Patent Description:
As known, the temperature of some fluids circulating in a work vehicle, such as an agricultural vehicle, is controlled by means of a conditioning arrangement.

Usually, the conditioning arrangement includes a plurality of fluid circuits through which respective fluids, e.g. water, oil, organic gases, air, fuel and the like are circulated and each brought in thermal contact with another fluid, normally air drawn from the outside of the vehicle, to exchange heat with the latter. Examples are shown in <CIT> and <CIT>.

Typically, the heat exchanges take place within a plurality of radiators crossed by respective flows of ambient air.

In some agricultural vehicles, the radiators are provided at the front arranged in a series aligned according to the advancing direction of such agricultural vehicles.

Ahead of the series, a fan is arranged to generate a flow of fresh air through the radiators of the series, such that the fluids passing within the radiators may transfer heat to the flowing air.

To enhance the heat absorption capacity of the air flowing across the radiators, subcoolers are also provided in the spaces between the radiators, such that at least part of the heat absorbed by air is transferred to a subcooling fluid flowing in the subcoolers.

Although advantageous in terms of heat transfer performance, the presence of subcoolers renders the arrangement complex and expensive.

In the above context, the need is felt to simplify the conditioning arrangement without significantly decreasing the efficiency of the heat transfer from the fluids to the external air.

Another need that is felt is to downsize the radiators without losing transfer performance, in order to save weights and costs.

An object of the invention is to satisfy at least one of the above-mentioned needs, preferably in a simple and economic manner.

The object is reached by a conditioning arrangement and a related conditioning method as claimed in the appended set of claims.

Dependent claims set out particular embodiments of the invention.

For a better understanding of the present invention, preferred embodiments are described in the following, by way of non-limiting examples, with reference to the attached drawings wherein:.

In <FIG>, reference numeral <NUM> indicates a work vehicle, in particular an agricultural vehicle provided, as known, with an engine <NUM> carried by a chassis <NUM> and a conditioning arrangement <NUM> arranged in the space defined by such chassis <NUM> and specifically adapted to cool the engine <NUM>.

Vehicle <NUM> advances, in use, along to a direction A, according to which the chassis <NUM> defines a front portion <NUM>, an intermediate portion <NUM>, and a rear portion <NUM>.

In particular, the intermediate portion <NUM> defines a cab <NUM> for a vehicle driver, whereas the front portion <NUM> and the rear portion <NUM> carry respectively front wheels <NUM> and rear wheels <NUM> of vehicle <NUM>.

As usual, conditioning arrangement <NUM> define a plurality of circuits for respective first fluids and another circuit for a second fluid suitable for subtracting heat from the first fluids.

First fluids are brought in thermal contact with the second fluid to transfer heat thereto.

The circuit for the second fluid may be closed loop or an open circuit, as in the embodiments shown, which means that the second fluid is released in the environment after having absorbed heat from the first fluids and recharged from the environment as a fresh fluid charge.

In the specific case of the open circuit, the second fluid is the ambient air.

In the embodiments shown, the first fluids include a variety of distinct fluids, in particular a coolant for engine <NUM>, lubricating oil for transmissions, an organic gas for conditioning cab <NUM>, and compressed charge air for engine <NUM>. The coolant for engine <NUM> may be a liquid at room temperature and pressure, such as water.

<FIG> shows just a portion of each of the circuits for the first fluids at front portion <NUM> of vehicle <NUM>, in particular where the heat exchanges occur between the first fluids and the second fluid. Here, conditioning arrangement <NUM> comprises a plurality of heat exchangers such as radiators <NUM> respectively adapted to be fed internally with the first fluids and thus making part of the circuits for those first fluids.

Some of the latter circuits are closed loop circuits, specifically the ones for the coolant, the lubricating oil, and the organic gas; on the other hand, the circuit for the compressed charge air is clearly an open circuit.

Radiators <NUM> are arranged in a series along direction A, namely specifically aligned along a common longitudinal axis with direction A, and supported in a fixed position by chassis <NUM>, in particular front portion <NUM>, as shown.

Each of the radiators <NUM> defines an internal flow path for the corresponding first fluid to be conditioned therein. In the exemplarily embodiment of <FIG>, each radiator <NUM> comprises an inlet tank <NUM> provided with a corresponding inlet opening 16a, an outlet tank <NUM> provided with a corresponding outlet opening 17a, and a pipe bundle <NUM> that connects the inlet tank <NUM> with the outlet tank <NUM>.

More precisely, each inlet tank <NUM> is adapted to receive internally the corresponding first fluid fed through the relative inlet opening 16a and to distribute the received first fluid through the relative pipe bundle <NUM>. Each outlet tank <NUM> is adapted to collect the corresponding first fluid distributed through the relative pipe bundle <NUM>. The collected first fluid can be released through the corresponding outlet opening 17a.

Furthermore, in the same area of radiators <NUM>, conditioning arrangement <NUM> comprises a device, in particular a ventilation device <NUM>, e.g. a fan, to force the second fluid flowing through radiators <NUM>, in particular along direction A and, then, to be ejected by ventilation device <NUM> out of the vehicle <NUM>.

According to direction A, ventilation device <NUM> is placed ahead of the series of radiators <NUM>, i.e. behind the first radiator <NUM> of the series. Ventilation device <NUM> is supported by chassis <NUM>, in particular front portion <NUM> as shown.

Preferably, but not necessarily, the first radiator <NUM> is the one for the coolant; the second radiator <NUM> is the one for the lubricating oil; the third radiator <NUM> is the one for the charge air; lastly, the fourth radiator <NUM> is the one for the organic gas. The preferred order of the radiators <NUM> is due to the decreasing heat rejection of the first fluids according to direction A.

Before being supplied to the respective radiators <NUM>, the coolant and the lubricating oil have taken heat respectively from engine <NUM> and the transmissions of vehicle <NUM>; on the other hand, the organic gas and charge air have been heated by compression.

Ventilation device <NUM> forces the second conditioning fluid along direction A, such that the second fluid flows externally across pipe bundles <NUM> to come in thermal contact with the first fluids flowing internally through the same pipe bundles <NUM>.

Direction A defines a flow path for the second fluid, which is specifically rectilinear although it may be different according to obvious not shown embodiments.

Any two following radiators <NUM> in the series define a space <NUM> there between, in which the second fluid flows along direction A.

According to an aspect of the invention, conditioning arrangement <NUM> comprises pumping devices <NUM>, such as pumps or fans, to alter the amount of mass of the second fluid flowing in space <NUM>.

More precisely, in the embodiment of <FIG>, the amount of mass is altered by suction of a portion of the second fluid flowing in space <NUM>.

In particular, pumping devices <NUM> are configured to suck out a portion of the second fluid from space <NUM>, such that the flowing mass of heated second fluid due to the passage across one of radiators <NUM> is reduced.

More in particular, pumping devices <NUM> are placed within space <NUM> and discharge the sucked out second fluid into the environment. In the embodiment shown in <FIG>, pumping devices <NUM> are defined by a plurality of centrifugal fans.

Conditioning arrangement <NUM> further comprises a control unit <NUM>, which is connected to pumping devices <NUM> and to ventilation device <NUM>. Control unit <NUM> is configured to control pumping devices <NUM> and ventilation device <NUM> as well.

In detail, control unit <NUM> controls the amount of mass sucked out by each of the pumping devices <NUM> of the conditioning arrangement <NUM>. In other words, each pumping device <NUM> is controlled by control unit <NUM> in an independent manner with respect to the other pumping devices <NUM>.

Furthermore, control unit <NUM> controls ventilation device <NUM> to adjust the processed flow rate of the second fluid based on the amount of mass altered by pumping devices <NUM>.

In particular, for each operating pumping device <NUM>, the flow rate is accordingly adjusted such that the mass of second fluid forced along direction A is increased of the same amount of mass sucked out by that operating pumping device <NUM>.

In such a manner, the total amount of mass flowing along direction A is conserved over time. Hence, a portion of the heated second fluid is replaced by cooler second fluid, such that an overall decrease of temperature within space <NUM> occurs with a contextual increased heat absorption capacity of the flowing second fluid along direction A.

An example of the operation of conditioning arrangement <NUM> according to the above embodiment is now described hereinafter.

The first fluids carrying heat, in particular subtracted from components like engine <NUM> and transmissions of vehicle <NUM>, or produced during compression, is fed to inlet tanks <NUM> of the radiators <NUM> through inlet openings 16a. The first fluids flow through pipe bundles <NUM> and then leave the radiators <NUM> by the outlet openings 17a of the outlet tanks <NUM>.

At the same time, ventilation device <NUM> is operated together with one or more pumping devices <NUM>. Ventilation device <NUM> processes a flow rate that is equal for instance to a standard value stored in control unit <NUM> plus the total amount that will be sucked out by pumping devices <NUM>.

The second fluid progressively heats up by meeting radiators <NUM>, while accordingly the first fluids cool down on the other hand.

In <FIG>, reference numeral <NUM>' indicates a conditioning arrangement according to another embodiment of the invention.

Conditioning arrangement <NUM>' is similar to conditioning arrangement <NUM> and will be described hereinafter only as far as it differs therefrom; corresponding or equivalent parts of conditioning arrangements <NUM>, <NUM>' will be indicated where possible by the same reference numerals.

In particular, conditioning arrangement <NUM>' differs from conditioning arrangement <NUM> for the replacement of pumping devices <NUM> with pumping devices <NUM>', which are configured to take or admit further second fluid in space <NUM>, such that the flowing mass of fresh second fluid between radiators <NUM> is increased.

Pumping devices <NUM>' alter the amount of mass by intake of fresh second fluid in space <NUM>.

More in particular, pumping devices <NUM>' are placed within space <NUM> to charge the second fluid from the environment. In <FIG>, pumping devices <NUM>' are defined by a plurality of centrifugal fans.

Control unit <NUM> controls the amount of mass taken in by each of the pumping devices <NUM>'. Each pumping device <NUM>' is controlled in an independent manner with respect to the other pumping devices <NUM>'. Control unit <NUM> further controls ventilation device <NUM> to adjust the processed flow rate of the second fluid, in particular such that the mass of the second fluid forced along direction A is decreased of the same amount of mass taken in by each operating pumping device <NUM>'.

In such a manner, the total amount of mass flowing along direction A is conserved over time. Hence, the heated second fluid due to the passage through one of radiators <NUM> mixes with fresh second fluid, such that the overall temperature within space <NUM> is mitigated with a contextual increase of the heat absorption capacity of the flowing second fluid along direction A.

In this embodiment, ventilation device <NUM> may be downsized, as shown, since it should process a lower flow rate of second fluid.

The operation of conditioning arrangement <NUM>' is similar to that of conditioning arrangement <NUM> and is described only insofar as it differs therefrom.

In particular, the difference holds in that ventilation device <NUM> processes a flow rate that is equal for instance to the standard value minus the total amount that will be taken in by pumping devices <NUM>'.

In <FIG>, reference numeral <NUM>" indicates a conditioning arrangement according to a further embodiment of the invention.

Conditioning arrangement <NUM>" is similar to conditioning arrangement <NUM>' and will be described hereinafter only as far as it differs therefrom; corresponding or equivalent parts of conditioning arrangements <NUM>, <NUM>', and <NUM>'' will be indicated where possible by the same reference numerals.

In particular, conditioning arrangement <NUM>'' differs from conditioning arrangement <NUM>' as comprising a single pumping device <NUM>" instead of the plurality of pumping devices <NUM>'.

Pumping device <NUM>" is placed separately with respect to radiators <NUM>, i.e. in a space different from spaces <NUM>. However, pumping device <NUM>" can alter the amount of mass flowing in spaces <NUM> thanks to a plurality of ducts <NUM>" to bring respectively spaces <NUM> into communication with the space where pumping device <NUM>" is placed.

Pumping device <NUM>" is configured to displace an amount of second fluid through ducts <NUM>'', in particular from the space where it is placed to spaces <NUM>.

In the embodiment shown in <FIG>, each duct <NUM>'' comprises an annular-shaped or frame-shaped portion <NUM>'' surrounding a portion of a corresponding space <NUM> and provided with ports <NUM>" configured to be open, e.g. selectively, towards the surrounded space <NUM>. Portions <NUM>' are respectively arranged in the corresponding spaces <NUM>.

Moreover, each duct <NUM>'' is provided with a corresponding valve <NUM>'', e.g. an on-off valve or a control valve, to adjust the flow rate of the second fluid through the duct <NUM>'' so as to allow fluidic communication of the corresponding space <NUM> with pumping device <NUM>".

Control unit <NUM> is configured to control each valve <NUM>'' in an independent manner with respect to the other valves <NUM>''. Preferably, control unit <NUM> is also configured to control independently the opening of each of the ports <NUM>".

The operation of conditioning arrangement <NUM>'' is similar to that of conditioning arrangement <NUM>' and is described only insofar as it differs therefrom.

The second conditioning fluid pumped by pumping device <NUM>" splits into ducts <NUM>'' based on the position of valves <NUM>"; in case one of the valve <NUM>" is open, the second fluid circulates within the relevant portion <NUM>" and enters the corresponding space <NUM> to mix with the second fluid flowing along direction A.

In the following, a conditioning method using any one of the conditioning arrangements <NUM>, <NUM>', and <NUM>" will be described as comprising the following steps:.

In which the flow rate of the forced second fluid is adjusted based on the altered amount of mass.

Preferably, the alteration of the amount of mass may be performed by sucking out the second fluid or by admitting further second fluid between radiators <NUM>.

More preferably, the alterations between two different couples of radiators <NUM> are performed independently of each other.

In view of the foregoing, the advantages of the conditioning arrangements <NUM>, <NUM>', <NUM>", and of the method according to the invention are apparent.

Especially, the alteration of the mass flowing between radiators <NUM> and the relative compensation by adjusting the flow rate processed by ventilation device <NUM> provide for an overall reduction of the temperature of the flowing second fluid, such that the latter may absorb more heat from the first fluids.

In other words, the efficiency of the heat transfer is increased both in the case in which a portion of the second fluid is discharged in the environment from spaces <NUM>, as well in the case wherein fresh second fluid is admitted in spaces <NUM>.

Therefore, the presence of a subcooling circuit and of subcoolers as usual in the art is no longer needed and advantageously avoided, as in the embodiments shown.

Furthermore, radiators <NUM> may be downsized with cost, space, and weight savings.

It is clear that modifications can be made to the described conditioning arrangements <NUM>, <NUM>', <NUM>'' that do not extend beyond the scope of protection defined by the claims.

For example, the number of pumping devices <NUM>, <NUM>', and <NUM>" may be different with respect of that disclosed and illustrated in the drawings.

As well, the number of radiators <NUM> may be different. In particular, a fifth radiator <NUM> can be added, e.g. as the last of the series, for conditioning the fuel charge for engine <NUM>.

Direction A defines an external flow path that may have any shape, e.g. curvilinear, instead of rectilinear. Furthermore, direction A may be the opposite of the advancing direction of vehicle <NUM>.

Moreover, although the arrangements <NUM>, <NUM>', <NUM>" are described as provided for conditioning a plurality of distinct fluids, a modified arrangement according to the invention can be provided when the first fluids are actually separate portions of a single fluid, e.g. the coolant for engine <NUM>.

Claim 1:
A conditioning arrangement (<NUM>; <NUM>'; <NUM>") for a vehicle (<NUM>) comprising:
- a plurality of heat exchangers (<NUM>), including a first and a second heat exchanger, adapted to be fed with respective first fluids, and arranged in series along an external flow path (A) for a second fluid;
- fluid processing means (<NUM>) configured to force the second fluid flowing through the heat exchangers (<NUM>) along the external flow path, such that heat exchanges can occur between each of the first fluids and the second fluid;
- pumping means (<NUM>; <NUM>'; <NUM>", <NUM>") configured to alter the amount of mass of the second fluid flowing between the first and the second heat exchanger; and
- a control unit (<NUM>) configured to control said pumping means (<NUM>; <NUM>'; <NUM>'', <NUM>") to alter said amount of mass and said fluid processing means (<NUM>) configured to adjust the processed flow rate of the second fluid based on the altered amount of masswherein said pumping means (<NUM>; <NUM>') comprises at least a first pumping device arranged along the external flow path (A) between the first and the second heat exchanger, the conditioning arrangement is characterized in that the heat exchangers (<NUM>) include a third heat exchanger with the second heat exchanger arranged between the first and the third heat exchanger;
wherein said pumping means (<NUM>; <NUM>') comprises a second pumping device arranged along the external flow path between the second and the third heat exchanger;
the control unit (<NUM>) being configured to control the first pumping device in an independent manner with respect to the second pumping device.