EP0843134A1

EP0843134A1 - Heating apparatus with storage vessel and heat exchanger, and method for manufacturing same

Info

Publication number: EP0843134A1
Application number: EP97203608A
Authority: EP
Inventors: Jan Hubertus Deckers
Original assignee: Holding Jh Deckers Nv
Current assignee: Aluheat BV
Priority date: 1996-11-19
Filing date: 1997-11-19
Publication date: 1998-05-20
Anticipated expiration: 2017-11-19
Also published as: DE69719917D1; DE69719917T2; EP0843134B1; ATE235029T1; NL1004570C2

Abstract

Heating apparatus (1), comprising a storage vessel (2) and a heat exchanger (3) extending in the storage vessel (2), which heat exchanger (3) comprises a burner space (19) and, connecting thereto, a heat-exchanging part (21) and is provided with gas mixture-supply means for a gas-air mixture (16) to burner means (17) disposed in the burner space and flue gas-discharge means, wherein the storage vessel (2) comprises water-supply means (7) and water-discharge means (10), wherein the heat exchanger (3) is substantially manufactured through casting from light metal and the vessel is substantially manufactured from sheet material, wherein the gas mixture-supply means are disposed adjacent a first end (15) of the heat exchanger and the flue gas-discharge means are disposed adjacent a second end (23) spaced from the first end (15), wherein the first end of the heat exchanger (3) is located adjacent the top side of the storage vessel in a first wall part of the storage vessel (2) and the second end (23) is located adjacent a bottom side of the storage vessel (2) in a second sheet part, and wherein the storage vessel (2) is adapted for storing and feeding through water for use in a space-heating circuit (9).

Description

The invention relates to a heating apparatus according to the preamble of claim 1. Such heating apparatus is known from Dutch patent application 93 01274.

This known heating apparatus comprises a storage vessel manufactured from sheet steel, into which a heat exchanger cast from aluminum is inserted. The heat exchanger comprises a centrally disposed, cylindrical burner space with a water duct provided around it for the feed-through of water for use in a space-heating apparatus. On the side of the water duct remote from the burner space, a flue gas-discharge channel, disposed concentrically relative to the burner space, is cast integrally therewith, whose end face connects to the burner space and which has a discharge side that is annular around the end of the burner space extending outside the storage vessel. Hence, in this heat exchanger, the flow path for the flue gases of the burner comprises an angle of 180° at the end face of the burner space. During use, sanitary water is held in store in the storage vessel and heated up through heat exchange with the flue gases.

This known heating apparatus is relatively compact, while in particular the relatively high heat capacity of the aluminum heat exchanger is advantageous for obtaining a relatively high efficiency and a short convenience time. A drawback of this known heating apparatus, however, is that the heat exchanger used therein is relatively complicated and that it is less suitable for using the storage vessel for storing and feeding through water for use in a space-heating circuit (CH-water). This is in particular the result of the position of the water duct. The cylindrical wall of the burner space is screened thereby, so that no direct heat exchange can take place between the CH-water and the wall of the burner space.

The object of the invention is to provide a heating apparatus of the type described in the preamble of the main claim, wherein the drawbacks mentioned are avoided, while the advantages thereof are maintained. To that end, a heating apparatus according to the invention is characterized by the features of the characterizing part of claim 1.

By positioning the first and second ends of the heat exchanger at a distance from each other, with the heat exchanger extending between the two ends, an optimum contact surface between the heat exchanger and the water in the storage vessel is obtained, wherein the portion of the heat exchanger which during use is the hottest is located at the top of the storage vessel, which is energetically favorable, because the hot water in the storage vessel will rise and hence be collected at the top of the storage vessel, so that some stratification is created in the storage vessel and an optimum heat transfer is in each case provided. A heat exchanger for use in a heating apparatus according to the invention has a relatively simple construction and can easily be mounted in a storage vessel. By positioning the second end, which is the coldest during use, adjacent the bottom side of the storage vessel, the heating apparatus can be of condensing construction, while moreover, the condensate can easily flow from the heat exchanger or at least be removed therefrom. Moreover, the heat exchanger can be of a relatively slender design, so that a great freedom of design is obtained as far as the outside dimensions of the storage vessel are concerned.

The use of sheet steel for the vessel offers the advantage that such storage vessel is easy to construct, easy to insulate and moreover offers a great freedom of design. By having the heat exchanger extend between a first end and a second end spaced therefrom, the connection for the flue gas-discharge means and the gas mixture supply means can be constructed in a simple manner and, moreover, they can be arranged in a strategic position.

The heat exchanger is laid out in such a manner that the heat capacity of the aluminum in relation to the water volume is such that a bypass pipe is superfluous. In the storage vessel, natural circulation occurs; overheating of the water in the storage vessel is prevented in an advantageous manner.

A heat exchanger for use in a heating apparatus according to the invention can advantageously be of a one-piece design, which is energetically favorable and, moreover, is preferred in terms of production. Moreover, for casting the heat exchanger, only one core will suffice.

In a first advantageous embodiment, a heating apparatus according to the invention is further characterized by the features of claim 2.

Including at least one bend in the heat exchanger between the first and the second end offers the advantage that differences in expansion between the heat exchanger and the storage vessel can be taken up in a simple manner. This is in particular of importance as the aluminum of the heat exchanger will have a coefficient of expansion different from that of the sheet material of the storage vessel. Moreover, such embodiment offers the advantage that a heat exchanger of a relatively great length between the first and second ends can be incorporated into a relatively low storage vessel, while the height of the storage vessel is further independent of the height of the heat exchanger. This means that the same heat exchanger can readily be incorporated into storage vessels having different inside or outside dimensions, in particular height dimensions, while in particular above and/or below the heat exchanger relatively large or small spaces can be included. In such space, for instance further heat-exchanging elements may be accommodated.

Preferably, one bend is included in the heat exchanger. Such embodiment is particularly simple and offers the most freedom of design. The circumferential wall of the storage vessel is preferably at a relatively small distance from the outer side of the heat exchanger. Thus, a proper heat distribution and circulation and an optimum heat transfer is obtained during use.

In a first preferred embodiment, a heating apparatus according to the invention is characterized by the features of claim 3.

Connecting a first end of the heat exchanger to a cover and the second end to the wall or the other way round offers the advantage that the first and second sheet parts can deform relative to each other in a relatively simple manner, in particular when for instance at least one of the sheet parts is of a slightly convex or otherwise deformable construction. As a result, differences in expansion of the heat exchanger and the storage vessel can easily be taken up.

In a first further embodiment, a heating apparatus according to the invention is further characterized by the features of claim 6.

Positioning at least one tapping coil in the storage vessel, spaced from the heat exchanger, offers the advantage that the heat generated by the heat exchanger during use can also be used for heating water for use in an apparatus other than the space-heating apparatus connected between the water-supply means and water-discharge means. Such tapping coil can for instance be connected to a sanitary water apparatus, a floor-heating apparatus or another low-temperature heating apparatus. During use, water flowing through the or each relevant tapping coil can be heated through heat exchange with the water in the storage vessel which has been or is being heated through heat exchange with the heat exchanger.

In a further preferred embodiment, a heating apparatus according to the invention is further characterized by the features of claim 9.

Owing to the elements which increase the heat-transferring area, a large contact face between the water and the heat exchanger can, in the case of a relatively compact construction of the heat exchanger, nevertheless be obtained, so that during use, heat exchange between the flue gases and the water can take place with a high efficiency. Moreover, the elements which increase the heat-transferring area can be adapted for providing a specific flow of the water along the heat exchanger. By casting the elements integrally with the heat exchanger, it can be manufactured in a simple and relatively cheap manner while, moreover, no contact losses occur between interconnected parts.

The invention moreover relates to a method for manufacturing a heating apparatus according to the invention. To that end, a method according to the invention in a first embodiment is characterized by the features of claim 10.

In this method, the vessel may first be assembled for the greater part, after which the heat exchanger can be mounted in the vessel from an open side. Contiguously, the vessel can be closed so that the storage vessel is watertight and the heating apparatus can further be completed. Positioning the heat exchanger within the storage vessel via an open side enables simple assembly and sealing of the heat exchanger against the storage vessel.

In a further embodiment, a method according to the invention is characterized by the features of claim 11.

By attaching the heat exchanger to the relevant cover, while providing at least one tapping coil around at least a portion of the heat exchanger, the heat exchanger together with the or each relevant tapping coil can readily be slid into the vessel and secured therein. This readily enables manipulation and attachment of the assembly. By connecting the or each tapping coil to the relevant cover, the heat exchanger and the tapping coil can be mounted together, with the position of the heat exchanger relative to the or each relevant tapping coil being fixed. Such method enables manufacturing a heating apparatus according to the invention in a simple and relatively cheap manner.

In an alternative embodiment, a method according to the invention is characterized by the features of claim 12.

In this embodiment, a heat exchanger according to the invention can easily be mounted in a vessel already manufactured and closed. Via a first opening, the heat exchanger is introduced into the vessel and brought into the operating position through tilting, after which the heat exchanger is attached by the first and second ends thereof to the wall of the heat exchanger. As a matter of fact, a comparable method is possible when the heat exchanger is for instance substantially T-shaped, J-shaped or, for instance, Z-shaped. This merely involves the necessity of choosing the length of the different parts of the heat exchanger to be such that insertion and tilting of the heat exchanger within the closed vessel is possible. Next, attaching the first and second ends of the heat exchanger to the wall and/or a cover of the storage vessel is possible in a simple manner, for instance by means of appropriate flanges, packings and fastening bolts or the like. The invention further relates to a method for controlling the heat supply to a heating circuit during the use of a heating apparatus according to the invention. Such method is characterized by the features of claim 13.

By mixing relatively cold return water with relatively warm water from the storage vessel, depending on the heat demand and/or the water temperatures, the heat demand can always be satisfied in a suitable manner, without involving thermal shocks. Thermal shocks are undesired, as they may cause noise nuisance and damages to the apparatus and, possibly, the environment, and may moreover involve danger to humans and animals as a consequence of the rapid rise of temperature in the relevant heating circuit.

Further advantageous embodiments of a heating apparatus and methods according to the invention are given in the subclaims.

To clarify the invention, exemplary embodiments of an assembly and method will hereinafter be described, with reference to the accompanying drawings. In these drawings:

Fig. 1 is a sectional side elevation of a first embodiment of a heating apparatus according to the invention, with heating means schematically connected thereto;

Fig. 2 is a sectional side elevation of a second embodiment of a heating apparatus according to the invention, with heating means schematically connected thereto;

Fig. 3 is a sectional side elevation of a third embodiment of a heating apparatus according to the invention, with heating means schematically connected thereto;

Fig. 4 is a sectional side elevation of a fourth embodiment of a heating apparatus according to the invention, with heating means schematically connected thereto;

Figs. 4A and 4B schematically show heating circuits for use in a heating apparatus according to the invention; and

Fig. 5 is a sectional side elevation of a fifth embodiment of a heating apparatus according to the invention, with heating means schematically connected thereto.

The variants of a heating apparatus according to the invention that are shown in the drawings are all depicted schematically. In the drawings, identical parts are provided with corresponding reference numerals.

In this specification, 'light metal' should at least be understood to mean aluminum, aluminum alloys and like metals and metal alloys. As casting manners for the manufacture of a heat exchanger for use in a heating apparatus according to the invention, all types of suitable casting manners, known per se, can be applied.

Fig. 1 is a sectional side elevation of a heating apparatus 1, comprising a storage vessel 2 and a heat exchanger 3 which extends substantially within the storage vessel 2. The storage vessel 2 is preferably manufactured from sheet steel and is built up of a cylindrical longitudinal wall 4, a top cover 5 and a bottom cover 6. The covers 5, 6 can be connected to the longitudinal wall in different manners, for instance so as to be entirely or partially detachable, yet at least one cover is preferably fixedly connected to the longitudinal wall, for instance through welding. The storage vessel 2 has its outer side provided with insulation (not shown).

The storage vessel 2 is provided with water-supply connecting means 7 for connecting to a return pipe 8 of a space-heating circuit 9 (shown schematically) and with water-discharge connecting means 10 for connecting the supply pipe 11 of the space-heating circuit 9. The water-supply connecting means 7 terminate adjacent the bottom side, the water-discharge connecting means 10 terminate adjacent the top side of the storage vessel 2. Included in the space-heating circuit 9 is a pump 12 for pumping therein and through the storage vessel 2 water heated by means of the heat exchanger 3, to be described in more detail hereinbelow.

In the heating circuit 9, a controllable three-way valve 60 is included in the return pipe 8. This three-way valve is connected, via a connecting pipe 61, to the supply pipe 11. During use, the three-way valve 60 can be controlled by means of the motor 62 so that a mixture can be obtained of hot water from the storage vessel 2 and relatively cool water coming from the return pipe 8 of the heating circuit 9. Next, during use, this mixture of water having two different temperatures is passed to the radiators or the like in the heating circuit, via the supply pipe 11. Through a suitable choice of the mixing ratio, the passing of too hot water into the heating circuit 9 can be prevented. Thus, noise nuisance, expansion and shrinkage of the parts of the heating circuit and undue rises of temperature in the spaces are prevented. Moreover, this prevents the pipes and the heating bodies from heating up too quickly, which could cause humans and animals to scald themselves. A further advantage of the three-way valve is that the water in the storage vessel 2 can continuously be maintained at a high temperature while the temperature of the water passed to the heating circuit 9 can nevertheless always be set appropriately, for instance on the basis of the water temperatures measured in the storage vessel 2 and in the return pipe 8 and the heat demand in the spaces, at least in the relevant heating circuit. Thus, any heat demand can be satisfied in a quick and advantageous manner. The high temperature of the water in the storage vessel 2 moreover offers the advantage that the convenience time for a sanitary-water circuit which may be connected to the heating apparatus is short. The convenience time is the time between the occurrence of a heat demand and the fulfillment thereof.

The heat exchanger 3 is cast from light metal and is slightly T-shaped. The top, horizontal part 13 of the heat exchanger 3 comprises a burner space 14 and a first end 15 of the heat exchanger 3, fastened to the longitudinal wall 4 of the storage vessel 2 and covering a first opening 16. The burner space 14 has a polygonal cross section, with relatively large radii having been chosen for the faces because of pressures occurring and the necessary strength. Disposed in the burner space 14 is a burner 17 which comprises a cylindrical burner face 18 and extends approximately in the longitudinal direction of the horizontal part 13 of the heat exchanger 3, substantially throughout the length thereof. Connected to the first end 15 is a fan 26 for supplying a gas-air mixture to the burner 17.

Via a slightly conical part 19, the horizontal part 13 is connected to the vertical part 20 of the heat exchanger 3. The vertical part 20 comprises a heat-exchange part 21 provided on the inside with first elements 22 which increase the heat-transferring area, for instance cast-on projections or partitions. These first elements 22 are preferably constructed as rows of projections 22 which are slightly staggered relative to each other and which form meandering passages for flue gases, between the burner 17 and the second end 23 of the heat exchanger 3. The second end 23 of the heat exchanger 3 is connected to the bottom cover 6. To that end, there is provided in the bottom cover 6 a second opening 24, over which the second end 23 is connected in a covering manner. The second end 23 is suitable for the connection of flue gas-discharge means, such as a chimney. The first end 15 and the second end 23 are both connected to the longitudinal wall 4 and the bottom cover 6 respectively in such a manner that the storage vessel 2 is watertight, except for the water-supply and water-discharge means 7, 10 for the heating circuit 9 mentioned.

Provided on the outside of the heat exchanger 3, in particular on the vertical part 20 and at least at the level of the heat-exchanging part 21, are second elements 25 which increase the heat-transferring area, for instance cast-on projections or partitions. The projections or partitions 25 can have any suitable shape, for instance annularly extending, ring-shaped partitions, partitions extending in longitudinal direction of the vertical part 20 or rows and columns of projections. Also, one or more spirally extending partitions can be applied, so that, during use, a flow of water along the partitions and, accordingly, along at least the heat-exchanging part 21 of the heat exchanger 3 is stimulated without necessitating moving parts. As a result, during use, the heat transfer between flue gases in the heat exchanger and water in the storage vessel can be improved still further.

A heating apparatus 1 according to Fig. 1 can be built up as follows. The longitudinal wall 4 of the storage vessel 2 is manufactured for instance from sheet by rolling and welding up the seam. Next, the covers 5, 6 are manufactured, preferably so as to be slightly convex. In the longitudinal wall 4 and the bottom cover 6, the first 16 and second opening 24 respectively are provided. The heat exchanger 3 is cast and subsequently brought within the longitudinal wall 4, after which, preferably with the interposition of a suitable packing, O-rings or the like, the first end 15 of the heat exchanger 3 is secured to the longitudinal wall. Contiguously, the bottom cover 6 is secured to the longitudinal wall, while the second end 23 is secured over the second opening 24, again preferably with the interposition of a suitable packing or the like. For that purpose, the heat exchanger 3 has its two ends provided with suitable flanges which can be secured to the longitudinal wall 4 by means of, for instance, bolts, preferably from the outside. Finally, the top cover 5 is secured on the longitudinal wall 4. Because the storage vessel 2 is not closed and welded up until the heat exchanger 3 and other assembly parts, if any, have been installed, i.e. until the heating apparatus has been further completed, tolerance problems, for instance caused by manufacturing, axial tensions and the like, are prevented from adversely affecting the heating apparatus, in particular the watertightness and safety thereof.

Of course, such heating apparatus can also be built up in a different manner, for instance by a different order of assembly. For instance, the heat exchanger can be mounted on the bottom cover 6 and then be inserted into the storage vessel 2 for being contiguously attached to the longitudinal wall 4. This prevents the heat exchanger 3 from suspending from the first end 15 of the horizontal part 13 during assembly, which can be unfavorable in terms of loading, in particular if a relatively heavy, long heat exchanger 3 is involved. Also, the bottom cover 6 may be fixed first, after which the heat exchanger is inserted into the storage vessel from the top side and is fixed to the bottom cover 6 and the longitudinal wall 4. Such assembly may be favorable in terms of loading, yet is inconvenient in the case of a relatively high, narrow storage vessel, because of the maneuvering space available. In this manner, many variations are possible.

Because the first end is secured in or at least to the longitudinal wall 4 and the second end 23 is secured in the bottom cover 6, differences in the coefficients of expansion of the storage vessel 2 and the heat exchanger 3 can readily be taken up, in particular when the bottom cover 6 is of a slightly convex and relatively flexible construction. The bottom cover 6 can act as expansion spring and readily take up deformations due to expansion and shrinkage. The same heat exchanger 3 can be utilized in storage vessels 2 of different heights and/or diameters, because the first opening 16 and the second opening 24 can in each case be provided at a suitable distance and in a suitable position relative to each other in the wall parts of the longitudinal wall 4 and the bottom cover 6, which include an angle relative to each other.

Since the first end 15 is mounted in the longitudinal wall 4, the fan 26 can be mounted against the lateral side of the storage vessel 2, so that it does not result in extra overall height. Moreover, the fan 26 is thereby readily accessible for maintenance and (dis)assembly. Moreover, above the horizontal part 13 of the heat exchanger, a space 27 can be created from which relatively hot water can be tapped, which space 27 can moreover be used for positioning other heat-exchanging means, as will be further explained hereinbelow with reference to other variants. Furthermore, in this embodiment, the entire outer face of the burner space 14 can be used for heat exchange with the water. A further advantage of the bend included in the heat exchanger 3 is that the heat exchanger 3 has a relatively great length between the first 15 and the second end 23, while the total overall height H is relatively small. Thus, it can be used in a storage vessel 2 with a favorable ratio between contents and outside surface.

A heating apparatus 1 according to Fig. 1 can be used as follows.

The storage vessel 2 and the heating circuit 9 are filled with water and the heating apparatus 1 is connected in a suitable manner. Next, by means of the fan, a gas-air mixture is fed into the burner 17 and combusted. The heated flue gases may or may not be passed along the wall of the burner space 14 and then passed, via the meandering passages between the first elements 22 which increase the heat-transferring area, to the flue gas discharge, while exchanging heat via the wall of the heat exchanger to the water in the storage vessel. The heated water wall flow upwards along the heat exchanger 3 towards the space 27 above the horizontal part 13, while relatively cold water, at least water having a lower temperature, will passed downwards adjacent the longitudinal wall 4. As a result, a favorable flow pattern in the storage vessel is obtained. As at the bottom of the storage vessel 2, the water will have a relatively low temperature, in particular because at this location, the water is returned from the heating circuit 9, the flue gases in the heat exchanger 3 will be cooled down substantially, so that condensation of the flue gases occurs. The condensate flows away easily, in particular due to the vertical position of the vertical part 20. Thus, a condensing heating apparatus of a high efficiency is obtained in a simple manner.

The heating apparatus further comprises thermostat means or otherwise suitable temperature-measuring and switching means 28 for switching on and off the burner and/or the pump, according to the heat demand established. Such circuits controlled by temperature and/or heat demand are known per se. The water for the space-heating circuit 9 can thereby be maintained at a suitable temperature in a simple and energetically advantageous manner.

Fig. 2 shows a second embodiment of a heating apparatus 101 according to the invention, with a first tapping coil 130 included in the space 127 located above the burner space 114. This first tapping coil 130 can for instance be connected to a sanitary-water tapping circuit (not shown). This first tapping coil 130 may extend entirely above the burner space 114, but may also extend for instance spirally around the horizontal part 113 of the heat exchanger 103. This may for instance be advantageous when little space is available and when a rapid response time for tapping warm sanitary water is desired (the so-called convenience time).

A second tapping coil 131 is included adjacent the bottom end of the storage vessel 102, where, during use, the return water of the space-heating circuit 109 is introduced into the storage vessel 102 and the water in the storage vessel 102 has a relatively low temperature. This second tapping coil 131 is for instance particularly suitable for connection to a floor-heating circuit (not shown) or a like low-temperature heating circuit. In the embodiment shown, the second tapping coil 131 is depicted next to the bottom end of the heat exchanger 103, with the longitudinal direction of the coil approximately parallel to the axis of the vertical part 120 thereof, but it may also extend along the inside of the longitudinal wall 104 of the storage vessel 102. As a result, the coil has a greater wound length relative to the height and is substantially disposed in the downwardly directed flow of the water, discussed hereinabove, in the storage vessel 102.

Fig. 3 shows a third embodiment of a heating circuit 201 according to the invention. In this embodiment, the heat exchanger 203 extends between the top cover 205 and the longitudinal wall 204 of the storage vessel 202. In this embodiment, the burner space 214 extends in the upper portion of the vertical part 220, with the heat-exchanging part 221 partially extending in line with the burner space 214 and partially in the horizontal part 213. The fan 226 may be arranged on the top cover 205, as a blowing fan, but may also be provided on the flue gas-discharge side, hence at the second end 223, against the longitudinal wall 204, as a suction fan.

An embodiment according to Fig. 3 can for instance be advantageous when at the bottom a space 227A of a relatively low temperature is desired, or when for instance a non-condensing heating apparatus is desired, although this may in fact be of a condensing type. Moreover, this embodiment has the advantage that it can have its bottom cover 206 arranged against or at least adjacent a floor or like constructional part. After all, no flue gas discharge or the like has to be connected at the bottom side. Moreover, in this embodiment, the burner space 214 is located adjacent the upper end of the storage vessel, the hottest position during use. In this manner, it is optimally provided that water is directly heated up to a maximum temperature, precisely before the heated water can leave the storage vessel 202 to the supply pipe of the heating circuit 209. Such apparatus is for instance advantageous if the storage vessel 202 has a relatively small capacity and a relatively short convenience time is desired for the central heating circuit 209.

Around the burner space and at least the vertical part 220 of the heat exchanger, a first tapping coil 230 extends adjacent the longitudinal wall 204 of the storage vessel 202. This tapping coil is wound between a first end 232 and a second end 233. The first end 232 and the second end 233 are both fixedly connected to the top cover 205 in which the first end of the heat exchanger 203 is mounted. The heat exchanger 203 and the first tapping coil 230 can, together with the top cover 205, be slid into the storage vessel in a simple manner, after which the second end of the heat exchanger can be connected to the longitudinal wall 204. Thus, the heat exchanger and the tapping coil can be installed in a simple manner, while they are positionally fixed relative to each other. In this embodiment shown, a burner 217 of a flat or slightly bent burner deck is used, wherein during use, the flames are directed substantially downwards, in the direction of the heat-exchanging area 221. As a matter of fact, such burner may also be entirely or partially cast integrally with the heat exchanger.

Fig. 4 shows a fourth embodiment of a heating apparatus 301 according to the invention, wherein the heat exchanger is of a U-shaped design. The burner space 314 is provided in a first, horizontally extending leg 313. The connecting means for the flue gas discharge are provided at the second end 323 of the heat exchanger 303, on the second leg 313A which extends parallel to the first leg 313. The heat-exchanging area 321 is included in the at least substantially vertically extending connecting part 320 of the two

legs

313, 313A. From the first end 315 of the heat exchanger 303, the burner 317 is inserted into the burner space 314. Provided around the first end 315 is a first flange 340 having a larger outside circumference than the first opening 316. Provided around the second end 323 is a second flange 341 having an outer circumference that is smaller than the first opening 316 but larger than the second opening 324. The heat exchanger 303 can be inserted through the first opening 316 into the storage vessel 302, with the second end in leading position, and be slid further until the connecting part 320 between the

legs

313, 313A abuts against the outer side of the longitudinal wall 304. Next, the heat exchanger is tilted, so that this connecting part 320 can be slid inside as far as the first leg 313. Contiguously, the heat exchanger is tilted once again, so that the first leg 313 can be slid into the storage vessel 302 as well and the first flange 340 abuts against the outside of the longitudinal wall 304. The first opening 316 and the second opening 325 are positioned one above the other with an interspace such that in the above-described position of the heat exchanger, the second flange 341 abuts against the longitudinal wall 304 on the inside, around the circumference of the second opening 325. The longitudinal wall 304 and the

flanges

340, 341 are provided with corresponding holes, so that the flanges, with the interposition of appropriate packings, can be screwed down against the longitudinal wall in a sealing manner.

Connected to the heating apparatus 301, between the water-supply connecting means 307 and the water-discharge connecting means 310, is a heating circuit, for instance as shown schematically in Fig. 4A or Fig. 4B.

Fig. 4A shows a heating circuit 301 comprising a space-heating circuit 309, schematically depicted by a radiator 380, and a sanitary water circuit 350, schematically depicted by a plate heat exchanger 352 and a water tap 355. Via a first controllable three-way valve 360, the supply pipe 311 is at one end connected to the space-heating circuit 309, and at the other to the feed side of the plate heat exchanger 352. The return pipes 381 and 356 of the space-heating circuit 309 and the plate heat exchanger 352 respectively are jointly connected to a water pump 312. The other side of the pump 321 is connected to a first side of a second controlled three-way valve 365. The other two sides of the second three-way valve 365 are connected to the supply pipe 311 and the return pipe 308 respectively.

During use, hot water can be passed from the storage vessel 302 to the heating circuit 309 and/or the sanitary water circuit 350, depending on the setting of the first three-way valve 360. To the hot water supplied, relatively cool return water from the two

heating circuits

309 and 350 can be added via the second three-way valve 365. In this respect, the pump 312 provides control of the water in the proper direction. By setting the two

control valves

360, 365, water of a suitable temperature and in a suitable quantity is in each case fed to the

heating circuits

309 and 350, depending on the measured water temperatures in the storage vessel 302 and the return pipe and the heat demands in the respective circuits.

Fig. 4B shows a heating circuit comparable with the heating circuit according to Fig. 4A, wherein two pumps and non-return valves and only one controlled three-way valve are included. In this apparatus, hot water is directly supplied from the storage vessel 302 to the two

heating circuits

309, 350. Via the control valve 360, relatively cool water can again be admixed from the return pipe. The non-return valves 366, 367 provide that water from one circuit 309 cannot directly be pumped into the other circuit 350 and vice versa. Depending on the heat demand in the two

heating circuits

309, 350, the pumps 312, 312A are controlled for circulating in the relevant circuit 309, 350 a suitable quantity of water of a suitable temperature. Thus, in each heating circuit, the heat demand can always be satisfied in a quick, comfortable and energetically favorable manner.

Of course, in a comparable manner, several circuits can be connected. The same and comparable heating circuits can moreover be applied to other heating circuits according to the invention.

Of course, differently shaped heat exchangers, for instance as shown in Figs. 1-3 or Fig. 5, to be further described hereinbelow, may also be mounted in a comparable manner in a storage vessel which is already closed in advance or which is still partially open. Such manner of mounting has the advantage that the heat exchanger can be inserted into a vessel which is already substantially closed, and can be fastened from the outside. In this regard, the position of the heat exchanger within the storage vessel is defined by the position of the relevant openings in the storage vessel. These openings may for instance both be located in the longitudinal wall, one directly above the other, or for instance on opposite sides of the longitudinal wall. Also, one of the openings may be located in a cover and the other opening may be located in the longitudinal wall, or, optionally, both openings may be located in the respectively covers. The fastening flanges and/or packings may be of such design that small relative movements of the heat exchanger relative to the longitudinal wall are possible, so as to take up a difference in expansion of the heat exchanger and the storage vessel. This is important in particular when the two ends of the heat exchanger are incorporated into the same longitudinal wall.

Fig. 5 shows a fifth embodiment of a heat exchanger 401 according to the invention, wherein the heat exchanger is of a substantially Z-shaped design. The burner space 414 is provided in a first, horizontally extending leg 413. The connecting means for the flue gas discharge are provided at the second end 423 of the heat exchanger 403, on the second leg 413A which extends parallel but in opposite direction. The heat-exchanging area 412 is included in the connecting part 420 between the two

legs

413, 413A, which connecting part extends at least substantially in vertical direction. Around the connecting part 420 a tapping coil 430 extends, adjacent the longitudinal wall 404. This tapping coil 430 can for instance be accommodated in a floor-heating apparatus or the like. From the bottom cover 406, a first, relatively short connecting pipe 450 extends into the storage vessel 402, as well as a second, relatively long second connecting pipe 451. Included between the two connecting

pipes

450, 451 is a heating circuit 409, comprising for instance a plate heat exchanger 452. By means of a pump 453, water can be pumped through this circuit, through the plate heat exchanger 452. In the plate heat exchanger 452, sanitary water can for instance be heated up through heat exchange, which water can be drawn off via a tap or the like. Such circuit 454 is shown schematically in Fig. 5.

The invention is by no means limited to the embodiments shown in the drawings and described. Many variations thereto are possible.

For instance, the heat exchangers shown in the various Figures may be combined with the various storage vessels and/or tapping coils shown. Moreover, in each of these embodiments, a different number of tapping coils may be used, as well as, for instance, a heating circuit having a heat exchanger as shown in Fig. 5. The flat heat exchanger included therein may of course also be a heat exchanger of another type. The fins 25 shown in Fig. 1, which fins extend in the longitudinal direction of the heat-exchanging area 21 and which act as elements increasing the heat-transferring area, may of course also be designed differently, for instance spirally, as projections, radial partitions, or like suitable shapes. Moreover, a sleeve may be provided which surrounds the heat-exchanging area at least partially and at some distance, which sleeve ends at some distance from the first and the second end of the heat exchanger. This allows the flow of water between the heat exchanger and the sleeve, whereby the natural flow within the storage vessel can be controlled.

These and many comparable modifications and variations are understood to fall within the framework of the invention.

Claims

A heating apparatus, comprising a storage vessel and a heat exchanger extending in the storage vessel, which heat exchanger comprises a burner space and, connecting thereto, a heat-exchanging part and is provided with gas mixture-supply means for a gas-air mixture to burner means disposed in the burner space and flue gas-discharge means, wherein the storage vessel comprises water-supply means and water-discharge means, wherein the heat exchanger is substantially manufactured through casting from light metal and the vessel is substantially manufactured from sheet material,
characterized in that the gas mixture-supply means are disposed adjacent a first end of the heat exchanger and the flue gas-discharge means are disposed adjacent a second end spaced from the first end, wherein the first end of the heat exchanger is located adjacent the top side of the storage vessel in a first wall part of the storage vessel and the second end is located adjacent a bottom side of the storage vessel in a second sheet part, and wherein the storage vessel is adapted for storing and feeding through water for use in a space-heating circuit.
A heating apparatus according to claim 1, characterized in that between the first and the second end, at least one bend is included in the heat exchanger.
A heating apparatus according to any one of the preceding claims, characterized in that the storage vessel comprises a sidewall, a top cover and a bottom cover, wherein the first sheet part is a portion of one of the covers and the second sheet part is a portion of the wall or the other way round.
A heating apparatus according to any one of claims 1-3, characterized in that the first sheet part forms part of one of the covers and the second sheet part forms part of the other cover.
A heating apparatus according to any one of claims 1-3, characterized in that the first and the second sheet part both form part of the sidewall.
A heating apparatus according to any one of the preceding claims, characterized in that at least one tapping coil is provided which extends in the storage vessel, spaced from the heat exchanger.
A heating apparatus according to claim 6, characterized in that said, at least one tapping coil surrounds at least a portion of the heat-exchanging part and extends adjacent the outer wall of the storage vessel.
A heating apparatus according to claim 6 or 7, characterized in that at least one tapping coil extends adjacent the upper side in the storage vessel, preferably at least partially above the burner space.
A heating apparatus according to any one of the preceding claims, characterized in that the heat exchanger, in particular the heat-exchanging part, has its outside provided with preferably integrally cast elements which increase the heat-transferring area.
A method for manufacturing a heating apparatus according to any one of claims 1-4, characterized in that the wall of the storage vessel is manufactured, wherein an opening is provided in the wall for receiving one end of the heat exchanger, wherein the heat exchanger is cast and has its relevant end mounted in the opening, wherein a cover is provided with an opening for receiving the other end of the heat exchanger, said cover being welded on the wall and wherein the relevant end is mounted in the opening in the cover, whereafter the storage vessel is closed by mounting the second cover, preferably through welding.
A method according to claim 10, characterized in that prior to mounting the relevant cover on said end of the heat exchanger and the wall of the storage vessel, at least one tapping coil is provided around at least a portion of the heat exchanger, said tapping coil being preferably connected to the relevant cover.
A method for manufacturing a heating apparatus according to claim 5, characterized in that in the sidewall of the storage vessel a first and a second opening are provided so as to be substantially one above the other, wherein the first opening is larger than the second opening and the heat exchanger is of a substantially U-shaped design, in such a manner that the first and the second end extend approximately in the same plane, spaced apart a distance corresponding to the distance between the first and the second opening, wherein one of the ends of the heat exchanger is passed through the first opening to a position adjacent the other end, and is tilted, in such a manner that the leading end is moved against the second opening, after which the first and the second end of the heat exchanger are sealingly connected to the sidewall of the storage vessel, the arrangement being such that the flue gas-discharge means and the gas mixture-supply means are accessible from the outside of the storage vessel, while the storage vessel is closed in a watertight manner.
A method for controlling the heat supply to a heating circuit when a heating apparatus according to any one of claims 1-9 is used, wherein relatively cold return water is mixed with relatively warm water from the storage vessel, depending on the heat demand and/or the water temperatures, the arrangement being such that the heat demand can in each case be satisfied in a suitable manner, without involving thermal shocks.