Heat-exchanger coil assembly

Abstract: The present invention provides a heat-exchanger coil assembly having increased heat conduction area for a given volume by reducing the centre spacing between heat-exchanger coils to a minimum level by avoiding a welding space. The heat-exchanger coil assembly comprises an inlet header (2) at an end section thereof, an inlet tube (3) for introducing a heat-exchanger medium, an outlet header (4) spaced from the inlet header at an end section of an outlet tube (5), and a plurality of heat-exchanger coils (8-1, 8-2, 8-3, 8-4 and 8-5) which are alternately linked to opposite sides of the inlet header (2) and outlet header (4). In another embodiment, the coils are alternately linked to two headers provided from a common inlet or outlet tube.

Description: The present invention relates to a heat-exchanger coil assembly, and more particularly to a heat-exchanger coil assembly for exchanging heat between a heat-exchanger medium accommodated in a housing or drum of a heat exchanger and a heat-exchanger medium flowing in the coil. An example of such a heat exchanger can be found in US Patent No. 4,256,176. The inventor for the present invention has already proposed, as disclosed in Japanese Patent Laid-Open Publication No.8 - 54192, a heat-exchanger coil assembly in which a plurality of heat-exchanger coils each having a different winding diameter are arranged so that they have a common centre line. With this heat-exchanger coil assembly, there are provided the advantages that the heat-exchanger efficiency can be improved without making larger a drum capacity of the heat-exchanger, and that the heat-exchanger capability can be freely set. In this type of heat-exchanger coil assembly, for example, as shown in Fig. 19, both ends of each of the heat-exchanger coils 28-1, 28-2, 28-3, 28-4 and 28-5 are linked to an inlet header and an outlet header respectively. The connection is achieved by welding the heat-exchanger coils 28-1, 28-2, 28-3, 28-4 and 28-5 to the same side of the inlet header and outlet header. Because of this configuration, a centre separation P' between any adjacent heat-exchanger coils 28-1, 28-2, 28-3, 28-4 and 28-5 must be set to at least a value obtained by adding a width 2α of a welding space to the external diameter d of the heat-exchanger coils 28-1, 28-2, 28-3, 28-4 and 28-5, and this required configuration disadvantageously makes it difficult to realize a small-sized and compact heat-exchanger coil assembly. The present invention was made to solve the problems associated with the conventional type of heat-exchanger coil assembly described above. The present invention provides a heat-exchanger coil assembly comprising: an inlet tube and an inlet header for introducing a heat-exchanger medium; an outlet tube and an outlet header for discharging a heat-exchanger medium; and a plurality of heat-exchanger coils each communicating the inlet header to the outlet header and having a different winding diameter; wherein the heat-exchanger coils have a common centre line, characterised in that the heat exchanger coils are alternately linked to opposite sides of the centre lines of the headers and in that the centre spacing P between two adjacent heat-exchanger coils, when viewed along the common centre line of the heat exchanger coils is equal to an outer diameter d of each of the heat exchanger coils. In one preferred embodiment, the inlet headers and outlet headers are located on opposite sides of a common centre line of the heat-exchanger coils. In another preferred embodiment, the inlet headers and outlet headers are located to one side of the common centre line of the heat-exchanger coils. In yet another preferred embodiment, a plurality of inlet headers and a plurality of outlet headers are linked to one inlet tube and one outlet tube respectively and the respective inlet headers and outlet headers are linked to each other with a heat-exchanger coil. In yet a further preferred embodiment, the inlet tube and outlet tube comprises first and second inlet tubes and first and second outlet tubes respectively, tips of the inlet headers of the first and second inlet tubes are non-communicably jointed to each other, tips of the outlet headers of the first and second outlet tubes are non-communicably jointed to each other, and also that heat-exchanger coil groups are arranged between the inlet header of the first inlet tube and the outlet header of the first outlet tube and between the inlet header of the second inlet tube and the outlet header of the second outlet tube respectively. Thus, in one preferred embodiment the inlet tube is provided with a first inlet header and a second inlet header and the outlet tube is provided with a first outlet header and a second outlet header. A first group of heat-exchanger coils are arranged between the first inlet header and the first outlet header, and a second group of heat-exchanger coils are arranged between the second inlet header and the second outlet header. In one such embodiment, the first group of heat-exchanger coils is different from the second group of heat-exchanger coils in terms of the coil length and coil diameter. In one preferred embodiment the heat-exchanger coils are linked to the first and second inlet headers alternately, and are also linked to the first and second outlet headers alternately. In another preferred embodiment, tips of the first and second inlet headers of the first inlet tube are non-communicably jointed to the first and second inlet headers of the second inlet tube, tips of the first and second outlet-headers of the first outlet tube are non-communicably linked to tips of the first and second outlet headers of the second outlet tube, and also that heat-exchanger coil groups are arranged between the first and second inlet headers of the first inlet tube and first and second outlet headers of the first outlet tube and between the first and second inlet headers of the second inlet tube and the first and second outlet headers of the second outlet tube respectively. In yet another preferred embodiment, a group of heat-exchanger coils corresponding to the first inlet tube and first outlet tube and a group of heat-exchanger coils corresponding to the second inlet tube and second outlet tube are different from each other in terms of the coil length and coil diameter. Preferably that the heat-exchanger coils have the same length. Certain preferred embodiments will now be described in greater detail by way of example only and with reference to the accompanying drawings, in which: Fig. 1 is a front view showing a first embodiment of the present invention; Fig. 2 is a view from above showing the same; Fig. 3 is a view showing a portion of the first embodiment cut along the line 3-3 in Fig. 1 and viewed from a direction indicated by the arrow in Fig. 1; Fig. 4 shows a second embodiment of the present invention; Fig. 5 shows a third embodiment of the present invention; Fig. 6 shows a fourth embodiment of the present invention; Fig. 7 is a front view showing a fifth embodiment of the present invention; Fig. 8 is a view from above showing the same; Fig. 9 is a front view showing a sixth embodiment of the present invention; Fig. 10 is a view from above showing the same; Fig. 11 is a front view showing a seventh embodiment of the present invention; Fig. 12 is a front view showing an eighth embodiment of the present invention; Fig. 13 is a view from above showing the same; Fig. 14 is a front view showing a linking section of a header of the same; Fig. 15 is a view showing a section through a ninth embodiment of the present invention; Fig. 16 is a view from above showing the same; Fig. 17 is a vertical cross-sectional view showing a heat-exchanger in which a preferred heat-exchanger coil assembly according to the present invention is applied; Fig. 18 is a lateral cross-sectional view showing the same; and Fig. 19 is an enlargement of a portion of a linking section of a header in a heat-exchanger coil assembly similar to that according to the present invention but based on the conventional technology. In a first embodiment of the present invention shown in Figs. 1 to 3, the reference numeral 1 indicates a heat-exchanger coil assembly 1, and in this heat-exchanger coil assembly 1, an inlet header 2 is provided at a lower and of an inlet tube 3 in a posture substantially perpendicular there-to and an outlet header 4 is provided at a lower end of an outlet tube 5 in a posture substantially perpendicular thereto. The inlet tube 3 and outlet tube 5 are located parallel to each other, and the inlet header 2 and outlet header 4 are located with a space therebetween having a centre line C-C, between the inlet tube 3 and outlet tube 5. A plurality of outflow ports 6-1, 6-3, 6-5 and 6-2, 6-4 (five holes in this embodiment) are provided in the peripheral wall of the inlet header 2 on both sides of the centre line B-B thereof with a specified centre spacing. The outflow ports 6-1, 6-3, 6-5 each having an odd number are located on one side of the centre line B-B of the inlet header 2, and the outflow ports 6-2, 6-4 each having an even number are located on the other side of the centre line B-B. Similarly, inflow ports 7-1, 7-3, 7-5 are located on one side of the centre line B'-B' of the outlet header 4 and inflow ports 7-2, 7-4 are located on the other side of the centre line B'-B'. A heat-exchanger coil group 8 comprising a plurality of heat-exchanger coils 8-1, 8-2, 8-3, 8-4, 8-5 (five heat-exchanger coils in this embodiment) are located between the inlet header 2 and the outlet header 4. Each of the heat-exchanger coils 8-1, 8-2, 8-3, 8-4, 8-5 has a different winding diameter and a common centre line C-C, and is formed by winding a tube around a heat conducting pipe made from such a material as a copper tube, a steel tube, a specific steel tube or the like in the conventional technology. Of the heat-exchanger coils constituting the group 8, both ends of each of the heat-exchanger coils 8-1, 8-3, 8-5 having an odd number respectively are linked to the outflow ports 6-1, 6-3, 6-5 each having an odd number of the inlet header 2 as well as to the inflow ports 7-1, 7-3, 7-5, the inflow ports 7-1, 7-3, 7-5 each having an odd number in the outlet header 4 respectively. Both ends of heat-exchanger coils 8-2, 8-4 each having an even number are linked to the outflow ports 6-2, 6-4 each having an even number in the inlet header 2 as well as to the inflow ports 7-2, 7-4 each having an even number in the outlet header 4 respectively. As described above, the ends of each of the heat-exchanger coils 8-1, 8-3, 8-5 and 8-2, 8-4 are alternately linked to opposite sides of the inlet header 2, i.e., either side of the centre line B-B of the inlet header 2, as well as opposite sides of the outlet header 4, and because of this configuration, a fluid flowing out from the inlet header 2 through one of the odd numbered heat-exchanger coils 8-1, 8-3, 8-5, flows in a direction opposite to fluid flowing through one of the even numbered heat-exchanger coils 8-2, 8-4. The heat-exchanger coil assembly 1 as described above is installed inside a housing or drum section 22 in which a second heat-exchanger medium 27 comprising a gas or a liquid for a heat-exchanger 21 as shown in Fig. 17 and Fig. 18 described below is accommodated. A first heat-exchanger medium comprising a gas or a liquid for exchanging heat with the second heat-exchanger medium 27 is introduced as a descending flow through the inlet tube 3 into a drum section 22. In this step, the first heat-exchanger medium flows through the outflow ports 6-1, 6-2, 6-3, 6-4, 6-5 in the inlet header 2, into the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5, and flows upward in a spiral form in these heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5. The first heat-exchanger medium exchanges heat with the second heat-exchanger medium in the drum section 22 via the walls of the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5 as it flows through the coils from the inflow ports 7-1, 7-2, 7-3, 7-4 and 7-5 into the outlet header 4, before being discharged through the outlet tube 5 from the drum 22 and sent to a load. With the heat-exchanger coil assembly 1 as described above, in which the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5 are adjacent to each other in the winding section, and of the outflow ports 6-1, 6-2, 6-3, 6-4, 6-5 and inflow ports 7-1, 7-2, 7-3, 7-4, 7-5, those having an odd number and those having an even number are located on opposite sides of the centre line B-B and B'-B' of the inlet header 2 and outlet header 4 respectively, so that the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5 which are adjacent to each other in the winding section are separated from each other in these linking sections. Because of this configuration, as shown in Fig. 3, which is different from a heat-exchanger coil assembly based on the conventional technology, an additional space for welding 2a is not required, and a centre spacing (i.e., when viewed from above) between two adjacent heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5 can be made equal to an outer diameter d of each of the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5. In this embodiment, there are five heat-exchanger coils 8, but the configuration is not limited to this, and the heat-exchanger efficiency can be freely set by selecting a different number of heat-exchanger coils according to the necessity, which makes it possible for the heat-exchanger coil assemblies to be useable in a range of heat-exchangers having various sizes from a small scale up to a large scale. Fig. 4, Fig. 5, and Fig. 6 show outlines of second, third, and fourth embodiments of the present invention. In the second embodiment shown in Fig. 4, the inlet tube 3 is located outside of the heat-exchanger coil group 8 (on the outer side of a coil having the maximum winding diameter), and the outlet tube 5 is located inside the heat-exchanger coil group 8 (on the inner side of a coil having the minimum winding diameter). In the third embodiment shown in Fig. 5, the inlet tube 3 is located inside the heat-exchanger coil group 8. In the fourth embodiment shown in Fig. 6, the inlet tube 3 and outlet tube 5 are located outside the heat-exchanger coil group 8. As described above, the inlet tube 3 and outlet tube 5 are located in various modes. These embodiments are different from the first embodiment only in the points described above, so that detailed description thereof is omitted herein. Fig. 7 and Fig. 8 show a fifth embodiment of the present invention, and this embodiment is different from the first to fourth embodiments in the point that both the inlet header 2 and outlet header 4 are located to one side of the centre line C-C of the heat-exchanger coil group 8. Because of the arrangement described above, the number of turns for each coil of the heat-exchanger coil group 8 is n, where n is an integer. A number of turns in a heat-exchanger coil group in the first to fourth embodiments of the present invention is n + 0.5, while that in the fifth embodiment is n, which saves a material for the heat-exchanger coil, and fifth embodiment is different from the first to fourth embodiments also in this point, but is the same as the first to fourth embodiment in other points, so that detailed description thereof is omitted herein. Fig. 9 and Fig. 10 each show a sixth embodiment of the present invention, and in this embodiment, first and second headers 2-1, 2-2 are provided in parallel to each other from the inlet tube 3, the outflow ports 6-1, 6-3, 6-5 each having an odd number are provided in the first inlet header 2-1 and the outflow ports 6-2, 6-4 each having an even number are provided in the second inlet header 2-2. Similarly, first and second outlet headers 4-1, 4-2 are provided in parallel to each other from the outlet tube 5, and the inflow ports each having an odd number are provided in the first outlet header 4-1, while the inflow ports each having an even number are provided in the second outlet header 4-2. Of the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5, both ends of the heat-exchanger coils 8-1, 8-3 and 8-5 each having an odd number are linked to the outflow ports 6-1, 6-3, 6-5 each having an odd number in the first inlet header 2-1 as well as to the inflow ports 7-1, 7-3, 7-5 each having an odd number in the first outlet header 4-1 respectively, and both ends of the heat-exchanger coils 8-2, 8-4 each having an even number are linked to the outflow ports 6-2, 6-4 each having an even number of the second inlet header 2-2 and to the inflow ports 7-2, 7-4 of the second outlet header 4-2 respectively. As the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5 are linked to the first and second inlet headers 2-1, 2-2 as well as to the first and second outlet headers 4-1 and 4-2 as described above, a flowing direction of a fluid in the heat-exchanger coils 8-1, 8-2, 8-3, 8-4, 8-5, may be the same as that in the first to fourth embodiments, but a centre spacing P between each of the heat-exchanger coils 8-1, 8-2, 8-3, 8-4, 8-5 in a linking section of the first and second inlet headers 2-1, 2-2 and the first and second outlet headers 4-1, 4-2 is the same as that in the first to fourth embodiments, and an additional space for welding 2α is not required to be provided, and the centre spacing P, when viewed from above, may be equal to an outer diameter d of each of the tubes forming the heat-exchanger coils 8-1, 8-2, 8-3, 8-4, and 8-5. Fig. 11 shows a seventh embodiment of the present invention, and this embodiment is the same as the sixth embodiment shown in Fig. 9 and Fig. 10 in the point that the first and second inlet headers 2-1, 2-2 are provided in the inlet tube 3, but is different from the sixth' embodiment in the point that the inlet headers 2-1, 2-2 and outlet headers 4-1, 4-2 are linked with different heat-exchanger coils 8-1, 8-2 respectively, and there is no different point other than that described above, and although there are shown only two pairs of inlet headers 2-1, 2-2 and outlet headers 4-1, 4-2 and two groups of heat-exchanger coils 8-1, 8-2, a larger number may be provided than in this embodiment. Fig. 12, 13, 14 each show an eighth embodiment of the present invention, and in this embodiment, end sections of the first inlet header 2-1 and second inlet header 2-2 and end sections of the first outlet header 4-1 and second outlet header 4-2 in the second embodiment shown in Fig. 4 as well as in the third embodiment shown in Fig. 5 are linked to each other and closed with linking plates 11 and 12, and further the first and second inlet tubes 3-1, 3-2 and first and second outlet tubes 5-1, 5-2 are provided therein. Because of the configuration as described above, the first inlet tube 3-1 and first outlet tube 5-1 are provided inside the second inlet tube 3-2 and second outlet tube 5-2, and the first inlet tube 3-1 and first outlet tube 5-1 may inlet or outlet a fluid for one load system X, while the second inlet tube 3-2 and second inlet tube 5-2 inlet and outlet a fluid for the other load system Y. In this embodiment, the heat-exchanger coils 8-1, 8-2, 8-3, 8-4, 8-5 communicated to the load system X and the heat-exchanger coils communicated to the load system Y may have either different or identical coil lengths or coil diameters respectively, and the coil length and coil diameter are decided according to calorie required in each of the load systems X and Y. Fig. 15 and Fig. 16 each show a ninth embodiment of the present invention, and in this embodiment, two sets of the heat-exchanger coil assembly according to the sixth embodiment shown in Fig, 9 are combined to respond to two load systems X and Y simultaneously. In this embodiment, there are provided the first and second inlet tubes 3-1, 3-2 and first and second outlet tubes 5-1, 5-2, and end sections of the first inlet headers 2-1, 2-2 and second inlet headers 2-3, 2-4 in the first and second inlet tubes 3-1, 3-2 and end sections of the first outlet headers 4-1, 4-2 and second outlet headers 4-3, 4-4 are linked to each other and closed with the linking plates 11, 12 respectively. Also in this embodiment, like in the eighth embodiment, a coil length and a coil diameter of each of the heat-exchanger coils 8-1, 8-2, 8-3, 8-4 and 8-5 communicated to the load system X may be either equal to or different from those of each of the heat-exchanger coils 8-6, 8-7, 8-8, 8-9, 8-10 communicated to the load system Y, and the factors are decided according to a calorie required in the load system X or Y. Fig. 17 and Fig. 18 each show a heat-exchanger 21 in which the heat-exchange coil assembly 1 according to the present invention is applied, and in this heat-exchanger 21, a furnace cylinder 23 is provided under a drum section 22 of this heat-exchanger 11, and a furnace chamber 24 is provided therein. A combustor 25 is installed in the furnace chamber 24, operations of this combustor are controlled by a thermostat, a gas in the furnace chamber 24 is heated by a flame generated therein, the heated gas heats water in the drum section 22 via tube walls of the convector tubes 28, 29 to a preset temperature, and then the gas is discharged through a discharge pipe 31 to outside. The drum section 22 is communicated via a conduit 32 to a water supply tank 33 with a ball tap 34 provided in the water supply tank 33, and water supply is performed via a water supply pipe so that a liquid surface of water reserved therein is kept at a constant level. A gas chamber 37 is formed above a liquid surface in the drum section 22, and a gas in this gas chamber 37 is released to atmosphere via a conduit 38, the water supply tank 33, and a release pipe 39. With this construction, the reserved water 27 is heated under a pressure lower than the atmospheric pressure, and also the temperature is kept below the boiling point (100°C). In this example, the heat-exchanger coil assembly 1 is connected to a load system such as a heating system, a hot-water supply unit, a bath, or a swimming pool not shown herein. Thus, at least in the illustrated embodiments, the present invention can be seen to provide a heat-exchanger coil assembly which minimises the centre spacing between adjoining heat-exchanger coil pipes by avoiding a welding space for linking an inlet header and an outlet header to the heat-exchanger coil, enabling the heat-exchanger assembly to be made smaller and installed within a space having limited room, while maintaining a large heat conducting area. The embodiments above were described only for understanding of the present invention, and the present invention is not limited to the embodiments, and various configurations are allowable in which, for instance, outlet tubes and inlet tubes are used in the reverse mode, a heating medium and a heat-receiving medium are used reversely, or a heat exchanger using the heat-exchange coil assembly therein is not of an upright type, but of a flat type.

Claims: A heat-exchanger coil assembly comprising: an inlet tube (3) and an inlet header (2) for introducing a heat-exchanger medium; an outlet tube (5) and an outlet header (4) for discharging a heat-exchanger medium; and a plurality of heat-exchanger coils (8) each communicating the inlet header to the outlet header and having a different winding diameter; wherein the heat-exchanger coils have a common centre line (C-C), characterised in that the heat exchanger coils are alternately linked to opposite sides of the centre lines (B-B, B'-B') of the headers (2,3) and in that the centre spacing P between two adjacent heat-exchanger coils, when viewed along the common centre line (C-C) of the heat exchanger coils is equal to an outer diameter d of each of the heat exchanger coils. The heat-exchanger coil assembly according to claim 1, wherein the inlet header (2) and the outlet header (4) are located on opposite sides of the common centre line (C-C) of the heat-exchanger coils (8). The heat-exchanger coil assembly according to claim 1, wherein the inlet header (2) and the outlet header (4) are located to one side of the common centre line (C-C) of the heat-exchanger coils (8). The heat-exchanger coil assembly according to claim 1, 2 or 3, wherein a plurality of inlet headers (2-1, 2-2) and a plurality of outlet headers (4-1, 4-2) are linked to one inlet tube (3) and to one outlet tube (5) respectively, and the inlet headers and outlet headers are linked to each other with the heat-exchanger coils (8) respectively. The heat-exchanger coil assembly according to claim 1, 2 or 3, wherein the inlet tube (3) and outlet tube (5) comprise first and second inlet tubes (3-1, 3-2) and first and second outlet tubes (5-1, 5-2) respectively; tips of inlet headers (2-1, 2-2) of the first and second. inlet tubes are non-communicably jointed to each other and also tips of outlet headers (4-1, 4-2) of the first and second outlet tubes are non-communicably jointed, and further heat-exchanger coil groups (8) are located between the inlet header of the first inlet tube and the outlet header of the first outlet tube and between the inlet header of the second inlet tube and the outlet header of the second outlet tube respectively. The heat-exchanger coil assembly according to claim 5, wherein a heat-exchanger coil group (8) for the first inlet tube (3-1) and first outlet tube (5-1) is different from a heat-exchanger coil group (8) for the second inlet tube (3-2) and second outlet tube (5-2) in terms of the coil length and coil diameter. The heat-exchanger coil assembly according to any of claims 4 to 6, wherein the heat-exchanger coils (8) are alternately linked to the first inlet header (2-1) and second inlet header (2-2) and also alternately linked to the first and second outlet headers (4-1, 4-2). The heat-exchanger coil assembly according to claim 7, wherein tips of the first and second inlet headers (2-1, 2-2) of the first inlet tube (3-1) are non-communicably jointed to the first and second inlet headers (2-1, 2-2) of the second inlet tube (3-2), tips of the first and second outlet headers (4-1, 4-2) of the first outlet tube (5-1) are non-communicably jointed to tips of the first and second outlet headers (4-1, 4-2) of the second outlet tube (5-2), and heat-exchanger coil groups (8) are located between the first and second inlet headers of the first inlet tube and the first and second outlet headers of the first outlet tube and between the first and second inlet headers of the second inlet tube and the first and second outlet headers of the second outlet tube respectively. The heat-exchanger coil assembly according to any preceding claim, wherein the heat-exchanger coils (8) have the same length.

Inventors: MARUYAMA NOBORU, MARUYAMA, NOBORU
Applicants: MARUYAMA NOBORU, MARUYAMA, NOBORU
Application year: 1999
Main classification: F28D7
IPC codes: F28D7