IT202100022877A1 - IMPROVED HEAT MANAGEMENT SYSTEM FOR A FUEL CELL VEHICLE - Google Patents

Description

DESCRIPTION

of the patent for industrial invention entitled: ?IMPROVED HEAT MANAGEMENT SYSTEM FOR A FUEL CELL VEHICLE"

TECHNICAL FIELD

The present invention relates to a heat management system, in particular a heat management system for a fuel cell vehicle.

The present invention finds its preferred, though not exclusive, application in a heavy vehicle such as a truck; will you do? reference to this application by way of example below.

BACKGROUND OF THE INVENTION

Fuel cell vehicles include fuel cell modules that must be maintained within a pre-set temperature range. Consequently, the fuel cell modules have to be cooled or have to be heated depending on the vehicle operation and environmental conditions.

Furthermore, this need? common to other vehicle operating modules such as brake resistors, cabin or battery modules.

To provide correct management of the temperatures of all these elements, each of them ? equipped with a specific heat management system which includes the presence of heat exchangers, expansion tanks and ventilation means.

The aforementioned heat management systems clearly increase the complexity of the heat management systems. of the vehicle, reduce the useful spaces on it and increase manufacturing costs.

Furthermore, the use of known heat management systems involves the use of electrical energy thus reducing the efficiency of the vehicle.

Therefore, there ? the need to manage heat transfer in fuel cell vehicles to improve system efficiency by saving costs, reducing footprint and enabling the operation of various vehicle operating systems.

An object of the present invention ? meet the needs? mentioned above in an economical and optimized way.

SUMMARY OF THE INVENTION

The aforementioned object is achieved by a heat management system as claimed in the appended set of claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, below ? described a preferred embodiment, by way of non-limiting example, with reference to the attached drawings in which:

? figure 1 ? a hydraulic diagram of the heat management system according to the invention;

? figure 2 ? a hydraulic diagram of the heat management system according to the invention in a first operating condition;

? figure 3 ? a hydraulic diagram of the heat management system according to the invention in a second operating condition;

? figure 4 ? a hydraulic diagram of the heat management system according to the invention in a third operating condition;

? figure 5 ? a hydraulic diagram of the heat management system according to the invention in a fourth operating condition;

? figure 6 ? a hydraulic diagram of the heat management system according to the invention in a fifth operating condition; And

? figure 7 ? a hydraulic diagram of the heat management system according to the invention in a sixth operating condition.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 schematically describes a heat management system 1 for a heavy vehicle such as a truck (not shown).

Does the heavy vehicle include a fuel cell module 2 which ? configured, as is known, to supply electrical energy via a chemical reaction between hydrogen and oxygen.

The heavy vehicle further comprises a battery module 3 configured to store and allow the use of the electrical energy supplied by the fuel cell module 2.

The heavy vehicle also comprises braking resistor means 4 configured to impart a braking torque to a rotating shaft, to brake the vehicle, by producing electrical energy and dissipating it in the form of heat.

The heavy vehicle? equipped with a cabin (not shown) for accommodating a driver during use of the vehicle and therefore the heavy vehicle includes a cabin heater 5 configured to provide heat to the accommodation space of the cabin.

According to the invention, the heat management system 1 ? configured to fluidly connect together, at least indirectly, the fuel cell module 2, the battery module 3, the braking resistor means 4, the cabin heater 5, a plurality of of heat exchanger 6, 7, 8 and at least one expansion tank 9 through a plurality? of ducts and valve means for allowing heat transfer between the fuel cell module 4, the battery module 3, the braking resistor means 4 and the cabin heater 5 as a function of their temperature and their operating state .

In detail, according to the described advantageous embodiment represented in Figure 1, the heat management system 1 comprises a portion of fuel cells 1' comprising a first duct 11 and a second duct 12 which connect the fuel cells 2 and a fluid level fuel cell cooler 6' in series with each other.

The fuel cell portion 1' can? further comprising a bypass conduit 13 interposed at fluid level between the first and second conduits 11, 12 in parallel with the fuel cell radiator 6' to bypass the latter. Advantageously, the bypass duct 13 is connected at fluid level to the second duct 12 through a T junction while ? connected to the first conduit 11 by valve means 14 configured to flow the fluid to the fuel cell cooler 6' and the bypass conduit 13.

Furthermore, the fuel cell portion 1' ? equipped with pumping means 15 interposed at fluid level in one of the first and second conduits 11, 12, in the embodiment described in the second conduit 12, and configured to recirculate the refrigerant flow between the conduits 11, 12 and 13, in particular from the fuel cell cooler 6' to the fuel cell module 2.

The fuel cell portion 1' can? further comprise a fuel cell expansion tank 9' connected at fluid level to one of the first and second conduits 11, 12, in the embodiment described to the second conduit 12, upstream of the valve means 15 and configured to allow the expansion of conditioning fluid according to its temperature, as per s? known.

The heat management system 1 comprises a battery portion 1'' comprising a first duct 21 and a second duct 22 which fluidly connect the battery module 3 and a battery radiator 6'' in series with each other to the other.

The battery portion 1'' further comprises a bypass conduit 23 interposed at the fluid level between the first and second conduits 21, 22 in parallel with respect to the battery radiator 6'' to bypass the latter. Advantageously, the bypass duct 23 is connected at fluid level to the second conduit 22 via a T junction while ? connected to the first duct 21 through valve means 24 configured to make the fluid flow towards the battery radiator 6'' or the bypass duct 23. The battery portion 1'' further comprises a cooler 7 interposed at the fluid level on the duct of bypass 23.

It should be noted that cooler 7 means a radiator equipped with conditioning means for actively sucking the heat into the environment while a passive heat sink ? conceived as a simple radiator equipped with ventilation means to suck heat into the environment without the use of an air conditioning cycle device.

Also, the 1'' drum portion? equipped with pumping means 25 interposed at fluid level in one of the first and second conduits 21, 22, in the embodiment described in the first conduit 21, and configured to recirculate the refrigerant flow between the conduits 21, 22 and 23, in particular from the battery radiator 6'' towards the battery module 4.

The 1'' battery portion can? further comprise a battery expansion tank 9'' connected at fluid level to one of the first and second conduits 21, 22, in the embodiment described to the first conduit 21, upstream of the pumping means 25 and configured to allow the expansion of the conditioning fluid according to its temperature, as per s? known.

The heat management system 1 comprises a braking resistor portion 1''' comprising a first duct 31 and a second duct 32 which connect at fluid level the cabin heater 5 and the braking resistor means 4 in series the one over the other.

The portion of the braking resistor 1''' ? equipped with pumping means 33 interposed at fluid level in one of the first and second conduits 31, 32, in the embodiment described in the second conduit 32, and configured to recirculate the coolant flow between the conduits 31 and 32, in particular from the cabin heater 5 towards the braking resistor means 4.

The portion of the braking resistor 1'' can? further comprise a braking resistor expansion tank 9'' connected at fluid level to one of the first and second conduits 31, 32, in the embodiment described to the second conduit 32 upstream of the pumping means 33, and configured to allow the expansion of the conditioning fluid according to its temperature, as per s? known.

The braking resistor portion 1''' and the fuel cell portion 1', so? how the battery portion 1'' and the fuel cell portion 1' are fluidly separated from each other, i.e. the conditioning fluid of the fuel cell portion 1' ? different than the conditioning fluid flowing in the braking resistor portion 1''' and the battery portion 1''.

In particular, the braking resistor portion 1''' comprises a heat exchanger 8 configured to allow heat transfer between the conditioning fluids flowing in the fuel cell portion 1' and in the braking resistor portion 1' ''. Consequently, the heat exchanger 8 ? designed to keep the two conditioning fluid streams separate from each other.

In the embodiment described, according to the above configuration, the heat exchanger 8 is a counterflow heat exchanger.

Advantageously, the braking resistor portion 1''' and the battery portion 1'' are connected at the fluid level via a plurality of of connecting ducts 41, 42, 43, 44, as described below, therefore the conditioning fluid flowing in the braking resistor portion 1''' and in the battery portion 1'' ? the same.

In detail, the heat management system 1 comprises a first connection duct 41 configured to connect at the fluid level a point on the second duct 32 of the braking resistor portion 1''' interposed at the fluid level between the heat exchanger 8 and the cabin heater 5, preferably via a T joint, to the second duct 22 of the battery portion 1'' downstream of the battery radiator 6'', preferably via valve means 41'.

Furthermore, the heat management system 1 comprises a second connecting duct 42 configured to connect at fluid level a point on the first connecting duct 41, preferably via a T-joint, to the first duct 21 of the battery portion 1'' at a point interposed at the fluid level between the battery module 3 and the battery radiator 6'', preferably via valve means 42'. The second connecting duct 42 ? further fluid-level connected between the aforementioned T-joint and the valve means 42 to the second conduit 32 of the braking resistor portion 1'''.

Furthermore, the heat management system 1 comprises a third connection conduit 43 configured to connect at a fluid level a point on the second conduit 32 of the brake resistor portion 1''' interposed at a fluid level between the connection of the second conduit of connection 42 and the braking resistor expansion tank 9'', preferably via a T joint, to the first duct 21 of the battery portion 1'' at a point interposed at fluid level between the battery expansion tank 9'' and the 6'' battery cooler, preferably via a T-joint.

Furthermore, the heat management system 1 comprises a fourth connection conduit 44 configured to connect at a fluid level a point on the first conduit 31 of the braking resistor portion 1''' interposed at a fluid level between the connection of the third conduit connection 43 and the braking resistor expansion tank 9''' (and as shown preferably coincident with its fluidic connection point), preferably via a T-joint, to the second duct 22 of the battery portion 1'' in a point interposed at the fluid level between the battery radiator 6'' and the bypass duct 23, preferably via valve means 44'.

The heat management system 1 ? also equipped with shut-off (on-off) valves configured to allow or consequently prevent the flow of fluid on the respective conduit.

In particular, according to the configuration described, the heat management system 1 comprises:

- a first valve 31' interposed at fluid level on the second duct 32 of the braking resistor portion 1''' between the connection of the second connection duct 42 and the heat exchanger 8;

- a second valve 31'' interposed at fluid level on the first duct 31 of the braking resistor portion 1''' between the connection of the third connecting duct 43 and the cabin heater 5;

- a third valve 41'' interposed at fluid level on the first connection duct 41 between the connection of the second connection duct 42 and the braking resistor portion 1''';

- a fourth valve 42'' interposed at fluid level on the second connection duct 42 between the connection to the first connection duct 41 and the braking resistor portion 1'''; And

- a fifth valve 43' interposed at fluid level on the third connection duct 43.

The aforementioned valves and pumping means described in the portions and conduits are preferably electrically controlled via a unit control unit, not shown, configured to vary its state.

In particular, the work vehicle ? equipped with temperature sensor means configured to detect the temperature of the fuel cell module 2, of the battery module 3, of the braking resistor means 4 and of the cabin heater 5. These sensor means are electrically connected to the unit? electronic control system comprising processing means suitable for processing the temperature value sensed by the latter and for consequently controlling the valves and pumping means of the heat management system 1.

Does the heat management system 1 described above work? the following.

According to a first modality? operational, shown in Figure 2, it is noted that the fuel cell module 2 is below a lower temperature threshold, i.e. ? too cold. Accordingly, the braking resistor means 4 supplies a heat flow inside the braking resistor portion 1''' to the conditioning fluid flowing therein. In particular, the valves 41'', 42'', 43', 44' and 42' do not allow the fluid to pass through them and therefore the conditioning fluid only flows in the ducts 31, 32 carried by the pumping means 33. The heated conditioning fluid from the braking resistor means 4 passes through the heat exchanger 8 providing a heat flow to the fuel cell module which increases its temperature. This condition can be maintained for how long? necessary to raise the temperature above the lower threshold mentioned above. As shown, the heat flux provided by the braking resistor means 4 can also be used by passing it into the cabin heater 5 to provide a heat flow to the vehicle cabin, if the latter is also ? too cold. During this operation, the battery portion 1'' ? isolated from the other operation and the valve means 14 is controlled to bypass the fuel cell cooler 6'.

According to a second modality? operation, shown in FIG. 3 , it can be seen that the fuel cell module 2 and the battery module 3 are below respective lower temperature thresholds, i.e. they are too cold. Accordingly, the braking resistor means 4 supplies a heat flow inside the braking resistor portion 1''' to the conditioning fluid flowing therein. In particular, the valves 41'', 42'', 43' do not allow the fluid to pass through them while the valves 42' and 44' allow the passage inside the battery portion 1''. Thus, the heated conditioning fluid from the braking resistor means 4 passes through the heat exchanger 8 providing a heat flow to the fuel cell module which increases its temperature while part is diverted into the conduit 21 thus being pumped to battery module 3 while also increasing its temperature. These two flows then join together upstream of the pumping means 13 and are sent again towards the braking resistance means 4. This condition can? be maintained as long as necessary to raise the temperature above the lower thresholds mentioned above. As shown, the heat flux provided by the braking resistor means 4 can also be used by passing it into the cabin heater 5 to provide a heat flow in the vehicle cabin, if the latter is also ? too cold. Meanwhile, the valve means 14 is controlled to bypass the fuel cell cooler 6'.

According to a third modality? operation, shown in Figure 4, it is noted that the fuel cell module 2 and the battery module 3 are above respective upper temperature thresholds, i.e. they are too hot, while the braking resistor means 4 are not in function. In particular, the valves 24 and 42' are controlled to allow the circulation of conditioning fluid only between the cooler 7 and the battery module 3 while the valves 41', 43', 31', 41'' are controlled to include in the braking resistor portion 1'' also the battery heat exchanger 6''. Instead, the valve means 14 is controlled to cause a large part of the flow of conditioning fluid to flow into the fuel cell cooler 6'. Then the heat from the battery module 3 is transferred to the conditioning fluid flowing to the cooler 7 where it is dissipated into the environment. Instead, the fuel cell module 2 supplies heat to the conditioning fluid flowing to the fuel cell radiator 6', which dissipates the heat to the environment. While returning to the fuel cell module, some of the conditioning fluid flows to the heat exchanger 8 sub-cooling and thus providing a heat flow to the braking resistor portion 1'''. In the latter, this heat flows towards the 6'' battery radiator and from there? is dissipated into the environment. If necessary, part of this heat could be used in cabin heater 5.

According to a fourth modality? operation, shown in Figure 5, it is noted that the fuel cell module 2 and the battery module 3 are above their respective upper temperature thresholds, i.e. they are too hot, while the braking resistor means 4 are in operation . In particular, the valves 24 and 42' are controlled to allow circulation of the conditioning fluid only between the cooler 7 and the battery module 3 while the valves 41', 43', 42'' are controlled to include in the resistance portion of braking 1''' also the battery heat exchanger 6'' and to exclude the heat exchanger 8. The valve means 14 are instead controlled to ensure that a large part of the flow of conditioning fluid flows in the radiator of fuel cells 6'. Then, the heat from the battery module 3 is transferred to the conditioning fluid flowing to the cooler 7 where it is dissipated to the environment. Instead, the fuel cell module 2 supplies heat to the conditioning fluid flowing to the fuel cell radiator 6' which dissipates the heat to the environment. On the other hand, the braking resistor means 4 supplies heat to the conditioning fluid which flows towards the battery radiator 6'' and ? dissipated in the environment. If necessary, part of this heat could be used in the cabin heater 5. In this case, not shown in the drawings, the valve 31'' ? open. According to a fifth modality? operation, shown in Figure 6, it is noted that the fuel cell module 2 and the battery module 3 are above respective upper temperature thresholds, i.e. they are too hot, while the braking resistor means 4 are not in function. In particular, the valves 24 and 42' are controlled to allow the circulation of conditioning fluid only between the cooler 7 and the battery module 3 while the valves 41', 43', 42'' are controlled to include in the resistance portion of braking 1''' also the battery heat exchanger 6'' and to exclude the heat exchanger 8. The valve means 14 are instead controlled to ensure that a large part of the flow of conditioning fluid flows in the radiator of fuel cells 6'. Then the heat from the battery module 3 is transferred to the conditioning fluid flowing to the cooler 7 where it is dissipated into the environment. Instead, the fuel cell module 2 supplies heat to the conditioning fluid flowing to the fuel cell radiator 6' which dissipates the heat to the environment.

On the other hand, the conditioning fluid flows for safety reasons in the braking resistor portion 1''' without providing heat exchanges.

According to a sixth modality? operation, shown in Figure 7, it is noted that the fuel cell module 2 and the battery module 3 are above respective upper temperature thresholds, i.e. they are too hot, while the braking resistor means 4 are not in function. In particular, the valves 24 and 42' are controlled to allow the circulation of conditioning fluid only between the battery radiator 6'' and the battery module 3 while the valves 41'', 43', 31'' are controlled to circulate the conditioning fluid in the braking resistor portion 1''' only between the braking resistor means 4 and the cabin heater 5. The valve means 14, on the other hand, is controlled so that a large part of the flow of conditioning fluid flows into the fuel cell cooler 6'. Then the heat coming from the battery module 3 is transferred to the conditioning fluid which flows towards the battery radiator 6'' where it is dissipated into the environment. Instead, the fuel cell module 2 supplies heat to the conditioning fluid flowing to the fuel cell radiator 6' which dissipates the heat to the environment. On the other hand, the conditioning fluid flows for safety reasons in the braking resistor portion 1''' without providing heat exchanges.

In view of the foregoing, the advantages of a heat management system for a fuel cell vehicle according to the invention are evident.

Thanks to the proposed heat management system in which all operating elements of the vehicle are fluidly connected together, ? It is possible to efficiently allow heat transfer according to their needs.

Furthermore, given that the fuel cell conditioning circuit ? separate at the level of fluid with respect to the conditioning circuit of the battery and the braking resistor, there ? no contamination issues that could lead to wear and tear from chemical reactions in the lines.

Thanks to the combination of all elements together ? possible:

- use the heat from the fuel cell and/or the braking resistor to heat the vehicle cabin and/or the battery module; And

- use the heat exchangers of the battery module and/or the brake resistor/cab heater as additional heat exchangers to cool the fuel cell and/or the brake resistor (and also the battery module if necessary ).

In the light of the foregoing, can be sufficient to use radiators (i.e. passive heat exchangers) instead of using coolers which require active conditioning means, except in exceptional circumstances.

As a result, not only the heat management system ? compact and requires fewer elements, being cos? less expensive, but also allows you to reduce energy consumption on the vehicle.

? It is clear that modifications can be made to the heat management system described for a fuel cell vehicle which do not extend beyond the scope defined by the claims.

For example, the relative topology of piping, valve and pumping means can be varied according to the type and size of the vehicle elements.

Furthermore, the heat exchanger and the pumping means, as well as like the temperature sensing means, they can be of any type.

Claims (15)

A vehicle comprising a fuel cell module (2), a battery module (3), a braking resistor means (4) and a cabin heater (5), said vehicle further comprising a heat management system ( 1) configured to fluidly connect together said fuel cell module (4), said battery module (3), said braking resistor means (4), said cabin heater (5) to a plurality of of heat exchangers (6, 7, 8) and at least one expansion tank (9) through a plurality? of ducts and valve means for allowing heat transfer between said fuel cell module (4), said battery module (3), said braking resistor means (4) and said cabin heater (5) in operation their temperature and their operating status. Vehicle according to claim 1, comprising: - a fuel cell portion (1') comprising said fuel cell module (2) and a fuel cell heat exchanger (6') connected at fluid level in series with respect to each other via a pair of ducts (11, 12), - a battery portion (1'') comprising said battery module (3) and at least one heat exchanger (6'', 7) connected at fluid level in series to each other via a pair of pipes ( 21, 22), - a braking resistor portion (1''') comprising said braking resistor means (4), a heat exchanger (8) and a cabin heater (5) connected at fluid level in series to each other the other via a pair of ducts (31, 32); wherein a conditioning fluid flowing in said fuel cell portion (1')? different with respect to a conditioning fluid flowing in said battery portion (1'') or said braking resistor portion (1'''). The heat management system according to claim 2, wherein a conditioning fluid flowing in said coil portion (1'') is the same conditioning fluid flowing in said braking resistor portion (1'''). The heat management system according to claim 2 or 3, wherein said heat exchanger (8) is a fluid-to-fluid heat exchanger which keeps said conditioning fluids of said fuel cell portion (1') separated at a fluid level with respect to said battery portion (1'') or said braking resistor portion (1 '''). 5. Heat management system according to any one of claims 2 to 4, wherein said fuel cell portion (1') comprises a bypass duct (13) interposed at fluid level in parallel with said pair of ducts (11, 12) for bypassing said fuel cell heat exchanger (6'), said bypass conduit (13) being connected at fluid level to at least one of said pair of conduits (11, 12) via valve means (14). The heat management system according to any one of claims 2 to 5, wherein said fuel cell portion (1') comprises pumping means (15) configured to circulate the conditioning fluid between said fuel cell module fuel (2) and said fuel cell heat exchanger (6'). A heat management system according to any one of claims 2 to 6, wherein said braking resistor portion (1''') comprises pumping means (33) configured to circulate the conditioning fuel between said heating means braking resistor (4), said cabin heater (5) and said heat exchanger (8). The heat management system according to any one of claims 2 to 7, wherein said coil portion (1'') comprises a first heat exchanger (6'') interposed at fluid level in series with said heating module coil (3) and a second heat exchanger (7) interposed at fluid level on a bypass duct (23) which connects at fluid level said pair of ducts (21, 22) in parallel to said first heat exchanger ( 6''), said bypass duct (23) being connected at fluid level to at least one of said pair of ducts (21, 22) via valve means (24). The heat management system according to any one of claims 2 to 8, wherein said battery portion (1'') comprises pumping means (25) configured to circulate conditioning fuel between said battery module (3 ) and said at least one heat exchanger (6'', 7). The heat management system according to claim 8, wherein said first heat exchanger (6'') is a radiator while said second heat exchanger (7) ? a cooler. 11. Heat management system according to any one of claims 2 to 10, wherein said two ducts (31, 32) of said braking resistor portion (1''') are each provided with valve means (31' , 31'') configured to allow or prevent the passage of fluid on the respective conduit (31, 32). The heat management system according to any one of claims 2 to 11 further comprising the following connecting ducts: - a first connection duct (41) configured to connect at fluid level a point on the second duct (32) of the braking resistor portion (1''') to the second duct (22) of the battery portion (1'' ) by valve means (41'); - a second connection duct (42) configured to connect at fluid level a point on the first connection duct (41) to the first duct (21) of the battery portion (1'') via valve means (42') and to a point on the second duct (32) of the braking resistor portion (1'''); - a third connection duct (43) configured to connect at fluid level a point on the second duct (32) of the braking resistor portion (1''') to the first duct (21) of the battery portion (1'' ); - a fourth connection duct (44) configured to connect at fluid level a point on the first duct (31) of the braking resistor portion (1''') to the second duct (22) of the battery portion (1'' ) at a point interposed at the fluid level between the battery radiator (6'') and the bypass duct (23), preferably via valve means (44'). The heat management system according to claim 12, wherein said first, said second and said third connecting ducts (41, 42, 43) are provided with valve means (41'', 42'', 43') configured to allow or prevent the passage of fluid on the respective conduit (31, 32). The heat management system according to claims 2 to 13, wherein at least one of said fuel cell portion (1'), said battery portion (1'') and said braking resistor portion (1' '') comprises an expansion tank (9', 9'', 9''') connected at fluid level to one of said pair of pipes (11, 12, 21, 22, 31, 32). A heat management system according to any one of said preceding claims, comprising sensor means configured to retrieve data related to the temperature of said fuel cell module (4), said battery module (3), said braking resistor means (4) and said cabin heater (5) is a unit? electronic control means electrically connected to said sensing means and including processing means for subsequently controlling said valve means and said pumping means as a function of data retrieved from said sensing means.