Patent Description:
Heat pump systems are increasingly being used for air conditioning in electric vehicles. In terms of space requirements, one critical element is the inner condenser. <CIT> or <CIT> disclose heat exchangers according to the preamble of claim <NUM>.

The object of the invention is to provide as compact a solution as possible for an inner condenser for a heat pump HVAC system.

This object is achieved according to the invention by a heat exchanger comprising a first heat exchange row and a second heat exchange row overlapping with each other, wherein each heat exchange row comprises a first distributor and a second distributor and a plurality of parallel, coplanar tubes interconnecting the first distributor and the second distributor,.

Although this invention has been designed in particular for use with heat pump HVAC systems, it is evident how it may be applied more generally to double-row heat exchangers, in particular in cases where the heat exchanger needs to have a particularly compact structure.

Preferred embodiments of the invention are defined in the dependent claims, which are to be understood as an integral part of this description.

Further features and advantages of the invention will become clearer from the following detailed description of an embodiment of the invention, made with reference to the accompanying drawings, provided purely for illustrative and non-limiting purposes, in which:.

With reference to <FIG>, a heat exchanger is shown, indicated as a whole by reference sign <NUM>. In the example shown, the heat exchanger <NUM> is a heat transfer fluid/air heat exchanger, in particular an inner condenser of a heat pump HVAC system for an electric vehicle. An example of this system is shown in <FIG>. IC denotes an inner condenser with which a fan B is associated, which fan is provided for supplying heated air to the interior of the passenger compartment of the vehicle. C denotes a compressor for circulating the heat transfer fluid inside the circuit of the heat pump. EV denotes an expansion valve, and OC denotes an outer condenser provided to absorb energy from the outside air. Lastly, WHE denotes a recovery heat exchanger which is provided to recover waste heat from the electronic components and the battery of the vehicle.

With reference again to <FIG>, the heat exchanger <NUM> is a double-row heat exchanger; it therefore comprises a first heat exchange row <NUM> and a second heat exchange row <NUM> which overlap with each other. The overlapping relationship relates to the direction of the air which flows through the heat exchanger <NUM> and exchanges heat with the heat transfer fluid inside the heat exchanger <NUM>; this direction is orthogonal to the main faces of the heat exchanger <NUM>. The first heat exchange row <NUM> comprises a first distributor <NUM> and a second distributor <NUM> and a plurality of parallel, coplanar tubes <NUM> interconnecting the first distributor <NUM> and the second distributor <NUM>. Fins <NUM> are arranged between adjacent tubes <NUM>, which fins are not shown in detail. The second heat exchange row <NUM> comprises a first distributor <NUM> and a second distributor <NUM> and a plurality of parallel, coplanar tubes (not shown in the figures) interconnecting the first distributor <NUM> and the second distributor <NUM>. Fins are arranged between adjacent tubes, which fins are not visible in the figures. Two lateral plates <NUM> and <NUM> are fixedly connected to the opposite sides of the mass formed by the tubes <NUM> of the first heat exchange row <NUM> and by the tubes of the second heat exchange row <NUM>.

The aforementioned elements are joined to each other in a manner known per se, for example by means of braze-welding.

Each of the distributors <NUM>, <NUM>, <NUM>, <NUM> has a tubular body, for example having a circular cross section, on a lateral wall 11a, 12a, 21a, 22a of which a plurality of slots is formed, in each of which slots one end of a relevant tube <NUM> is inserted.

The first distributor <NUM> of the first heat exchange row <NUM> has an inlet I of the heat exchanger <NUM>. The second distributor <NUM> of the second heat exchange row <NUM> has an outlet OUT of the heat exchanger <NUM>. For convenience, hereinafter reference will only be made to this arrangement. However, the arrangement of the inlet and outlet may be different to that described herein.

The heat exchanger <NUM> also comprises a fluid connection element <NUM> which connects the first distributor <NUM> of the first heat exchange row <NUM> to the first distributor <NUM> of the second row <NUM>. For convenience, hereinafter reference will only be made to this arrangement. However, the arrangement of the fluid connection element may be different to that described herein.

A partition <NUM> is arranged within the first distributor <NUM> of the first heat exchange row <NUM>, which partition divides the first distributor <NUM> of the first heat exchange row <NUM> into an inlet chamber 11b and an outlet chamber 11c. For convenience, hereinafter reference will only be made to this arrangement. However, the arrangement of the partition may be different to that described herein, or the partition may even be absent.

The fluid connection element <NUM> connects the outlet chamber 11c of the first distributor <NUM> of the first heat exchange row <NUM> to the first distributor <NUM> of the second heat exchange row <NUM>. For convenience, hereinafter reference will only be made to this arrangement. However, the arrangement of the fluid connection element may be different to that described herein.

In the heat exchanger <NUM> described above, the heat transfer fluid follows a U-shaped path in the first heat exchange row <NUM>, by entering from the inlet IN of the first distributor <NUM> of the first heat exchange row <NUM> and flowing through the inlet chamber 11b of the first distributor <NUM> of the first heat exchange row <NUM>, the tubes <NUM> connected thereto, the second distributor <NUM> of the first heat exchange row <NUM>, and the tubes <NUM> which connect the second distributor <NUM> of the first heat exchange row <NUM> to the outlet chamber 11c of the first distributor <NUM> of the first heat exchange row <NUM>. The heat transfer fluid flows from the outlet chamber 11c of the first distributor <NUM> of the first heat exchange row <NUM>, through the fluid connection element <NUM>, to the first distributor <NUM> of the second heat exchange row <NUM>. The heat transfer fluid thus follows a single-pass path in the second heat exchange row <NUM>, by flowing through the first distributor <NUM> of the second heat exchange row <NUM>, the tubes of the second heat exchange row <NUM>, and the second distributor <NUM> of the second heat exchange row <NUM>, and finally exiting from the outlet OUT of the second distributor <NUM> of the second heat exchange row <NUM>.

With reference again to <FIG>, the fluid connection element <NUM> is a monolithic element which is made of metal material and fixed to the lateral walls 11a and 21a of the relevant first row distributor and second row distributor, which in the example shown are the first distributor <NUM> of the first heat exchange row <NUM> and the first distributor <NUM> of the second heat exchange row <NUM>. A plurality of conduits <NUM> is formed in the fluid connection element <NUM>, which conduits fluidically connect the first row distributor <NUM> and the second row distributor <NUM>.

The fluid connection element <NUM> is joined to the lateral walls 11a and 21a of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM> by means of material coupling, for example by means of braze-welding. For this purpose, the fluid connection element <NUM> comprises two junction surfaces <NUM> and <NUM> which correspond, respectively, to the lateral wall 11a of the first distributor <NUM> of the first heat exchange row <NUM> and to the lateral wall 21a of the first distributor <NUM> of the second heat exchange row <NUM>. The opposite ends of each of the conduits <NUM> lead, respectively, into one and the other of the junction surfaces <NUM> and <NUM>, and correspond to respective holes made in the lateral walls 11a and 21a of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>.

With reference to <FIG>, a further, not claimed heat exchanger is shown. Elements corresponding to those of the preceding example have been assigned the same reference signs; these elements will not be described again. In <FIG>, it is also possible to see the tubes of the second heat exchange row, which tubes are denoted by reference sign <NUM>.

The heat exchanger in <FIG> differs from that in <FIG> on account of the structure of the fluid connection element, which is now denoted by reference sign <NUM>' and is also shown in <FIG>.

The fluid connection element <NUM>' is a hollow monolithic block which is made of metal material and fixedly connected at the top to ends 11e and 12e, respectively, of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>. A conduit or cavity <NUM>' is formed in the fluid connection element <NUM>', which conduit or cavity fluidically connects the first distributor <NUM> of the first heat exchange row <NUM> to the first distributor <NUM> of the second heat exchange row <NUM>.

The fluid connection element <NUM>' is joined to the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM> by means of material coupling, for example by means of braze-welding. For this purpose, two openings or seats <NUM>' and <NUM>' are formed in the fluid connection element <NUM>' and connected to the conduit <NUM>', in which openings or seats the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM> are inserted, respectively. The conduit or cavity <NUM>' of the fluid connection element <NUM>' is also closed by a cover <NUM>' (shown in <FIG>).

With reference to <FIG>, a further, not claimed example is shown. Elements corresponding to those of the preceding examples have been assigned the same reference signs; these elements will not be described again. For simplicity, <FIG> shows only the detail of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>, which distributors are connected at the end to the fluid connection element, now denoted by <NUM>".

The fluid connection element <NUM>'' is a hollow monolithic plug which is made of metal material, is fork-shaped, and is inserted into the ends 11e and 12e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>. The fluid connection element <NUM>'' is joined to the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM> by means of material coupling, for example by means of braze-welding. A conduit or cavity (not shown in <FIG>) is formed in the fluid connection element <NUM>'', which conduit or cavity fluidically connects the first distributor <NUM> of the first heat exchange row <NUM> to the first distributor <NUM> of the second heat exchange row <NUM>. This conduit or cavity is closed, at the opposite end to the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first di stributor <NUM> of the second heat exchange row <NUM>, by a cover <NUM>".

With reference to <FIG>, an embodiment of the invention is shown. Elements corresponding to those of the preceding, not claimed examples have been assigned the same reference signs; these elements will not be described again. For simplicity, <FIG> shows only the detail of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>, which distributors are connected at the end to the fluid connection element, now denoted by <NUM>‴.

The fluid connection element <NUM>‴ is a hollow monolithic plug which is made of metal material, is fork-shaped, and is inserted into the ends 11e and 12e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>. The fluid connection element <NUM>‴ is joined to the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM> by means of material coupling, for example by means of braze-welding. A conduit or cavity <NUM>‴ is formed in the fluid connection element <NUM>‴, which conduit or cavity fluidically connects the first distributor <NUM> of the first heat exchange row <NUM> to the first distributor <NUM> of the second heat exchange row <NUM>. This conduit or cavity <NUM>‴ is closed, at the opposite end to the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>, by a cover <NUM>‴.

Respective notches 11n and 21n are formed on the lateral walls 11a and 21a of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>, at the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>, in which notches the fluid connection element <NUM>‴ is inserted. This arrangement makes it possible for an axial extension of the joint between the connection element and distributors to be smaller than the embodiment in <FIG> or even equal to zero in the event that the fluid connection element <NUM>‴ is completely inserted within the bulk of the distributors <NUM> and <NUM>, as in the example shown.

With reference to <FIG>, a further, not claimed example is shown. Elements corresponding to those of the preceding embodiments have been assigned the same reference signs; these elements will not be described again. For simplicity, <FIG> shows only the detail of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>, which distributors are connected at the end to the fluid connection element, now denoted by <NUM>"".

The fluid connection element <NUM>"" is an elbow tube which is made of metal material and has opposite ends inserted into the ends 11e and 12e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM>. The fluid connection element <NUM>"" is joined to the ends 11e and 21e of the first distributor <NUM> of the first heat exchange row <NUM> and of the first distributor <NUM> of the second heat exchange row <NUM> by means of material coupling, for example by means of braze-welding.

Claim 1:
A heat exchanger comprising a first heat exchange row (<NUM>) and a second heat exchange row (<NUM>) overlapping with each other, wherein each heat exchange row (<NUM>, <NUM>) comprises a first distributor (<NUM>, <NUM>) and a second distributor (<NUM>, <NUM>) and a plurality of parallel, coplanar tubes (<NUM>, <NUM>) interconnecting the first distributor (<NUM>, <NUM>) and the second distributor (<NUM>, <NUM>),
wherein each of said distributors (<NUM>, <NUM>, <NUM>, <NUM>) has a tubular body, on a lateral wall (11a, 21a, 12a, 22a) of which a plurality of slots is formed, in each of which slots one end of a relevant tube (<NUM>, <NUM>) is inserted,
wherein one of said first distributor and second distributor of the first heat exchange row has an inlet (IN) of the heat exchanger and one of said first distributor and second distributor of the second heat exchange row has an outlet (OUT) of the heat exchanger,
wherein the heat exchanger further comprises a fluid connection element (<NUM>"; <NUM>‴) connecting one of said first distributor and second distributor of the first heat exchange row, hereinafter referred to as the first row distributor (<NUM>), to one of said first distributor and second distributor of the second heat exchange row, hereinafter referred to as the second row distributor (<NUM>),
wherein said fluid connection element is an element (<NUM>"; <NUM>‴) which is fixedly connected at the top to ends (11e, 21e) of the first row distributor (<NUM>) and of the second row distributor (<NUM>) and in which a conduit (<NUM>‴) is formed that fluidically connects the first row distributor (<NUM>) to the second row distributor (<NUM>), wherein the fluid connection element (<NUM>"; <NUM>‴) is formed as a hollow plug inserted into the ends (11e, 21e) of the first row distributor (<NUM>) and of the second row distributor (<NUM>),
characterized in that respective notches (11n, 21n) are formed on the lateral walls (11a, 21a) of the first row distributor (<NUM>) and of the second row distributor (<NUM>), at the ends (11e, 21e) of the first row distributor (<NUM>) and of the second row distributor (<NUM>), in which notches the fluid connection element (<NUM>‴) is inserted.