. Since the heat exchanger unit includes coolant channels shared by the first condenser and second evaporator, further efficient heat transfer between the first condenser and the second evaporator is provided. This is because working medium of the first condenser and the second evaporator are mixed in the coolant channels of the heat exchanger unit. Furthermore, a solution is provided that is light in weight, low in cost, and not complex to transfer heat between the first condenser and the second evaporator.

Optionally, the system includes a second condenser configured to condense working fluid expanded by the second expander, the system including a mixer unit disposed upstream of the coolant channels, the mixer unit for mixing working fluid from the second condenser with working fluid from the first expander is configured. This makes it possible to provide efficient heat transfer between the working medium from the first expander and the working medium from the second capacitor. This is because further mixing of the working fluid occurs before the working fluid enters the coolant channels.

Optionally, the mixer unit is an inlet tank included in the heat exchanger unit. This provides a cost-effective and uncomplicated solution for further improving the heat transfer between the working medium from the first expander and the working medium from the second condenser.

Optionally, the system includes a first working fluid pump configured to pump working fluid to the first evaporator and a separation device configured to receive working fluid from the coolant channels, the separation device having a first outlet connected to the first working fluid pump, and a second outlet connected to the second expander, and wherein the separator is configured to separate liquid phase working medium to the first outlet and is configured to separate gaseous phase working medium to the second outlet. This causes the first working medium pump to become liquid with working medium in a gaseous state and the second expander is supplied with working medium in a gaseous state. As a result, the first working fluid pump can efficiently pump working fluid to the first evaporator, and the second expander can provide useful work from the gaseous working fluid.

Optionally, the separation device is a separation container that is contained in the heat exchanger unit. This provides a cost-effective and uncomplicated solution for separating gaseous working medium from liquid working medium.

Optionally, the system includes a subcooling passage between the first outlet and the first working fluid pump. This further ensures condensation of working medium and cavitation of working medium in the first working medium pump is further avoided.

Optionally, the heat exchanger unit includes the subcooling passage. This provides a cost-effective and uncomplicated solution for ensuring condensation of working medium and avoiding cavitation of working medium in the first working medium pump.

Optionally, the vehicle includes an air intake for directing ambient air to the power source radiator, the system including a cover assembly controllable between an open position in which the cover assembly allows air flow through the air inlet and a closed position in which the cover assembly allows air flow therethrough the air inlet is at least partially blocked. This provides a waste heat recovery system in which the temperature level of the power source cooler and the second evaporator as well as the heat transfer from the power source cooler to the second evaporator can be easily controlled by controlling the position of the cover assembly. In this way, conditions are provided for more efficient conversion of heat into useful work and the overall energy efficiency of a vehicle incorporating the system can be improved.

According to a second aspect of the invention, the object is achieved by a drive train for a vehicle, the drive train comprising a drive source configured to provide driving force to the vehicle, a drive source cooler configured to cool the drive source, and a waste heat recovery system according to the invention .

Since the drive train includes a waste heat recovery system according to the invention, a drive train is provided that can achieve a more efficient conversion of heat into useful work. As a result, the overall energy efficiency of a vehicle including such a powertrain can be improved.

Accordingly, a powertrain is provided which eliminates or at least reduces at least some of the problems and disadvantages mentioned above. As a result, the above-mentioned object is achieved.

According to a third aspect of the invention, the object is achieved by a vehicle which comprises a drive train with a waste heat recovery system according to the invention.

Since the vehicle includes a powertrain with a waste heat recovery system according to the invention, a vehicle is provided in which heat can be converted into useful work in a more efficient manner. As a result, a vehicle is provided that has conditions for improved energy efficiency.

Accordingly, a vehicle is provided which eliminates or at least reduces at least some of the problems and disadvantages mentioned above. As a result, the above-mentioned object is achieved.

Further features and advantages of the present invention will become apparent upon studying the appended claims and the detailed description below.

BRIEF DESCRIPTION OF DRAWINGS

• 1 einen Antriebsstrang gemäß einigen Ausführungsformen zeigt,
• 2 einen Antriebsstrang gemäß einigen weiteren Ausführungsformen zeigt,
• 3 einen Abschnitt einer in 2 dargestellten Wärmeaustauschereinheit zeigt,
• 4 einen Antriebsstrang gemäß einigen weiteren Ausführungsformen zeigt,
• 5 eine Wärmeaustauschereinheit gemäß in 4 dargestellten Ausführungsformen zeigt, und
• 6 ein Fahrzeug gemäß einigen Ausführungsformen zeigt.

Various aspects of the invention, including its particular features and advantages, can be readily understood from the exemplary embodiments set forth in the following detailed description and accompanying drawings, in which:

• 1 shows a powertrain according to some embodiments,
• 2 shows a drive train according to some further embodiments,
• 3 a section of an in 2 heat exchanger unit shown shows,
• 4 shows a drive train according to some further embodiments,
• 5 a heat exchanger unit according to in 4 illustrated embodiments shows, and
• 6 shows a vehicle according to some embodiments.

DETAILED DESCRIPTION

Aspects of the present invention are described in more detail below. The same numbers refer to the same elements throughout. Well-known functions or implementations are not necessarily described in detail for brevity and/or clarity.

1 illustrates a powertrain 60 according to some embodiments. The powertrain 60 includes a power source 5 configured to provide motive power to a vehicle that includes the powertrain 60. According to the illustrated embodiments, the drive source 5 comprises an internal combustion engine 5. The internal combustion engine 5 may be an internal combustion engine such as a compression ignition internal combustion engine, such as a diesel engine, or a gasoline engine with a spark ignition device, the gasoline engine being designed to operate with gasoline, gasoline, alcohol, similar fuels or combinations thereof can be configured. According to further embodiments of the present disclosure, the power source 5, as referred to herein, may include another type of power source 5 such as an electric drive system, a fuel cell, or the like.

The powertrain 60 further includes a power source cooler 7 configured to cool the power source 5. In addition, the powertrain 60 includes a waste heat recovery system 1 according to some embodiments. The waste heat recovery system 1 is referred to as “the system 1” in some places throughout this document for brevity and clarity. The waste heat recovery system 1 includes a first evaporator 11 configured to collect heat generated by the power source 5. According to the illustrated embodiments, the first evaporator 11 is configured to collect heat from exhaust gases of the internal combustion engine 5. Thus, according to the illustrated embodiments, the first evaporator 11 comprises a heat exchanger which is arranged in an exhaust line of the internal combustion engine 5. The exhaust pipe is in 1 not shown for the sake of brevity and clarity.

The waste heat recovery system 1 further includes a first expander 13 configured to provide useful work collected by the first evaporator 11. In addition, the waste heat recovery system 1 includes a second evaporator 21 and a second expander 23 configured to provide useful work from heat collected by the second evaporator 21. The second evaporator 21 is configured to collect heat dissipated from the power source cooler 7. This provides conditions for a more efficient conversion of heat into useful work. This is the case because the waste heat recovery system 1 includes two expanders 13, 23, each configured to provide useful work from heat collected by respective evaporators 11, 21 operating at different temperature levels. Accordingly, the expanders 13, 23 can be easily designed to operate at an optimal power output with respect to the level of heat collected by the respective evaporators 11, 21. In this way, the relatively small amount of heat dissipated by the power source cooler 7 can be efficiently converted into useful work by the second expander 23.

The power source cooler 7 is configured to be exposed to an air flow having an air flow direction d. According to the illustrated embodiments, the second evaporator 21 is arranged downstream of the drive source cooler 7, viewed in the air flow direction d. This allows the second evaporator 21 to collect heat dissipated from the power source cooler 7 in a simple and efficient manner, obviating the need for additional heat transfer devices or systems for transferring heat from the power source cooler 7 to the second evaporator 21. The air flow direction d may be opposite to a traveling direction of the vehicle including the waste heat recovery system 1 when the vehicle moves forward. Furthermore, according to the illustrated embodiments, the waste heat recovery system 1 includes a fan 30 configured to selectively generate an air flow in the air flow direction d. The fan 30 can be used, for example, at low speeds or at standstill of a vehicle that includes the waste heat recovery system 1 when the speed of the vehicle is not sufficient to generate an air flow in the air flow direction d. Alternatively or additionally, the fan 30 can be used, for example, when a cooling requirement of the power source cooler 7 exceeds a threshold value.

According to the illustrated embodiments, the drive source 5 comprises a charge air cooler 25. Thus, according to the illustrated embodiments, the drive source 5 is a supercharged internal combustion engine 5 having the charge air cooler 25. The second evaporator 21 is for Configured to collect heat that is dissipated by the intercooler 25. Thus, the relatively small amount of heat dissipated by the intercooler 25 can be efficiently converted into useful work by the second expander 23. According to the illustrated embodiments, the second evaporator 21 is arranged downstream of the charge air cooler 25, viewed in the air flow direction d. Thus, a solution is provided that is light in weight, low in cost, and is straightforward to collect heat dissipated from the intercooler 25. How out 1 As can be seen, according to the illustrated embodiments, the charge air cooler 25 is located upstream of the drive source cooler 7, viewed in the air flow direction d. In this way, it is ensured that compressed gas compressed by a charger of the power source 5 is efficiently cooled, while the heat of the compressed gas can be converted into useful work by the second expander 23. In this way, the overall energy efficiency of the powertrain 60 can be improved.

According to the illustrated embodiments, the system 1 comprises a first working medium circuit 51 and a second working medium circuit 52. The first evaporator 11 and the first expander 13 are arranged in the first working medium circuit 51. The first working medium circuit 51 further includes a first condenser 31 configured to condense working medium evaporated by the first evaporator 11. In addition, the first working medium circuit 51 includes a first working medium pump 17, which is configured to pump working medium via the first working medium circuit 51 in a direction from the first expander 13 to the first evaporator 11.

In the first evaporator 11, the working medium is heated to a temperature at which the working medium evaporates from the liquid phase into the gaseous phase. The gaseous working medium is transferred to the first expander 13. In the first expander 13, the temperature and pressure of the working medium is partially converted into useful work. According to the illustrated embodiments, a rotor of the first expander 13 is mechanically connected to a shaft of the drive source 5 via a gear 47. According to further embodiments, the first expander 13 may provide useful work in other ways, such as by driving an alternator that generates electricity or by operating a second device or system.

The working medium of the first working medium circuit 51 flows out of the first expander 13 and into the first capacitor 31. In the first capacitor 31, the temperature of the working medium is further reduced and gaseous working medium is condensed back into the liquid phase. The working medium is pumped from the first condenser 31 to the first evaporator 11 by the first working medium pump 17. In addition, the first working medium circuit 51 includes a first expansion vessel 57, which serves as a container containing a working medium and acts as a pressure vessel for the working medium in the first working medium circuit 51, which can facilitate the condensation of working medium even under operating conditions under which it is difficult to control the temperature of the working medium to reduce the working medium sufficiently.

According to the illustrated embodiments, the second evaporator 21 and the second expander 23 are arranged in the second working medium circuit 52. The second working medium circuit 52 further includes a second condenser 32 configured to condense working medium evaporated by the second evaporator 21. In addition, the second working medium circuit 52 includes a second working medium pump 18 configured to pump working medium via the second working medium circuit 52 in a direction from the second expander 23 to the second evaporator 21.

In the second evaporator 21, the working medium is heated to a temperature at which the working medium evaporates from the liquid phase into the gaseous phase. The gaseous working medium is transferred to the second expander 23. In the second expander 23, the temperature and pressure of the working medium is partially converted into useful work. According to the illustrated embodiments, a rotor of the second expander 23 is also mechanically connected to the shaft of the drive source 5 via the gear 47. Furthermore, according to the illustrated embodiments, the waste heat recovery system 1 includes a gear 49 between the rotor of the first expander 13 and the rotor of the second expander 23, which enables different speeds of rotation of the rotors of the first and second expanders 13, 23. In this way, the overall energy efficiency of the waste heat recovery system 1 can be further improved, as further explained in the present document. According to further embodiments, the second expander 23 may provide useful work in other ways, such as by driving an alternator that generates electricity or by operating a second device or system.

The working medium of the second working medium circuit 52 flows out of the second expander 23 and into the second capacitor 32. In the second capacitor 32, the temperature of the working medium medium is further reduced and the gaseous working medium is condensed back into the liquid phase. The working medium is pumped from the second condenser 32 into the second evaporator 21 by the second working medium pump 18. In addition, the second working medium circuit 52 includes a second expansion vessel 59, which serves as a container containing a working medium and acts as a pressure vessel for the working medium in the second working medium circuit 52, which can facilitate the condensation of working medium even under operating conditions under which it is difficult to control the temperature of the working medium to reduce the working medium sufficiently.

As can be seen from the present explanations, under most operating conditions, the working medium of the first working medium circuit 51 has a higher temperature than the working medium of the second working medium circuit 52. This is the case because the first evaporator 11 is for collecting heat at a higher temperature level is configured as the second evaporator 21. Thus, under most operating conditions, the components of the first working medium circuit 51 have a higher temperature than the components of the second working medium circuit 52. Therefore, “the first working medium circuit 51”, “the first evaporator 11” and “the “first capacitor 31,” as referred to herein, may also be referred to as “the high-temperature working fluid circuit 51,” “the high-temperature evaporator 11,” and “the high-temperature condenser 31.” Likewise, “the second working fluid circuit 52,” “the second evaporator 21,” and “the second condenser 32,” as referred to herein, may also be referred to as “the low-temperature working fluid circuit 52,” “the low-temperature evaporator 21,” and “the low-temperature -Capacitor 32”.

According to the illustrated embodiments, the second working medium circuit 52 comprises a working medium that has different properties than the working medium of the first working medium circuit 51, such as a lower boiling point. In this way, the efficiency of the respective working medium circuit 51, 52 can be increased and heat can be collected more efficiently by the respective first and second evaporators 11, 21 and can therefore also be converted more efficiently into useful work by the first and second expanders 13, 23.

According to the in 1 In the illustrated embodiments, the second capacitor 32 and the first capacitor 31 are configured to be cooled by the power source cooler 7. That is, the powertrain 60 according to the illustrated embodiments includes a power source cooling circuit 6 that includes the power source cooler 7, wherein the second capacitor 32 and the first capacitor 31 are configured to be cooled by the power source cooling circuit 6. The power source cooling circuit 6 includes coolant channels in the power source 5, a coolant pump 8 configured to pump coolant through the power source cooling circuit 6, and a first valve 10 arranged to direct coolant to the power source cooler 7 to a bypass line 12 connecting the power source cooler 7 bypasses.

According to the illustrated embodiments, the waste heat recovery system 1 includes an auxiliary cooler 35 connected to an outlet 7 ' of the power source cooler 7, the first and second condensers 31, 32 being configured to be cooled by the auxiliary cooler 35. This ensures that the first and second capacitors 31, 32 can be cooled efficiently, which provides conditions for increased efficiency of the waste heat recovery system 1. According to the illustrated embodiments, the waste heat recovery system 1 includes a fan 33 configured to selectively generate airflow through the auxiliary cooler 35. The fan 33 can be used, for example, during the standstill of a vehicle that includes the waste heat recovery system 1 and/or when a cooling requirement of the auxiliary cooler 35 exceeds a threshold value.

How out 1 As can be seen, according to the illustrated embodiments, the power source cooling circuit 6 includes a second valve 14, which is a three-way valve, which has a first inlet in fluid communication with the bypass line 12, a second inlet in fluid communication with the outlet 7 'of the power source cooler 7 stands, and includes an outlet that is in fluid communication with the coolant pump 8. Due to the second valve 14, the flow of the coolant to the first and second capacitors 31, 32 and thus also the cooling thereof can be controlled. As an alternative to the auxiliary cooler 35, the first and second capacitors 31, 32 can be cooled directly via the drive source cooler 7.

2 illustrates a powertrain 60 according to some further embodiments. In addition, the powertrain 60 according to FIGS 2 illustrated embodiments a waste heat recovery system 1 according to some further embodiments. The drive train 60 and the waste heat recovery system 1, shown in 2 , include the same features, functions and advantages as the powertrain 60 and the waste heat recovery system 1 according to the in 1 Illustrated embodiments, with some exceptions explained below.

According to the in 2 In the illustrated embodiments, the first capacitor 31 is configured to heat the second evaporator 21. Thus, in these embodiments, the first condenser 31 is in heat-exchanging contact with the second evaporator 21. Thereby, the heat dissipated from the first condenser 31 is transferred to the second evaporator 21 as a result of condensation of working medium in the first condenser 31 to form working medium in the second evaporator to evaporate. As a result, the energy efficiency of the waste heat recovery system 1 is further improved because the heat of the first capacitor 31 can be converted into useful work in the second expander 23.

According to the in 2 In the illustrated embodiments, the second capacitor 32 is configured to be cooled by the auxiliary cooler 35. As an alternative to the auxiliary cooler 35, the second capacitor 32 may be cooled directly by means of the power source cooler 7.

According to the in 2 In the embodiments shown, the second evaporator 21 and the first condenser 31 are provided in a heat exchanger unit 37. The heat exchanger unit 37 includes cooling channels 41 of the first condenser 31 and coolant channels 42 of the second evaporator 21. The coolant channels 41 of the first condenser 31 are arranged in heat-exchanging contact with the coolant channels 42 of the second evaporator 21.

3 represents a section of the in 2 heat exchanger unit 37 shown. Therefore, the following will be discussed at the same time 2 and 3 Referenced. How out 3 As can be seen, the heat exchanger unit 37 comprises pairs of cooling channels 39, each of which includes a coolant channel 41 of the first condenser 31 and a coolant channel 42 of the second evaporator 21. The coolant channels 41, 42 of the coolant channel pair 39 are arranged in adjacent contact to provide high thermal conductivity therebetween.

In addition, the heat exchanger unit 37 includes air channels 44 between the coolant channel pairs 39. In this way, air entering the in 2 indicated flow direction d flows, flow through the heat exchanger unit 37 and provide heat to the second evaporator 21, which is collected at the power source cooler 7 and the intercooler 25, to further heat the second evaporator 21 in addition to the heat transferred via the coolant channel pairs 39. Furthermore, the air flowing through the air channels 44 may provide additional cooling of the first condenser 31 in addition to the cooling provided via the coolant channel pairs 39. In this way, the energy efficiency of the waste heat recovery system 1 can be further improved.

4 illustrates a powertrain 60 according to some further embodiments. In addition, the powertrain 60 according to FIGS 4 illustrated embodiments a waste heat recovery system 1 according to some further embodiments. The drive train 60 and the waste heat recovery system 1, shown in 4 , include the same features, functions and advantages as the powertrain 60 and the waste heat recovery system according to the in 1 Illustrated embodiments, with some exceptions explained below.

According to the in 4 In the embodiments shown, the second evaporator 21 and the first condenser 31 are provided in a heat exchanger unit 37 '. In addition, the heat exchanger unit 37' includes coolant channels 46, which are shared by the first condenser 31 and the second evaporator 21. Therefore use according to the in 4 In the illustrated embodiments, the first condenser 31 and the second evaporator 21 share the same coolant channels 46 in the heat exchanger unit 37', which means that the working medium of the first condenser 31 and the second evaporator 21 is mixed in the coolant channels 46 of the heat exchanger unit 37'. Thus, according to the in 4 illustrated embodiments, the working medium of the first working medium circuit 51 and the second working medium circuit 51 is mixed in the coolant channels 46 of the heat exchanger unit 37 '.

5 represents the heat exchanger unit 37 'according to the in 4 illustrated embodiments. Therefore, the following will be discussed at the same time 4 and 5 Referenced. The waste heat recovery system 1 includes a mixer unit 48, which is arranged upstream of the coolant channels 46. According to the illustrated embodiments, the mixer unit 48 is an inlet container 48 contained in the heat exchanger unit 37. The mixer unit 48 is in fluid communication with the first working medium circuit 51 and the second working medium circuit 52. The mixer unit 48 is configured to receive working medium from the first expander 13 and working medium from the second expander 32, the mixer unit 48 for mixing the working medium from the second Capacitor 32 with the working medium from the first expander 13 is configured. Efficient heat transfer between the working medium from the first expander 13 and the working medium from the second capacitor 32 can thus be provided.

The working medium flows from the mixer device 48 into the coolant channels 46 of the heat exchanger unit 37 '. When flowing through the coolant channels 46, the working medium can receive heat therein or through air that passes through the heat exchanger unit 37 'into the in 4 indicated air flow direction d flows, is subjected to cooling.

As in 5 shown, the waste heat recovery system 1 includes a separation device 55 configured to receive working fluid from the coolant channels 46. According to the illustrated embodiments, the separation device 55 is a separation container 55 contained in the heat exchanger unit 37'. The separator 55 includes a first outlet 61. As best shown 4 As can be seen, the first outlet 61 is connected to the first working medium pump 17. In addition, the separating device 55, as in 4 and 5 shown a second outlet 62. How best to look 4 As can be seen, the second outlet 62 is connected to the second expander 23. The separation device 55 is configured to separate liquid phase working medium to the first outlet 61 and is configured to separate gaseous phase working medium to the second outlet 62. Thus, the first working medium pump 17 is supplied with working medium in the liquid state, and the second expander 23 is supplied with working medium in the gaseous state. As a result, the first working medium pump 17 can efficiently pump working medium to the first evaporator 11, and the second expander 23 can effectively provide useful work from the gaseous working medium.

According to the in 4 and 5 According to illustrated embodiments, the waste heat recovery system 1 includes a subcooling passage 65 between the first outlet 61 and the first working fluid pump 17. According to the illustrated embodiments, the heat exchanger unit 37' includes the subcooling passage 65. The subcooling passage 65 is configured to provide further cooling of working fluid coming from the first outlet 61 flows to the first working medium pump 17. Condensation of working medium is thus further ensured and cavitation of working medium in the first working medium pump 17 is further avoided.

According to the in 4 and 5 In the embodiments shown, the second working medium circuit 52 comprises a working medium that has different properties than the working medium of the first working medium circuit 51, such as a lower boiling point. In this way it can be ensured that the working medium of the first working medium circuit 51 evaporates the working medium of the second working medium circuit 52 in the heat exchanger unit 37 '. Equally, it can be ensured that the working medium of the second working medium circuit 52 evaporates the working medium of the first working medium circuit 51 in the heat exchanger unit 37 '.

According to the in 4 and 5 In the illustrated embodiments, the second capacitor 32 is configured to be cooled by the auxiliary cooler 35. As an alternative to the auxiliary cooler 35, the second capacitor 32 may be cooled directly by means of the power source cooler 7.

According to the in 1 , 2 and 4 In illustrative embodiments, the powertrain 60 includes an air inlet 71 for directing ambient air to the power source cooler 7. In addition, the waste heat recovery system 1 includes a cover assembly 73 controllable between an open position, in which the cover assembly 73 allows air flow through the air inlet 71, and a closed position is, in which the cover assembly 73 at least partially blocks the air flow through the air inlet 71. Thus, a waste heat recovery system 1 is provided in which the temperature level of the power source cooler 7 and the second evaporator 21 as well as the heat transfer from the power source cooler 7 and the intercooler 25 to the second evaporator 21 can be easily controlled by controlling the position of the cover assembly 73. In this way, conditions are provided for a more efficient conversion of heat into useful work, and the overall energy efficiency of a vehicle comprising the system 1 can be improved. In 1 and 3 1, the cover assembly 73 is shown in the open position. In 2 1, the cover assembly 73 is shown in the closed position. Furthermore, according to these embodiments, the powertrain 60 includes a cover 75 that encloses heat transfer surfaces of the intercooler 25, the power source cooler 7, the second evaporator 21, and/or the first condenser 3 in a manner that any air flowing into the air inlet 71 passes through the cover 75. Accordingly, the cover 75 acts as a barrier to prevent air flow around heat transferring surfaces of the intercooler 25, the power source cooler 7, the second evaporator 21 and/or the first condenser 3. This means that the heat transfer from the intercooler 25 and the power source cooler 7 to the second evaporator 21 increased.

According to the in 1 , 2 and 4 In the illustrated embodiments, the waste heat recovery system 1 may include a control arrangement configured to control the speed of the first working fluid pump 17 and the second working fluid pump 18. Such a tax arrangement is in 1 , 2 and 4 not shown for the sake of brevity and clarity. The control arrangement may be configured to control the speed of the first and second working medium pumps 17, 18 based on available heat in the first evaporator 11, available heat in the second evaporator 21, available cooling power of the first condenser 31 and/or available cooling power of the second condenser 32. Additionally, the control arrangement may be configured to control the first valve 10, the second valve 14, the cover arrangement 73 and/or one or more fans 30, 33. In this way, the conversion of heat into useful work can be carried out in an efficient manner, and the power distribution between the first and second working medium circuits 51, 52 can be controlled by controlling the speed of the first and second working medium pumps 17, 18.

The control arrangement, as referred to herein, may include a computing unit, which may take the form of substantially any type of processor circuit or microcomputer, for example a digital signal processing circuit (DSP), a central processing unit (CPU), a processing unit, processing circuit, processor, application specific integrated circuit (ASIC), microprocessor, or other processing logic that can interpret and execute instructions. As used herein, the term “computation unit” may represent a processing circuit that includes multiple processing circuits such as any, some, or all of those mentioned above.

One skilled in the art will recognize that the operating modes of the system 1 can be implemented by programmed instructions. These programmed instructions usually consist of a computer program which, when executed in the control arrangement, ensures that the control arrangement carries out the desired control, such as the operating modes of the system 1 described herein. The computer program is usually part of a computer program product that includes a suitable digital storage medium on which the computer program is stored.

The control arrangement can further comprise a storage unit, wherein the calculation unit can be connected to the storage unit, which can provide the calculation unit with, for example, stored program code and/or stored data that the calculation unit could need to carry out calculations. The calculation unit can also be designed to store partial or final results of calculations in the storage unit. The storage device may comprise a physical device used to store data or programs, i.e. H. May include sequences of instructions on a temporary or permanent basis. According to some embodiments, the memory device may include integrated circuits that include silicon-based transistors. The storage unit may, for example, be a memory card, flash memory, USB memory, hard drive or other volatile or non-volatile storage device for storing data such as ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable PROM), EEPROM (electrically erasable PROM), etc. in different embodiments.

The control arrangement is connected to components of the system 1 for receiving and/or sending input and output signals. These input and output signals may include waveforms, pulses, or other characteristics that the devices receiving input signals can recognize as information and that can be converted into signals processable by the control arrangement. These signals can then be delivered to the calculation unit. One or more devices emitting output signals may be arranged to convert calculation results from the calculation unit into output signals for transmission to other parts of the control system of the vehicle and/or the component or components for which the signals are intended. Each of the connections to respective components of the system 1 for receiving and sending input and output signals may take the form of one or more of a cable, a data bus, for example a CAN (Controller Area Network) bus, a MOST (Media Oriented Systems Transport bus or other bus configuration or wireless connection.

As described above, the system 1 may include one control arrangement, but may alternatively be fully or partially implemented in two or more control arrangements or two or more control units.

Control systems in modern vehicles generally include a communication bus system, which consists of one or more communication buses for connecting a number of electronic control units (ECUs), or controllers, to various components on board the vehicle. Such a control system may include a large number of control units and the performance of a particular function may be divided between two or more of them. Vehicles of the type described herein are therefore often equipped with significantly more control arrangements, as those skilled in the art will certainly recognize.

The computer product may, for example, be provided in the form of a data carrier that carries computer program code for carrying out at least some of the operating modes of the system 1 according to some embodiments when loaded into one or more calculation units of the control arrangement. The data carrier can, for example, be a CD-ROM or a ROM (read-only memory), a PROM (programmable read-only memory), an EPROM (erasable PROM), a flash memory, an EEPROM (electrically erasable PROM), a hard drive, a memory stick, an optical A storage device, a magnetic storage device, or any other medium, such as a disk or tape, that stores machine-readable data in a non-volatile manner. The computer program product may also be provided as computer program code on a server and may be downloaded remotely to the control arrangement, for example via an Internet or intranet connection or via other wired or wireless communication systems.

6 illustrates a vehicle 3 according to some embodiments. The vehicle 3 may include a powertrain 60 according to one of the embodiments shown in 1 , 2 and 4 are shown. The powertrain 60 is configured to provide motive power to the vehicle 3 via wheels 63 of the vehicle 3.

According to the illustrated embodiments, the vehicle 3 is a truck. According to further embodiments, the vehicle 3, as referred to herein, may be another type of manned or unmanned vehicle on land or water that relies on propulsion, such as a truck, a bus, a construction vehicle, a tractor, an automobile, etc ship, a boat or something similar.

It is to be understood that the foregoing is illustrative of various exemplary embodiments and that the invention is defined only by the accompanying claims. Those skilled in the art will recognize that the exemplary embodiments may be changed and that various features of the exemplary embodiments may be combined to create embodiments different from those described herein without departing from the scope of the present invention as set forth in the accompanying claims is defined.

The first evaporator 11 and/or the second evaporator 21 can also be referred to as heat collectors or boilers. The working medium, as referred to herein, may also be referred to as a working fluid.

In this document, the term 2 "comprising" or "having" is open and includes one or more mentioned features, elements, steps, components or functions, but excludes the presence or addition of one or more further features, elements, steps, components, functions or groups thereof.

Claims (14)

Waste heat recovery system (1) for a vehicle (3), the vehicle (3) comprising a power source (5) configured to provide power to the vehicle (3), and a power source cooler (7) configured to cool the power source (5) is configured, and wherein the waste heat recovery system (1) comprises: - a first evaporator (11) configured to collect heat generated by the power source (5), - a first expander (13) which is configured to provide useful work collected by the first evaporator (11), - a second evaporator (21), and - a second expander (23) configured to provide useful work collected by the second evaporator (21). wherein the second evaporator (21) is configured to collect heat dissipated from the power source cooler (7), characterized in that the system (1) comprises a first condenser (31) configured to condense working fluid is evaporated by the first evaporator (11), and that the first condenser (31) is configured to heat the second evaporator (21). System (1) after Claim 1 , wherein the power source cooler (7) is configured to be exposed to an air flow comprising an air flow direction (d), and wherein the second evaporator (21) is arranged downstream of the drive source cooler (7) viewed in the direction of the air flow direction (d). System (1) after Claim 1 or 2 , wherein the drive source (5) comprises an internal combustion engine (5), and wherein the first evaporator (11) is configured to collect heat from exhaust gases of the internal combustion engine (5). The system (1) according to any one of the preceding claims, wherein the power source (5) comprises an intercooler (25), and wherein the second evaporator (21) is configured to collect heat dissipated by the intercooler (25). System (1) according to one of the preceding claims, wherein the system (1) comprises a first working medium circuit (51) and a second working medium circuit (52), the first evaporator (11) and the first expander (13) in the first working medium circuit (51 ) are arranged and the second evaporator (21) and the second expander (23) are arranged in the second working medium circuit (52), and wherein the second working medium circuit (52) comprises a working medium which has different properties than the working medium of the first working medium circuit (51 ). System (1) after Claim 1 , wherein the second evaporator (21) and the first condenser (31) are provided in a heat exchanger unit (37, 37 '). System (1) after Claim 6 , wherein the heat exchanger unit (37) comprises coolant channels (41) of the first condenser (31) and coolant channels (42) of the second evaporator (21), and wherein the coolant channels (41) of the first condenser (31) are in heat-exchanging contact with the coolant channels ( 42) of the second evaporator (21) are arranged. System (1) after Claim 6 , wherein the heat exchanger unit (37 ') comprises coolant channels (46) which are shared by the first condenser (31) and the second evaporator (21). System (1) after Claim 8 , wherein the system (1) comprises a second condenser (32) configured to condense working medium expanded by the second expander (23), and wherein the system (1) comprises a mixer unit (48) corresponding to the coolant channels (46) is arranged upstream, wherein the mixer unit (48) is configured for mixing working medium from the first expander (13) with working medium from the second capacitor (32). System (1) after Claim 8 or 9 , wherein the system (1) comprises a first working medium pump (17) configured to pump working medium to the first evaporator (11), and a separator (55) configured to receive working medium from the coolant channels (46), wherein the separating device (55) comprises a first outlet (61) connected to the first working medium pump (17) and a second outlet (62) connected to the second expander (23), and wherein the separating device (55 ) is configured to separate working medium in liquid phase to the first outlet (61) and is configured to separate working medium in gaseous phase to the second outlet (62). System (1) after Claim 10 , wherein the system (1) comprises a subcooling passage (65) between the first outlet (61) and the first working medium pump (17). A system (1) according to any one of the preceding claims, wherein the vehicle (3) includes an air inlet (71) for directing ambient air to the power source cooler (7), and wherein the system (1) includes a cover assembly (73) positioned between an opened one Position in which the cover arrangement (73) allows air flow through the air inlet (71), and a closed position is controllable in which the cover arrangement (73) at least partially blocks the air flow through the air inlet (71). Powertrain (60) for a vehicle (3), the powertrain (60) comprising a power source (5) configured to provide power to the vehicle (3), and a power source cooler (7) configured to cool the power source ( 5) is configured, and comprises a waste heat recovery system (1) according to one of the preceding claims. Vehicle (3), which has a drive train (60). Claim 13 includes.

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