EP1536198A1

EP1536198A1 - Heat exchanger

Info

Publication number: EP1536198A1
Application number: EP03425754A
Authority: EP
Inventors: Roberto Andreatta
Original assignee: Terra Energia Srl
Current assignee: Terra Energia Srl
Priority date: 2003-11-25
Filing date: 2003-11-25
Publication date: 2005-06-01

Abstract

Heat exchanger comprising a hollow body (1) which includes a first inlet chamber (4) from which a first bundle of tubes (5), which are arranged in a first exchange chamber (8) obtained in the hollow body (1) and lead into a first outlet chamber (6) arranged beside the first inlet chamber (4), departs, a first mobile wall (7) being arranged between the first inlet chamber (4) and the first outlet chamber (6) for mutually separating or connecting these two chambers (4, 6), wherein a second exchange chamber (13), which is adjacent to the first exchange chamber (8) and communicates with the latter, is obtained in the hollow body (1) so that a fluid can cross both exchange chambers (8, 13), that a plurality of hollow members (16) mutually connected by means of second tubes (17) is arranged in the second exchange chamber (13) for exchanging heat with said fluid, that these second tubes (17) are connected with a second inlet chamber (19) and a second outlet chamber (20) arranged beside the second inlet chamber (19), and that a second mobile wall (22; 26) is arranged between the second inlet chamber (19) and the second outlet chamber (20) for mutually separating or connecting these two second chambers (19, 20).

Description

The present invention relates to a heat exchanger, and in particular to a heat exchanger which can be employed in the cogeneration systems.
IT 1300455 discloses a heat exchanger for a cogeneration system, which includes a three-way valve obtained in the same hollow body of the heat exchanger, so as to reduce the structural complexity and the size of the whole system, with a consequent decrease of the manufacturing and maintenance costs.
However, in a cogeneration system some further devices are needed, such as cooling radiators, which keep the structural complexity and the size of the whole system relatively high.
It is therefore an object of the present invention to provide a heat exchanger which allows to avoid said drawbacks, i.e. a heat exchanger which can reduce the structural complexity and the size of a cogeneration system. Said object is achieved with a heat exchanger, the main features of which are disclosed in the first claim and other features are disclosed in the following claims.
Thanks to the second mobile walls and the second exchange, inlet and outlet chambers, all obtained in the hollow body which includes the first mobile wall and the first exchange, inlet and outlet chambers, the heat exchanger according to the present invention significantly reduces not only the structural complexity and the size of a cogeneration system, but also the relevant manufacturing and maintaining costs.
Furthermore, thanks to the particular circuit for the hot fluids and fluids to be heated, the heat exchanger according to the present invention allows to increase the thermal efficiency of the thermal exchange, i.e. the performance of the cogeneration system.
According to a particular aspect of the invention, the heat exchanger is provided with further mobile walls for circulating hot fluids between a motor and an external radiator, and vice versa, so as to increase the flexibility of the cogeneration system and consequently its uses.
Further advantages and features of the heat exchanger according to the present invention will become clear to those skilled in the art from the following detailed and non-limiting description of two embodiments thereof with reference to the attached drawings, wherein:

figure 1 shows a schematic side view in a longitudinal cross-section of the heat exchanger according to the first embodiment of the invention;
figure 2 shows a cross-sectioned view along plane II-II of the heat exchanger of figure 1;
figure 3 shows a cross-sectioned view along plane III-III of the heat exchanger of figure 1; and
figure 4 shows a schematic side view in a longitudinal cross-section of the heat exchanger according to the second embodiment of the invention.

Referring to figures 1 and 2, it is seen that the heat exchanger according to the first embodiment of the invention comprises in a known way an elongated hollow body 1, in particular having a substantially cylindrical shape, the inner cavity of which communicates with at least a first inlet duct 2 and a first outlet duct 3 for a hot fluid, in particular exhausted gases. The first inlet duct 2 leads into a first inlet chamber 4 obtained at an end of the hollow body 1, from which a bundle of first tubes 5 (figure 1 shows only one tube 5 for simplicity's sake), which are arranged in the hollow body 1 in a manner substantially parallel to the longitudinal axis of the latter, departs. The first tubes 5 are curved substantially at 180° so as to lead into a first outlet chamber 6 which is obtained in the hollow body 1 beside the first inlet chamber 4 and is connected to the first outlet duct 3. A first mobile wall 7, in particular having a substantially semicircular shape, is arranged between the first inlet chamber 4 and the first outlet chamber 6 for mutually separating or connecting these two chambers. The first mobile wall 7 can be rotated around an axis substantially perpendicular to the longitudinal axis of the hollow body 1, so as to be arranged against the inlet of the first tubes 5 for avoiding that the fluid coming from the first inlet chamber 4 passes through these tubes or to be arranged between the first chambers 4, 6 for forcing the same fluid to pass through the first tubes 5 before reaching the first outlet chamber 6 and the first outlet duct 3. The first mobile wall 7 with the first inlet and outlet chambers 4, 6 therefore form a three-way valve between the first inlet duct 2, the first outlet duct 3 and the first tubes 5.
The first tubes 5 are arranged in a portion 8 of the hollow body 1 which acts as a first exchange chamber and is adjacent to the first chambers 4, 6. A fluid, in particular water, to be heated with the heat of the fluid passing through the first tubes 5 can circulate in the first exchange chamber 8. For facilitating the thermal exchange, the first exchange chamber 8 is divided into more spaces by a plurality of transversal diaphragms 9 provided with openings 10 made at opposite positions with respect to the longitudinal axis of the hollow body 1. The first exchange chamber 8 is connected to a second outlet duct 11 and to a second inlet duct 12 for the fluid to be heated.
With reference also to figure 3, it is seen that, according to the invention, a second exchange chamber 13 which is adjacent to the first exchange chamber 8 and communicates with the latter, in particular through an opening 14 in a diaphragm 15 which separates chambers 8 and 13, is suitably obtained in the hollow body 1. The second inlet duct 12 leads into the second exchange chamber 13 so that the fluid to be heated crosses this chamber before passing into the first exchange chamber 8. A plurality of hollow members 16 mutually connected by means of second tubes 17 is arranged in the second exchange chamber 13 so that a hot fluid, in particular the cooling water of a motor, can exchange heat with the fluid to be heated. Said hollow members 16 are preferably made up of hollow plates arranged transversally with respect to the longitudinal axis of the hollow body 1.
Said hot fluid comes from a third inlet duct 18 which leads into a second exchange chamber 19 obtained at the opposite end of the hollow body 1 with respect to the one containing the first inlet and outlet chambers 4, 6. The second tubes 17, which are arranged in the hollow body 1 in a manner substantially parallel to the longitudinal axis of the latter, depart from the second inlet chamber 19. The second tubes 17 bring the hot fluid back into a second outlet chamber 20 which is obtained in the hollow body 1 beside the second inlet chamber 19 and is connected to a third outlet duct 21. A second mobile wall 22, in particular having a substantially semicircular shape, is arranged between the second inlet chamber 19 and the second outlet chamber 20 for mutually separating or connecting these chambers. The second mobile wall 22 can be rotated around an axis substantially perpendicular to the longitudinal axis of the hollow body 1, so as to close the inlet of the second tubes 17 and to deviate the fluid coming from the second inlet chamber 19 toward the second outlet chamber 20 or to be arranged between the second chambers 19 and 20 to force the same fluid to pass through the second tubes 17 before reaching the second outlet chamber and the third outlet duct 21. The second mobile wall 22 with the second inlet and outlet chambers 19, 20 therefore form a three-way valve between the third inlet duct 18, the third outlet duct 21 and the second tubes 17. Preferably, the second inlet duct 12 is arranged adjacent to the second chambers 19, 20, while the second outlet duct 11 is arranged adjacent to the first chambers 4, 6, or vice versa.
A third mobile wall 23, in particular having a substantially semicircular shape, can be arranged between the second tubes 17 and the second mobile wall 22 for deviating the fluid coming from the second inlet chamber 19 toward a fourth outlet duct 24, which can be connected in turn to an external device, in particular a radiator for cooling said fluid. A fourth inlet duct 25 leads into the second outlet chamber 20 for bringing this fluid back toward the third outlet duct 21.
Referring to figure 4, it is seen that the second embodiment of the invention differs from the first embodiment in that the second mobile wall 26 (or a further mobile wall) can separate the second tubes 17 from the second outlet chamber 20 and that the third mobile wall 27 (or a further mobile wall) is arranged between the second tubes 17 and the second outlet chamber 20 for deviating the fluid coming from the fourth inlet duct 25 toward the third outlet duct 21.
Further modifications and/or additions may be made by those skilled in the art to the embodiment of the invention hereinabove disclosed and illustrated while remaining within the scope of the same invention.

Claims

Heat exchanger comprising a hollow body (1) which includes a first inlet chamber (4) from which a first bundle of tubes (5), which are arranged in a first exchange chamber (8) obtained in the hollow body (1) and lead into a first outlet chamber (6) arranged beside the first inlet chamber (4), departs, a first mobile wall (7) being arranged between the first inlet chamber (4) and the first outlet chamber (6) for mutually separating or connecting these two chambers (4, 6), characterized in that a second exchange chamber (13), which is adjacent to the first exchange chamber (8) and communicates with the latter, is obtained in the hollow body (1) so that a fluid can cross both exchange chambers (8, 13), that a plurality of hollow members (16) mutually connected by means of second tubes (17) is arranged in the second exchange chamber (13) for exchanging heat with said fluid, that these second tubes (17) are connected with a second inlet chamber (19) and a second outlet chamber (20) arranged beside the second inlet chamber (19), and that a second mobile wall (22; 26) is arranged between the second inlet chamber (19) and the second outlet chamber (20) for mutually separating or connecting these two second chambers (19, 20).
Heat exchanger according to the previous claim, characterized in that said hollow members (16) are made up of hollow plates arranged transversally with respect to the longitudinal axis of the hollow body (1).
Heat exchanger according to one of the previous claims, characterized in that the first mobile wall (7) with the first inlet (4) and outlet (6) chambers form a three-way valve between a first inlet duct (2), a first outlet duct (3) and the first tubes (5).
Heat exchanger according to one of the previous claims, characterized in that a second inlet duct (12) for the fluid which crosses the two exchange chambers (8, 13) is arranged adjacent to the second inlet and outlet chambers (19, 20), while a second outlet duct (11) for the same fluid is arranged adjacent to the first inlet and outlet chambers (4, 6), or vice versa.
Heat exchanger according to one of the previous claims, characterized in that the second mobile wall (22; 26) with the second inlet (19) and outlet (20) chambers form a three-way valve between a third inlet duct (18), a third outlet duct (21) and the second tubes (17).
Heat exchanger according to one of the previous claims, characterized in that the first inlet chamber (4) and the first outlet chamber (6) are obtained at one end of the hollow body (1).
Heat exchanger according to one of the previous claims, characterized in that the second inlet chamber (19) and the second outlet chamber (20) are obtained at one end of the hollow body (1).
Heat exchanger according to one of the previous claims, characterized in that the first tubes (5) are curved substantially at 180° and are arranged in the hollow body (1) in a manner substantially parallel to the longitudinal axis of the latter.
Heat exchanger according to one of the previous claims, characterized in that a further mobile wall (23) is arranged between the second tubes (17) and the second mobile wall (22) for deviating the fluid coming from the second inlet chamber (19) toward a fourth outlet duct (24).
Heat exchanger according to one of the previous claims, characterized in that a further mobile wall (27) is arranged between the second tubes (17) and the second mobile wall (26) for deviating the fluid coming from a fourth inlet duct (25) toward the second outlet chamber (20).
Heat exchanger according to one of the previous claims, characterized in that one or more mobile walls (7, 22; 26, 23; 27) can be rotated around an axis substantially perpendicular to the longitudinal axis of the hollow body (1).
Heat exchanger according to one of the previous claims, characterized in that the hollow body (1) has a substantially cylindrical shape and one or more mobile walls (7, 22; 26, 23; 27) have a substantially semicircular shape.