FIELD OF INVENTION

A vehicle thermal management system pertains to the systems for engine cooling, system for heating and cooling of the driving battery of a vehicle, and the air-conditioning system with several operating modes of air-conditioning of the passenger compartment, i.e. the system that provides cooling, heating, and dehumidifying of the space within the passenger compartment of the vehicle, and belongs to combined systems for heating and cooling, which operate in alteration or simultaneously, and also belongs to devices for circulation of cooling means which use ducts, as well as to the layout or instalment of the devices for heating, cooling or airing/refreshing the air in vehicle passenger compartments .

Int. Cl ⁸ .: B 60H 1/00 (2018.01 ); F 25B 29/00 (2018.01 ); F 25D 17/08 (2018.01)

TECHNICAL PROBLEM

The vehicle thermal management system according to the present invention is aimed at obtaining a novel system for vehicle thermal management with a new structure and layout of the system elements, which will simplify the setup of the system such that it will be realised using a shared cycle of the refrigerant, without switching valves for topology alternation of the refrigerant flow, at the same time enhancing the overall efficiency, reliability, and safety of the system.

STATE OF THE ART

Conventional systems for thermal management are known in internal combustion vehicles. The engine is cooled by heat exchange with the coolant flow, which is discharged by the coolant pump, flows through the engine, the heat exchanger for heating, and the radiator, back to the coolant pump. The radiator is equipped with a temperature sensitive valve, so that the heat exchange between the coolant and the environment is enabled only when the heating temperature is above a certain level. This allows for the waste heat of the engine to be used for heating the air that enters the passenger compartment, by exchanging the heat at the heat exchanger for heating.

At the same time, the system for heating, ventilation, and air conditioning (HVAC) of the passenger compartment of the vehicle contains an internal heat exchanger and a heating heat exchanger placed inside the internal air flow, with the heating heat exchanger placed in a part of the air flow after the internal heat exchanger. The air stream of the internal air flow, which originates from the environment, or from the passenger compartment, or is formed by mixing the air from these two sources, is first cooled in the internal heat exchanger to the dew-point in order to eliminate moisture from it. The distributor of the air flow divides the air stream of the internal air flow into two air streams, one of which is heated in the heating heat exchanger, while the other bypasses the heating heat exchanger, and the two air streams are, after passing through the flow mixer, led into the vehicle passenger compartment (cabin) as a single stream: the air stream entering the passenger compartment is a mixture of both air streams, the heated air stream and the air stream that bypasses the heating heat exchanger. Therefore, the temperature of the air stream fed into the vehicle cabin can be controlled by altering the relative quantity of the heated air stream in the total air flow.

The internal heat exchanger of the HVAC system is at the same time placed into the refrigerant circuit, formed by discharging the refrigerant from the discharge outlet of the compressor and its circulation from the external heat exchanger (condenser), adjustable expansion valve, internal heat exchanger (evaporator) and accumulator back to the compressor. The coolant cycle and the refrigerant circuit are thermally coupled by placement of the condenser immediately behind the radiator, so that the environmental air first exchanges the heat with the coolant flowing through the radiator, and then exchanges heat with the refrigerant in the external heat exchanger. This coupling is an inevitable consequence of the lack of space in the engine compartment of the vehicle, and inability to separate the condenser and the radiator, but has a negative impact on the efficiency of the refrigerant circuit.

However, modification of those systems for electrical and hybrid vehicles is associated with an array of problems, primarily due to high efficiency of the propulsion systems in those vehicles, limiting available waste heat. Additional heat sources are required for adequate heating of the passenger compartment, without compromising the overall efficiency of the system.

Conversely, cooling of the batteries of the hybrid and electrical vehicles by a passive heat exchange with the environment is often insufficient. This is especially the case when fast charging of the battery is used, which releases a significant amount of waste heat in a short time. At the same time, the safety of the fast charging requires that the battery temperature is maintained in a relatively narrow temperature range. It is thus necessary to treat the battery as a thermally managed vehicle system, i.e. it is necessary to ensure its active heating and cooling, independently of the environment temperature.

A particular problem is the safety of the hybrid and electrical vehicles associated with the malfunction of the thermal management system. Due to low mass of the propulsion assembly relatively to the waste heat it produces, a failure of the thermal management system can result in practically immediate overheating and failure of the vehicle propulsion. Therefore, the thermal management system for hybrid and electrical vehicles must ensure a safe and reliable cooling of the propulsion engine and electronic assembly. This was not the case for the internal combustion vehicles, where the large thermal mass of the propulsion system guaranteed sufficient time for the driver to react.

The vehicle thermal management system described in the United States patent US 9,908,382 B2 2018.03.06 ELECTRIC VEHICLE THERMAL MANAGEMENT SYSTEM of Thunder Power Hong Kong Ltd., (HK) represents an example of applying conventional thermal management systems in electric vehicles.

However, in order to meet all the additional technical requirements of the thermal management in electric vehicles, this solution introduces a significant number of additional components into the system. The temperature control of the vehicle battery is achieved by an additional flow of the coolant, in which an additional pump is included, an additional electric heater for pre-heating of the battery, and an additional refrigerant circuit for its cooling. A practical realisation of this system needs an additional electrical heater for heating the air that is fed into the passenger compartment.

Besides high complexity, that reduces the reliability, such a structure also limits the efficiency of the system, because the lacking heat for the passenger compartment is compensated for by electrical heaters. Known solutions of this problem further complicate the system by modifications of the cooling cycle of the HVAC system to enable operation in the heat-pump mode.

A thermal management system described in US 9,878,594 B2 2018.01.30 THERMAL MANAGEMENT SYSTEM FOR VEHICLE of Denso Corporation (JP) represents an example of an integrated system of vehicle thermal management. The system includes two coolant cycles, and one refrigerant circuit serving as a heat-pump. Instead of the radiator, an external heat exchanger is used, connected to enable thermal equilibration of the vehicle. The managed vehicle systems, heat-pump source, heat-pump sink, battery, and waste heat sources (propulsion engine and propulsion electronic assembly) are placed into independent parallel flows of the coolant. Two switching subsystems ensure the alteration of the coolant flow topology, in a way that enable each of the parallel coolant flows to be fed into one of the coolant cycles. Although this system is significantly simpler than the conventional systems for thermal management, it still has high complexity. Particularly, the two switching subsystems comprise a large number of valves, and malfunction of any one of them results to a complete malfunction of the system.

A particular shortcoming of this system is the topology with parallel flows of the coolant, where it is extremely hard to ensure a controlled flow through all parallel branches in every operating mode. Because of this, it can happen that the branch with the propulsion engine and the propulsion electronic assembly receives insufficient coolant flow for adequate cooling, resulting in their malfunction. Beside reduced reliability, such a situation represents a serious safety risk for passengers and the vehicle itself.

DESCRIPTION OF THE INVENTION

The aforementioned shortcomings of the existing systems for thermal management in vehicles are overcome by the proposed integrated system of thermal management where a change of the operating mode is achieved by an alternation of the coolant flow topology, and in which a reliable cooling of the waste heat source is ensured, i.e. of the propulsion engine and propulsion electronic assembly.

In the first embodiment of the present invention, the thermal management system includes a refrigerant circuit, a warm coolant flow path, a cold coolant flow path, a heat-exchange subsystem, and an operating mode selector subsystem with two operating modes. The managed vehicle systems are thermally coupled with the refrigerant circuit, so that they exchange heat with it.

The refrigerant circuit encompass a compressor for compressing and discharging the refrigerant, warm-flow heat exchanger which exchanges heat of the refrigerant with the warm coolant flow, the first adjustable expansion valve for throttling the refrigerant flow, and a cold-flow heat exchanger which exchanges heat of the refrigerant with the cold coolant flow. The refrigerant, which has been discharged from the outlet of the compressor, flows through the warm-flow heat exchanger, the first adjustable expansion valve, and the cold-flow heat exchanger to the inlet of the compressor. Thus, the refrigerant circuit serves as the heat-pump from the cold flow of the coolant to the warm flow of the coolant.

The heat-exchange subsystem is connected with the operating mode selector subsystem which, depending on the operating mode, can dispose it in the cold coolant flow path, or the warm flow of the coolant. The external heat exchanger, contained in the heat-exchange subsystem, allows for the heat exchange between the environment and the coolant which flows through the selected path.

When the emission mode is selected as the operating mode for the vehicle thermal management, the operating mode selector subsystem disposes the heat-exchange subsystem into the warm coolant flow path, allowing thus the excess heat from the managed vehicle systems, collected in the warm coolant flow, to be exchanged with the environment. Conversely, when the absorption mode selected as the operating mode for the vehicle thermal management, the operating mode selector subsystem disposes the heat-exchange subsystem into the cold coolant flow path, allowing thus the lack of heat in the managed vehicle systems to be exchanged from the environment into the cold coolant flow.

The said embodiment of the vehicle thermal management system allows for an arbitrary choice of the direction of heat exchange with the environment, which further allows for the thermal equilibration inside the vehicle independently of the environmental temperature. The operating mode selector subsystem has only two discrete states, which allows for a simple realisation. At the same time, the system is realised without coolant flow branching, independently of the selected operating mode, avoiding thus the need for a complicated system of flow resistances compensation in different branches of the coolant flow.

In a second embodiment of the present invention, the heat-exchange subsystem additionally contains a waste heat source, so that waste heat is exchanged with a coolant flowing through the path selected by the operating mode selector subsystem. Thus, the vehicle thermal management system provides the cooling of the waste heat sources to the temperature of the environment. At the same time, it is possible to use the collected waste heat to compensate for the lack of heat in the managed vehicle systems.

In a third embodiment of the present invention, the air-conditioning, heating, and cooling of the passenger compartment (the HVAC system) contains an air-heating heat exchanger, disposed into the warm coolant flow path, as well as an air-cooling heat exchanger, disposed into the cold coolant flow path. The air stream of the HVAC system is cooled in the air-cooling heat exchanger to the dew point, in order to eliminate moisture, and then heated to the desired temperature in the air-heating heat exchanger, before being fed into the passenger compartment. The thermal coupling of the HVAC system with the refrigerant circuit is realised through the air-heating heat exchanger and the air-cooling heat exchanger. Thus, the thermal management for the vehicle provides heat transfer from the air-cooling heat exchanger to the air-heating heat exchanger, as well as equilibration of the difference in the amount of heat.

In a fourth embodiment of the present invention, the refrigerant circuit includes a compressor for compressing and discharging the refrigerant, warm flow heat exchanger which exchanges heat with the warm coolant flow, a second adjustable expansion valve for throttling the flow of the refrigerant, medium-pressure heat exchanger, a first adjustable expansion valve for throttling the refrigerant flow, and a cold flow heat exchanger which exchanges heat with the cold coolant flow. The refrigerant, which has been discharged from the compressor outlet, flows through the warm flow heat exchanger, the second adjustable expansion valve, medium-pressure heat exchanger, first adjustable expansion valve, and the cold flow heat exchanger to the compressor inlet.

Simultaneously, the HVAC system includes an air-heating heat exchanger, disposed in the warm coolant flow path, as well as the medium-pressure heat exchanger. The air stream of the HVAC system is cooled at the medium-pressure heat exchanger to the dew point, in order to eliminate moisture, and then warmed up to the desired temperature at the air-heating heat exchanger, before being fed into the vehicle passenger compartment. If air dehumidification is not required, the medium-pressure heat exchanger can also be used as the heat radiator. Then, the air stream is first pre-hated on the medium-pressure heat exchanger, to be heated up to the desired temperature at the air-heating heat exchanger, before being fed into the passenger compartment.

In a fifth embodiment of the present invention, the refrigerant circuit includes a compressor for compressing and discharging the refrigerant, a warm flow heat exchanger which exchanges heat with the warm coolant flow, a third adjustable expansion valve for throttling the refrigerant flow, a battery heat exchanger, a second adjustable expansion valve for throttling the refrigerant flow, a medium-pressure heat exchanger, the first adjustable expansion valve for throttling the refrigerant flow, and the cold flow heat exchanger which exchanges heat with the cold coolant flow. The refrigerant, which has been discharged from the outlet of the compressor, flows through the warm flow heat exchanger, the adjustable third expansion valve, the battery heat exchanger, the second adjustable expansion valve, the medium-pressure heat exchanger, the first adjustable expansion valve, and the cold flow heat exchanger to the inlet of the compressor. Thus, the battery heat exchanger allows for maintaining the battery temperature, i.e. heating and cooling of the battery depending on the temperature of the battery itself.

In a sixth embodiment of the present invention, the operating mode selector subsystem allows for an additional safety operating mode. When the safety operating mode is selected as the operating mode of the vehicle thermal management system, the operating mode selector subsystem establishes the coolant flow through the heat-exchange subsystem, independent of either the warm coolant flow or the cold coolant flow. This provides a reliable cooling of the waste heat source solely by using the heat-exchange subsystem, and, partly, operating mode selector subsystem, which ensures a reliable operating mode when malfunction of certain parts of the system occurs.

In a seventh embodiment of the present invention, the heat-exchange subsystem includes a recuperation heat exchanger, which exchanges heat of the air flow that leaves the passenger compartment with the coolant that flows through the path selected by the operating mode selector subsystem.

When the cooling regime is selected as the working regime of the HVAC system, the temperature of the air stream that flows out of the passenger compartment is lower than the temperature of the environment, so that the coolant which flows through the path selected by the operating mode selector subsystem is additionally cooled. This reduces the required temperature difference between the warm coolant flow and cold coolant, and consequently increases the efficiency of the whole system.

Conversely, when the heating regime is chosen as the working regime of the HVAC system, the temperature of the air stream that flows out of the passenger compartment is higher than the temperature of the environment, so that the coolant which flows through the path selected by the operating mode selector subsystem is additionally heated. This allows for collecting of the waste heat from this air stream, which advantageously affects the efficiency of the whole system.

The heat exchanged on the recuperation heat exchanger is limited by the distributor of the air flow, coolant switch, or their combination. Limiting is required when the outside temperature is below 0°C, since otherwise freezing of the condensed water from air exiting the passenger compartment could happen. The flow distributors can be eliminated if the freezing of the condensed water is avoided by design characteristics of the recuperation heat-exchanger.

BRIEF DESCRIPTION OF DRAWINGS

The vehicle thermal management system according to the present invention is shown in the attached drawings, in which:

Figure 1 presents a schematic of the vehicle thermal management system according to the first embodiment of the present invention;

Figure 2 presents a schematic of the vehicle thermal management system according to the second embodiment of the present invention;

Figure 3 presents a schematic of the vehicle thermal management system according to the third embodiment of the present invention;

Figure 4 presents a schematic of the vehicle thermal management system according to the fourth embodiment of the present invention;

Figure 5 presents a schematic of the vehicle thermal management system according to the fifth embodiment of the present invention;

Figure 6 presents a schematic of the vehicle thermal management system according to the sixth embodiment of the present invention;

Figure 7 presents a schematic of the vehicle thermal management system according to the seventh embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERED EMBODIMENTS OF THE INVENTION

Further description of the preferred embodiments of the present invention presented in the attached figures is primarily for illustration, without intention to limit the invention, its use or application.

Figure 1 contains a schematic of the vehicle thermal management system according to the first embodiment of the present invention, which includes a refrigerant circuit 1 , heat-exchange subsystem 2, operating mode selector subsystem 3, warm coolant flow path 4, and cold coolant flow path 5.

The managed vehicle systems 10x (where x=1, 2 etc. n) are thermally coupled with the refrigerant circuit 1 , which includes a compressor 10, which compresses and discharges the refrigerant that flows through the warm flow heat exchanger 14, the first adjustable expansion valve 11 which releases the pressure of the refrigerant, and the cold flow heat exchanger 15. Thus, the refrigerant circuit 1 transfers heat from the cold coolant flow into the warm coolant flow.

Heat-exchange subsystem 2 is connected to the operating mode selector subsystem 3 which can dispose it, depending on the selected operating mode, in the first operating mode in the cold coolant flow path 5, or in the second operating mode in the warm coolant flow path 4. The external heat exchanger 20, included in the heat-exchange subsystem 2, allows for the heat exchange between the environment and the coolant that flows through the selected path.

Operating mode selector subsystem 3 includes a warm flow pump 31 which establishes and maintains circulation of the coolant in the warm coolant flow path 4, cold flow pump 32, which establishes and maintains circulation of the coolant in cold coolant flow path 5, the first operating mode valve 33 with two positions A and B, as well as the second operating mode valve 34 with two positions C and D.

When the absorption operating mode is chosen as the operating mode of the vehicle thermal management system, the first operating mode valve 33 in position A closes warm coolant flow path 4, separating it from the flow through the heat-exchange subsystem 2. Simultaneously, the second operating mode valve 34 in position D feeds the cold coolant flow path 5 through the heat-exchange subsystem 2. Thus, the heat lacking in the managed vehicle systems 10x is exchanged from the environment into the cold coolant flow at the external heat exchanger 20, where from it is, via cold coolant flow heat exchanger 15, fed into the refrigerant circuit 1.

Conversely, when the emission operating mode is chosen as the operating mode of the vehicle thermal management system, the first operating mode valve 33 in position B leads the warm coolant flow path 4 through the heat-exchange subsystem 2. Simultaneously, the second operating mode valve 34 in position C closes the cold coolant flow path 5, separating it from the flow through the heat-exchange subsystem 2. Thus, the excess heat in the managed vehicle systems 10x exchanged via the thermal coupling Q is transferred from the refrigerant circuit in the warm flow heat-exchanger 14 into the warm coolant flow path 4, where from it is exchanged into the environment at the external heat exchanger 20.

This design allows for thermal equilibration in the refrigerant circuit 1 and, consequently, in the managed vehicle systems 10x by exchanging heat in the heat-exchange subsystem, without alternating the structure of the thermal coupling Q of the refrigerant circuit 1 with the managed vehicle systems 10x or the structure of the refrigerant circuit 1 itself.

In Figure 2 is shown a schematic of the vehicle thermal management system according to the second embodiment of the present invention, which inside the heat-exchange subsystem 2 additionally includes waste heat sources 20x (where x=1, 2 etc. n). The coolant flow into the heat-exchange subsystem 2 first exchanges heat with the environment in the external heat exchanger 20, to subsequently exchange heat with the waste heat sources 20x (where x=1, 2 etc. n).

When the absorption operating mode is selected as the operating mode of the vehicle thermal management system, the cold coolant flow path 5 passes through the heat-exchange subsystem 2, so that the heat collected from the waste heat sources 20x, through the first operating mode valve 33 in position A and the second operating mode valve 34 in position D, is transferred into the refrigerant circuit 1 by the cold flow heat exchanger 15. The equilibrium of the required and available heat is achieved by exchange of the difference with the environment at the external heat exchanger 20. Simultaneously, the cold flow pump 32 establishes and maintains the circulation of the coolant in the cold coolant flow path 5, and consequently through waste heat sources 20x.

Conversely, when the emission operating mode is selected as the operating mode of the vehicle thermal management, the warm coolant flow path 4 through the first operating mode valve 33 in position B and the second operating mode valve 34 in position C, flows through the heat-exchange subsystem 2, so that the heat collected from the waste heat sources 20x, together with excess heat in the managed vehicle systems 10x, and the exchanged heat in the warm flow heat exchanger 14 is exchanged from the warm coolant flow path (4) with the environment at the external heat exchanger 20. Simultaneously, the warm flow pump 31 establishes and maintains the circulation of the coolant in the warm coolant flow path 4 and consequently through waste heat sources 20x.

Thus, the waste heat is from sources 20x taken away independently of the operating mode of the vehicle thermal management system. Simultaneously a controlled flow of the coolant is ensured through waste heat sources 20x by the cold flow pump 32 or the warm flow pump 31 , depending on the selected operating mode. In thermal management systems in electric vehicles, when the propulsion engine and propulsion electronic assembly are waste heat sources, this design provides a reliable cooling.

In Figure 3 is presented a schematic of the vehicle thermal management system according to the third embodiment of the present invention, which includes a HVAC system 6 of the vehicle and a battery temperature regulation subsystem 7, as the managed vehicle systems.

The HVAC system 6 is thermally coupled with the refrigerant cycle 1 by the air-heating heat exchanger 61 disposed in the warm coolant flow path 4, as well as the air-cooling heat exchanger 62 which is, together with the valve 63 of the air-cooling heat exchanger disposed in the cold coolant flow path 5. The air flow of the HVAC system 6 is cooled in the air-cooling heat exchanger 62 to the dew point in order to eliminate moisture, and subsequently warmed up to the desired temperature at the air-heating heat exchanger 61 , before being fed into the vehicle passenger compartment. The valve 63 of the air-cooling heat exchanger allows for a controlled heat exchange in the air-cooling heat exchanger 62, ensuring that the air temperature after the heat exchanger is above 0°C, since otherwise freezing could happen of the condensed water from the air entering the HVAC system 6.

The thermal coupling of the vehicle battery 70 with the refrigerant circuit 1 is achieved by using the first battery valve 71, second battery valve 72, and the third battery valve 73, ensuring that the battery temperature regulation subsystem 7 has two operating modes that can be selected independently from the operating mode of the vehicle thermal management system. When the heating operating mode is selected as the operating mode of the temperature regulation of the vehicle battery 70, the first battery valve 71 is feeding at least part of the warm coolant flow 4 through the vehicle battery 70 and the third battery valve 73. Simultaneously, the second battery valve 72 prevents the cold coolant flow 5 through the vehicle battery 70. Thus, the vehicle battery 70 is heated by the heat exchange with the coolant in the warm coolant flow path 4.

Conversely, when the cooling operating mode is selected as the operating mode of the temperature regulation of the vehicle battery 70, the first battery valve 71 prevents the warm coolant flow 4 through the vehicle battery 70. Simultaneously, the second battery valve 72 feeds at least part of the cold coolant flow 5 through the vehicle battery 70 and through the third battery valve 73. Thus, the vehicle battery 70 is cooled by heat exchange with the coolant in the cold coolant flow path 5.

The placement order of the heat exchangers of the managed vehicle systems into the warm coolant flow path 4 corresponds to the descending sequence of the expected working temperatures. Conversely, the placement order of the heat exchangers of the managed vehicle systems into the cold coolant flow path 5 corresponds to the increasing sequence of the expected working temperatures. This ordering of the heat-exchangers allows for a simpler control system, more resistant to imperfections of the control elements, although the system could be also realised with a different ordering.

In Figure 4 is presented a schematic of the vehicle thermal management system according to the fourth embodiment of the present invention, which includes the HVAC system 6 of the vehicle and a battery temperature regulation subsystem 7 as the managed systems of the vehicle.

The compressor 10 compresses and discharges the refrigerant which flows through the warm flow heat exchanger 14, the second adjustable expansion valve 12 which releases the pressure of the refrigerant, the evaporator 17, and the first adjustable expansion valve 11 which throttles the refrigerant flow through the cold flow heat exchanger 15. This forms the refrigerant cycle with constant topology, which combines the warm flow heat exchanger 14, evaporator 17, and the cold flow heat exchanger 15 into one entirety.

The HVAC system 6 is thermally coupled with the refrigerant circuit 1 by the air-heating heat exchanger 61 disposed in the warm coolant flow path 4, as well as the evaporator 17 which is together with the second adjustable expansion valve 12 disposed into the refrigerant circuit 1. The air flow of the HVAC system 6 is cooled in the evaporator 17 to the dew point in order to eliminate moisture, and then warmed up to the desired temperature in the air-heating heat-exchanger 61 , before being fed into the vehicle passenger compartment. If the air dehumidification is not required, the evaporator 17 can also be used as a heat radiator. Then, the air flow is first pre-heated in the evaporator 17, and then warmed up to the desired temperature in the air-heating heat exchanger 61 , before being fed into the vehicle passenger compartment.

In Figure 5 is shown a schematic of the vehicle thermal management system according to the fifth embodiment of the present invention.

The compressor 10 compresses and discharges the refrigerant which flows through the warm flow heat exchanger 14, the third adjustable expansion valve 13 which releases the pressure of the refrigerant, the battery heat exchanger 16, the second adjustable expansion valve 12 which releases the pressure of the refrigerant through the evaporator 17, and the first adjustable expansion valve 11 which throttles the refrigerant flow through the cold flow heat exchanger 15. This forms the refrigerant cycle with constant topology, which combines the warm flow heat exchanger 14, the battery heat exchanger 16, the evaporator 17, and the cold flow heat exchanger 15 into one entirety.

The vehicle battery 70 is connected to the battery heat exchanger 16. In this system, the direction of the heat exchange in the battery heat exchanger 16 depends on the relation between the vehicle battery 70 temperature and the refrigerant temperature.

The fixed structure of the refrigerant circuit 1 is made possible because both the battery heat exchanger 16 and the evaporator 17 are used as a constant temperature regulators, and at the same time the desired temperature of the warm coolant flow is above the desired temperature of the vehicle battery 70 (usually between 20°C and 30°C), which is in turn above the expected range of the desired air temperatures after the evaporator 17 (1 °C to 10°C, usually). This ensures that all adjustable expansion valves 11 , 12, 13 of the refrigerant circuit 1 are in a continuous operating mode, which advantageously affects their reliability and required working characteristics.

In Figure 6 is shown a schematic of the vehicle thermal management system according to the sixth embodiment of the present invention, containing an operating mode selector subsystem 3 with three operating modes.

Operating mode selector subsystem 3 includes the main pump 30 which establishes and maintains the coolant flow through the heat-exchange subsystem 2, the warm flow pump 31 which maintains the coolant circulation in the warm coolant flow path 4 when it is not provided by the main pump 30, the cold flow pump 32 which maintains the coolant circulation in the cold coolant flow path 5 when it is not provided by the main pump 30, the first operating mode valve 33 with two positions A and B, as well as the second operating mode valve 34 with two positions C and D.

When the absorption operating mode is selected as the operating mode of the vehicle thermal management system, the first operating mode valve 33 (in position A) separates the warm coolant flow path 4 from the flow that passes through the heat- exchange subsystem 2, while the second operating mode valve 34 (in position D) leads the cold coolant flow path 5 through the heat-exchange subsystem 2. Simultaneously, the warm flow pump 31 maintains the coolant circulation in the warm coolant flow path 4, whereas the main pump 30 maintains the coolant circulation in the cold coolant flow path 5 and through the heat-exchange subsystem 2.

Conversely, when the emission operating mode is selected as the operating mode of the vehicle thermal management system, the first operating mode valve 33 (in position B) feeds the warm coolant flow path 4 through the heat-exchange subsystem 2, while the second operating mode valve 34 (in position C) separates the cold coolant flow path 5 from the flow that passes through the heat-exchange subsystem 2. Simultaneously, the cold flow pump 32 maintains the circulation of the coolant in the cold coolant flow path 5, while the main pump 30 maintains the coolant circulation in the warm coolant flow path 4 and through the heat-exchange subsystem 2.

Alternatively, when the safety operating mode is selected as the operating mode of the vehicle thermal management system, the first operating mode valve 33 (in position A) separates the warm coolant flow path 4 from the flow that passes through the heat-exchange subsystem 2, while the second operating mode valve 34 (in position C) separates the cold coolant flow path 5 from the flow that passes through the heat-exchange subsystem 2. The main pump 30 establishes and maintains the coolant circulation through the heat-exchange subsystem 2. In this operating mode the vehicle thermal management system provides reliable cooling of the waste heat sources 20x using a minimal number of components, which ensures a safe operating mode when malfunction of certain parts of the system occurs. It is preferable that the safe operating mode to be the default operating mode of the vehicle thermal management system, or that the operating mode selector subsystem 3 ensures that this operating mode is selected even in the absence of control signals. This choice ensures that the system is safe even in the case of control signal leads failure (break, short circuit, etc.) or control unit malfunction.

In Figure 7 is shown a schematic of the vehicle thermal management system according to the seventh embodiment of the present invention, which includes a reliable operating mode selector subsystem 3 with three operating modes, and which, in the part critical for vehicle safety, uses only high-reliability components.

Operating mode selector subsystem 3 includes the main pump 30 which ensures the coolant flow through the heat-exchange subsystem 2, the warm flow pump 31 that maintains the circulation of the coolant in the warm coolant flow path 4 when it is not provided by the main pump 30, the cold flow pump 32 that maintains the circulation of the coolant in the cold coolant flow path 5 when it is not provided by the main pump 30, the first operating mode valve 33 and the first auxiliary operating mode valve 35 used to connect the heat-exchange subsystem 2 in the warm coolant flow path 4, as well as the second operating mode valve 34 and the second auxiliary operating mode valve 36 used to connect the heat-exchange subsystem 2 into the cold coolant flow path 5. The reliable cooling of the waste heat sources 20x is provided by the choice of reliable components for the external heat exchanger 20, the main pump 30, the first operating mode valve 33, the second operating mode valve 34, the first auxiliary operating mode valve 35, and the second auxiliary operating mode valve 36.

When the absorption operating mode is selected as the operating mode of the vehicle thermal management system, the first operating mode valve 33 (in position E) and the closed first auxiliary operating mode valve 35 separate the warm coolant flow path 4 from the flow that passes through the heat-exchange subsystem 2, while the second operating mode valve 34 (in position F) and the open second auxiliary operating mode valve 36 close the cold coolant flow path 5 through the heat-exchange subsystem 2. Simultaneously, the warm flow pump 31 maintains the coolant circulation in the warm coolant flow path 4, while the main pump 30 establishes and maintains the coolant circulation in the cold coolant flow path 5 through the heat-exchange subsystem 2.

Conversely, when the emission operating mode is selected as the operating mode of the vehicle thermal management system, the first operating mode valve 33 (in position F) and the open first auxiliary operating mode valve 35 close the warm coolant flow path 4 through the heat-exchange subsystem 2, while the second operating mode valve 34 (in position E) and the closed second auxiliary operating mode valve 36 separate the cold coolant flow path 5 from the flow that passes through the heat-exchange subsystem 2. Simultaneously, the cold flow pump 32 maintains the coolant circulation in the cold coolant flow path 5, while the main pump 30 establishes and maintains circulation of the coolant in the warm coolant flow path 4 and through the heat-exchange subsystem 2.

Alternatively, when the safety operating mode is selected as the operating mode of the vehicle thermal management system, the first operating mode valve 33 (in position E) and the closed first auxiliary operating mode valve 35 separate the warm coolant flow path 4 from the flow that passes through the heat-exchange subsystem 2, while the second operating mode valve 34 (in position E) and the closed second auxiliary operating mode valve 36 separate the cold coolant flow path 5 from the flow that passes through the heat-exchange subsystem 2. This ensures a reliable cooling of the waste heat sources 20x by using a minimal number of reliable components. Reference labels used in drawings

Refrigerant circuit

Heat-exchange subsystem

Operating mode selector subsystem

Warm coolant flow path

Cold coolant flow path

HVAC system of the vehicle

Battery temperature regulation subsystem

Compressor

The first adjustable expansion valve

The second adjustable expansion valve

The third adjustable expansion valve

Warm flow heat exchanger

Cold flow heat exchanger

Battery heat exchanger

Evaporator

External heat exchanger

Main pump

Warm flow pump

Cold flow pump

The first operating mode valve

The second operating mode valve

The first auxiliary operating mode valve

The second auxiliary operating mode valve

Air-heating heat exchanger

Air-cooling heat exchanger

Valve of the air-cooling heat exchanger - Vehicle battery

- The first battery valve

- The second battery valve

- The third battery valve

102. ... 10n - Managed vehicle systems

202. ... 20n - Waste heat sources