DE102007026968A1 - Heat exchanger has interconnected loops arranged in axial direction, with at least one having inclined tube section which is inclined to axial direction, and non-inclined tube section extending perpendicularly to axial direction - Google Patents

Abstract

The heat exchanger comprises a number of interconnected loops (50) arranged in the axial direction, at least one of which has an inclined tube section which is inclined in relation to the axial direction, and a non-inclined tube section which extends perpendicularly to the axial direction. The inclined tube section is provided in each of opposite end sections in a width direction crossing the axial direction, while the non-inclined tube section is provided in a mid-section in the width direction. Independent claims are included for the following: (1) a hot water boiler which has a burner (3) and a heat exchanger (B); and (2) a water tube (11) for a heat exchanger.

Description

TECHNICAL AREA

The The invention relates to a heat exchanger for Heat recovery from combustion gases using a water pipe with a helical pipe body for Generating hot water. The invention further relates to a water heater, the with such a heat exchanger is provided, and a water pipe for a heat exchanger.

STATE OF THE ART

Examples from conventional heat exchangers are given in the publication JP-PS 2,835,286, Japanese Laid-Open Patent Publication 62-288446, and the published JP-GM publication 6-8442. For the heat exchanger given in these documents is a helical tube body a water pipe housed in a jacket into which a combustion gas is to be initiated. warmth is recovered from the combustion gas through the helical tube body, so that the Water pipe supplied Water is heated. In comparison with a straight running tube body has a helical tube body a larger heat transfer cross section. With the heat exchanger can thus the recovered heat increased while reducing the number of water pipes become.

at However, the known construction described above occur following problems.

As 9 schematically shows, has the helical tube body 9 the water pipe in the known construction a plurality of loops 90 on, which are continuously connected to each other and in the axial direction (the direction in which the central axis of the helical tube body 9 runs) are arranged. Each of the loops 90 is inclined over its entire length at a predetermined angle θ. In this construction, the height h1 is half a range of a loop 90 given by h1 = L · tanθ, and the pitch p1 of the helical tube body 90 is given by p1 = 2 · h1 = L · tanθ, where L is the diameter or the width of the helical tube body 9 is.

Therefore, the slope p1 is relatively large. To increase the amount of heat to be recovered by the water pipe, the number of loops 90 increase. However, since the dimensions h1 and p1 are relatively large, the overall height h of the helical tube body becomes 9 very big, if the number of loops 90 is increased. Therefore, the conventional construction has the disadvantage that the overall height of the helical tube body 9 gets very big when the number of loops 90 is increased to increase the heat recovery amount.

In In the cold season, for example, the use of a water heater, with a heat exchanger is over be interrupted for a long time. In such a case, the water can be drained from the water pipe to prevent the interior of the water pipe freezes. It is therefore desirable that the problem described above solved in terms of the greater height, without complicating the emptying of the water pipe.

DISCLOSURE OF THE INVENTION

task The invention is the solution or alleviation of the above problems.

to solution This object of the invention provides the following technical measures in front.

According to one The first aspect of the present invention is a heat exchanger indicated that a jacket in which to introduce a combustion gas is, and a water pipe for heat recovery from the combustion gas. The water pipe is in the mantle housed and has a helical tube body, which a variety of loops, which has been arranged in the axial direction and continuously connected to each other. At least one of the loops has one inclined pipe portion inclined with respect to the axial direction is, and a non-inclined Pipe region which extends perpendicular to the axial direction. The inclined tube portion is at each of opposite end portions in a width direction crossing the axial direction provided during the non-inclined pipe portion at an intermediate portion in the width direction is provided.

Prefers Show everyone Sanding a sloped pipe section and a non-inclined pipe section on.

Prefers Each of the loops has a pair of straight pipe sections in the width direction and substantially parallel to each other, and a pair of curved ones Pipe areas that are connected to ends of the straight pipe sections. Each of the straight pipe sections is the non-inclined pipe section, while each of the curved ones Pipe areas of the inclined pipe area is.

Preferably, the helical tube body is disposed in the shell so that the loops are vertically arranged, and the shell has a pair of walls between which the helical tube body is arranged in the horizontal direction. The wall pairs are formed with a gas supply opening and a gas outlet opening, respectively, and inserted into the shell through the gas supply opening The combustion gas flows through a gap between adjacent loops and is discharged from the jacket through the gas outlet port.

Prefers the water pipe has an extension on, which is connected to a lower end of the helical tube body, and a Part of the extension is outside of the jacket arranged. This part has a curved area on, that's how curved is that his Height in Course to an end of the extension is reduced.

According to one second aspect of the present invention is a water heater specified, which has a burner and a heat exchanger. The heat exchanger comprises a jacket into which the combustion gas is to be introduced, and a water pipe for heat recovery from the combustion gas. The water pipe is housed in the jacket and has a helical tube body on, which has a variety of loops, in the axial direction arranged and connected to each other continuously.

At least one of the loops has a sloped pipe portion which is related to is inclined to the axial direction, and a non-inclined pipe portion on, which extends perpendicular to the axial direction. The inclined one Pipe area is at each of opposite end areas in a width direction crossing the axial direction provided during the non-inclined pipe portion at an intermediate portion in the width direction is provided.

According to one Third aspect of the present invention is a water pipe for a heat exchangers specified. The water pipe has a helical tube body, which has a plurality of loops arranged in the axial direction and are continuously connected. At least one of the Grinding has a sloping tube area which is relative to the Axial direction is inclined, and a non-inclined tube portion, which is perpendicular extends to the axial direction. The inclined pipe area is on each of opposite end portions provided in a width direction crossing the axial direction, while the non-inclined pipe portion at an intermediate portion in the width direction is provided.

Further Features and advantages of the present invention will become apparent the following description of embodiments with reference on the attached Drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The Drawings show in:

1 a front view schematically showing an example of a water heater according to the invention;

2 a front view of a main area of in 1 shown water heater;

3 a sectional view taken along the line III-III in 1 ;

4 a side view of a main area of in 1 shown water heater;

5A a horizontal section of a secondary heat exchanger of in 1 shown water heater, and

5B in section, a front view thereof;

6A a plan view of an example of a water pipe of the in the 5A and 5B shown secondary heat exchanger, and

6B a sectional view taken along the line VI-VI in 6A ;

7 a schematic view of the in the 6A and 6B shown water pipe;

8th a horizontal section of another example of a heat exchanger according to the present invention; and

9 a schematic view of an example of a conventional construction.

BEST MODE OF IMPLEMENTATION OF INVENTION

The Invention will also be described below with regard to further features and Advantages based on the description of embodiments with reference explained in more detail in the accompanying drawings.

The 1 to 6 show an example of a water heater and the associated construction according to the present invention. In these figures, the arrow V denotes the vertical direction, and the arrow H denotes the horizontal direction.

How better in 1 can be seen, the water heater A of this embodiment, a burner 3 , a primary heat exchanger 1 and a secondary heat exchanger B. The secondary heat exchanger B is an example of the heat exchanger to which the present invention is applied.

The burner 3 is in a coat 30 arranged and burns a gas coming from the outside of the mantle 30 through a pipe 32 is supplied. A fan 31 is under the coat 30 arranged so that combustion air from the blower 31 up into the mantle 30 is supplied. The primary heat exchanger 1 is designed to provide sensible heat from the burner 3 recover recovered combustion gas. The primary heat exchanger 1 has a water pipe 11 on top of that, with a variety of ribs 12 is provided and a coat 10 generally penetrating horizontally. The coats 10 and 30 can be integrally formed with each other.

The secondary heat exchanger B is provided to recover latent heat from the combustion gas. The secondary heat exchanger B is above the primary heat exchanger 1 arranged and with the coat 10 over an additional coat 19 connected. The secondary heat exchanger B has a jacket 7 in which a combustion gas is to be introduced, and a plurality of water pipes WT, each having a helical tube body 5 have, and distributors 6A and 6B for the water inlet and the hot water drain.

The coat 7 has is generally cuboid and encloses the helical tube body 5 , As 3 shows, the coat has 7 a back wall 70a or a front wall 70b Coming with a gas supply connection 71 or a gas outlet port 72 are formed. The gas outlet connection 72 may be generally rectangular in shape, such as 2 shows, and the gas supply connection 71 can have a similar shape. This is the primary heat exchanger 1 flowing and upward combustion gas passes into the mantle 7 through the gas supply connection 71 one. In the coat 7 The WT water pipes recover latent heat from the combustion gas.

After recovering the latent heat, the combustion gas passes through the gas outlet port 72 from the coat 7 discharged. When recovering latent heat from the combustion gas, condensed water is generated on the surfaces of the water pipes WT. Therefore, at the bottom wall 70d of the coat 7 an outlet port 73 provided for the discharge of condensation. With this construction, condensed water from the surfaces of the water pipes WT to the bottom wall 70d dripping of the jacket, the condensation is from the mantle 7 through the outlet opening 73 derived.

As the 5A and 5B show, are the respective helical tube body 5 the plurality (for example, five) of water pipes WT in the mantle 7 accommodated. For ease of understanding, reference will be made below with reference to FIGS 6A and 6B the structure of a single water pipe WT described. The water pipe WT shown in the figures can be formed by bending a pipe of a single material.

The water pipe WT has a helical tube body 5 as well as approaches or extensions 51 and 52 integral with a lower end and an upper end of the helical tube body 5 are connected. The helical tube body 5 has a variety of generally elliptical loops 50 , in the axial direction of the helical tube body 5 (in the direction in which the central axis C extends) via gaps 59 arranged and connected to each other continuously.

In this embodiment, the axial direction is the vertical direction V. In the use of the water heater A, the water heater A is installed in a suitable position so that the axial direction corresponds to the vertical direction. In the width direction (the right and left direction in the 6A and 6B ) each of the loops exists 50 from an intermediate region S1 and opposite end regions S2a and S2b. The intermediate region S1 has a pair of straight pipe sections 50a and 50b on, which run parallel to each other.

The straight pipe areas 50a and 50b are perpendicular to the axial direction. The straight pipe areas 50a and 50b are non-inclined pipe portions that are not inclined with respect to the horizontal surface. The opposite end portions S2a and S2b have generally semicircular or arcuately curved tube portions 50c and 50d on. The curved pipe sections 50c and 50d are inclined pipe portions which are inclined with respect to the axial direction and the horizontal surface.

In particular, in 6A the curved pipe area 50c at an appropriate angle inclined so that its height in the course of one end of the straight pipe section 50a to one end of the topmost straight pipe section 50b gradually decreases in the direction indicated by the arrow N1. The straight pipe area 50a is higher than the straight pipe area 50b positioned.

The curved pipe area 50d is inclined so that its height in the course of the other end of the straight pipe section 50b to one end of the straight pipe section 50a the following loop 50 gradually decreases in the direction of the arrow N2. It should be noted that the structure of the straight pipe sections 50a . 50b and the curved pipe sections 50c . 50d the other loops 50 is similar to the above loop.

As the 5A and 5B show, have the helical tube body 5 the variety of water pipes WT different size and are in the mantle 7 generally arranged concentrically. The topmost straight pipe sections 50a . 50b the helical tube body 5 are the inner surface of the upper wall 70c of the coat 7 over a gap 79a facing and generally parallel to the inner surface. The lowest straight pipe sections 50a . 50b the helical tube body 5 are the inner surface of the lower wall 70d of the coat 7 over a gap 79b facing and generally parallel to the inner surface. In this construction, the widths L1 and L2 are the spaces 79a and 79b constant.

One end of each of the extensions 51 . 52 enters through the side wall 70e of the coat 7 out, so it's on the outside of the coat 7 is positioned, and it is with the water inlet manifold 6A or the hot water outlet manifold 6B connected. The distributor 6A has a connection 60A for the water supply, which is used as Wasserauslaßanschluß in discharging water from the water pipes WT. Each of the extensions 51 has a downwardly curved area 51a on, the outside of the coat 7 is positioned.

As described in more detail below, the curved area becomes 51a used to divert water from the water pipe WT, and it may have a curved tube separate from the extension 51 is trained. In this embodiment, the distributor is 6A slightly inclined with respect to the vertical direction V, so that the terminal 60A not oriented vertically downwards. This construction is useful, for example, a conduit 80 for the water inlet.

The distributor 6A but can also be oriented in other ways. Unlike the extension 51 is not one of the extensions 52 with a curved area 51a appropriate part and directly with the hot water outlet manifold 6B connected. As 1 shows, the distributor points 6B a connection 60B for the warm water drain on, which over a line 81 with a water inlet 11a of the primary heat exchanger 1 connected is. In the primary heat exchanger 1 The water supplied from the secondary heat exchanger B flows through the water pipe 11 to be heated further.

The water heated in this way is through a hot water outlet 11b fed to a suitable destination. The order in which water passes through the primary heat exchanger 1 and flows through the secondary heat exchanger B, however, means no limitation. For example, the water may first be the primary heat exchanger 1 and then supplied to the secondary heat exchanger B.

Of the Operation and the advantages of the secondary heat exchanger B and the water heater A, in common with the heat exchanger B is provided will be described below.

If at the in 1 shown water heater the water pipes WT of the secondary heat exchanger B and the water pipe 11 of the primary heat exchanger 1 Water is supplied, the operation of the burner begins 3 , Then from the burner 3 generated combustion gas sensible heat and latent heat through the primary heat exchanger 1 and the secondary heat exchanger B recovered. The hot water generated by the heat recovery is a corresponding destination by the hot water outlet 11b fed.

As already with reference to the 6A and 6B are explained in each loop 50 of the water pipes WT, only the opposite end portions S2a and S2b are inclined with respect to the horizontal surface, and the intermediate portion S1 is horizontal. 7 shows schematically the structure of the loop 50 , In this figure, the height h2 is half a range of the loop 50 given by h2 = 2 · L2 · tanθ, and the pitch p2 of the helical tube body 5 is given by p2 = 2 * h2 = 4 * L2 * tanθ, where L is the width of the loop 50 , L1 is the width of the intermediate region S1, L2 is the width of the opposite end regions S2a, S2b, and θ are the inclination angles of the opposite end regions S2a, S2b.

Thus, the slope p2 is smaller than the slope p1 of in 1 shown conventional construction. In particular, p2 is smaller than p1 by 2 * L1 * tanθ. As can be seen, in the present embodiment, the pitch of the helical tube body 5 be reduced. Even though, therefore, the number of loops 50 is increased to increase the amount of heat recovered, the total height of the helical tube body 5 not so large, so that a significant increase in size of the secondary heat exchanger B can be easily prevented.

Specifically, in the present embodiment, the loops 50 in plan view in general elliptical shape. By extending the straight pipe sections 50a and 50b Therefore, the heat transfer cross section of the water pipe WT can be increased without the height of the helical tube body 5 to enlarge. Thus, the heat transfer efficiency can be increased without making the secondary heat exchanger B large becomes.

In the secondary heat exchanger B, heat is recovered when combustion gas passes through between the loops 50 defined spaces 59 flows. Because the loops 50 , which are arranged in the vertical direction V, have almost identical shape, the width (with L3 in 6B referred to) of the gap 59 generally uniform along the longitudinal direction. Thus, it is possible to prevent combustion gas due to nonuniformity of the width of the gap 59 concentrated flows through a specific area. The combustion gas thus acts on each area of each loop 50 generally uniform. This is also advantageous to increase the amount of heat recovered and increase the heat transfer efficiency.

The combustion gas also flows into the interstices 79a . 79b between the loops 50 and the upper wall 70c and the bottom wall 70d of the coat 7 are defined, and heat is also at the interstices 79a . 79b recovered. The widths L1, L2 of the spaces 79a . 79b are uniform in the areas where the straight pipe sections 50a . 50b exist. Therefore, also at the intervals 79a . 79b Combustion gas are generally uniformly distributed, so that heat can be recovered with good efficiency.

In winter, the operation of the water heater A, for example, is interrupted for a long time. In this case, the freezing of the inside of the primary heat exchanger 1 and the secondary heat exchanger B to prevent the supply of water to the water pipes 11 and WT are interrupted, and they are emptied. In the present embodiment, water can be prevented from remaining in the water pipes WT of the secondary heat exchanger B as described below.

In the helical tube body 5 are the opposite end portions S2a and S2b of each loop 50 inclined. Thus, by providing the inclined end portions S2a and S2b, water flows from a higher to a lower portion of the helical pipe body 5 , Furthermore, because the straight pipe sections 50a and 50b of the intermediate area S1 are horizontal, accumulation of water in these areas is of course prevented. Thus, water flows in the straight pipe area 50a or 50b through the adjacent curved area 50c or 50d to the following loop 50 , In this way, the emptying of the water pipes WT can be performed properly.

To increase the amount of recovery of latent heat, it is preferable that each water pipe WT of the secondary heat exchanger B be thinner than each water pipe 11 of the primary heat exchanger 1 is. However, if the water pipe WT is thin, ie has a small diameter, may be at the end opening or mouth of the extension 51 form a water layer or a water film due to the surface tension. Such a water film impedes the emptying of the water pipe WT.

In the present embodiment, however, the water film may be broken by the dynamic pressure in the curved portion 51a the extension 51 is available. So water can come from the mouth of the extension 51 unhindered to the distributor 6A be derived. In the present embodiment, the range of extension is 51 , which is closer to the helical tube body 5 as at the curved area 51a is, horizontal. However, in the present invention, this area may be inclined to control the flow of water from that area towards the manifold 6A to facilitate.

The The present invention is not in the above embodiment limited. A special construction of each part of the heat exchanger, the water heater and the water pipe of the heat exchanger can be modified in various ways with respect to the design become.

The loops of the helical tube body of the water pipe may not be elliptical in plan view, but may have another shape. 8th Fig. 10 shows an example of the water pipe having a shape different from that of the above embodiment. In this figure, elements that are identical or similar to those of the previous embodiment are denoted by the same reference numerals as there.

In the example shown, the loop has 50 of the innermost water pipe WT has a construction similar to that of the previous embodiment, that is, it has opposite end portions S2a and S2b curved into a semicircular shape or an arc shape. The loops 50A The other water pipes WT which are positioned on the outside are generally rectangular in plan view, and their opposite end portions S2a and S2b are curved to have a straight portion, and the radius of curvature of the curved portions is small.

In this construction, a part of the helical tube body 5 at or near the four corners 78 of the coat 7 be arranged so that the dead space within the shell 7 can be reduced. In the present invention, the Loops also have a different shape than that described above. For example, the loops may have a generally square shape or a generally circular shape.

at In the present invention, the number of water pipes means none Restriction. The use of only a single water pipe is not very practical, but it is possible and the present invention is also in such a construction applicable. Although it is preferred that all loops of the helical tube body in inclined horizontally in the intermediate region and in opposite end regions are but the present invention is not limited thereto. at of the present invention even some of the loops have such a construction.

Also in this case can be opposite a conventional one Construction of the degree of heat recovery increased while an increase in the height of the helical tube body can be avoided. In the present invention, the terms "opposite End ranges "and" intermediate range "of the loop in the width direction only the positional relationship between areas a loop. The dimension or the dimension ratio of this Areas is therefore not limiting.

The Although the present invention is in the case of the previous embodiment not at a primary heat exchangers to recover tangible Applied heat, but the heat exchanger according to the present Invention is not on a heat exchanger for recovery sensible heat or for recovery latent heat limited.

When Burner of the water heater according to the present invention For example, a burner other than a gas burner may be used can be an oil burner be used. The system for flowing combustion gas in the jacket of the heat exchanger and for the action of the combustion gas on the water pipes not limited to the foregoing embodiments. For example the combustion gas can be conducted to the interior of the helical tube body and be brought to, through the spaces between the loops to the outside of the helical tube body to stream.

Of the Water heater refers to in the present invention Devices whose function is the production of hot water, and includes various devices for the supply of hot water for general use, as bathwater, for the space heating or melting of snow, etc. as well as devices for generating hot water for other purposes than the hot water supply.

Claims (7)

Heat exchanger (B), comprising: - a jacket ( 7 ) into which a combustion gas is to be introduced; and - a water pipe (WT) for heat recovery from the combustion gas, the water pipe in the shell ( 7 ) is housed and a helical tube body ( 5 ) having a plurality of loops ( 50 ) arranged in an axial direction and continuously connected to each other; - at least one of the loops ( 50 ) an inclined pipe area ( 50c . 50d ), which is inclined with respect to the axial direction, and a non-inclined pipe region (US Pat. 50a . 50b ) which extends perpendicular to the axial direction, wherein the inclined pipe region ( 50c . 50d ) is provided in each of opposite end portions (S2a, S2b) in a width direction crossing the axial direction, while the non-inclined pipe portion (FIG. 50a . 50b ) is provided in an intermediate portion (S1) in the width direction. Heat exchanger according to claim 1, characterized in that all loops ( 50 ) the inclined pipe area ( 50c . 50d ) and the non-inclined pipe area ( 50a . 50b ) exhibit: Heat exchanger according to one of claims 1 or 2, characterized in that each loop ( 50 ) comprises: a pair of straight pipe sections ( 50a . 50b ) extending in the width direction and substantially parallel to each other, and a pair of curved pipe portions (FIG. 50c . 50d ) connected to ends of the straight pipe sections ( 50a . 50b ) are connected; each of the straight pipe sections ( 50a . 50b ) is the non-inclined tube region, while each of the curved tube regions ( 50c . 50d ) is the inclined pipe area. Heat exchanger according to one of claims 1 to 3, characterized in that the helical tube body ( 5 ) in the jacket ( 7 ) is arranged so that the loops ( 50 ) are arranged vertically; the coat ( 7 ) a pair of walls ( 70a . 74b ), between which the helical tube body ( 5 ) is arranged in a horizontal direction, and wherein the pair of walls with a gas supply connection ( 71 ) and a gas outlet port ( 72 ) is trained; and where in the mantle ( 7 ) through the gas supply connection ( 71 ) introduced combustion gas through egg interspace ( 59 ) between adjacent loops ( 50 ) flows through the gas outlet port ( 72 ) from the coat ( 7 ) is discharged. Heat exchanger according to claim 4, characterized in that the water pipe (WT) is an extension ( 51 . 52 ) having a lower end of the helical tube body ( 5 ) connected is; and that part of the extension ( 51 . 52 ) outside the coat ( 7 ) and this part with a curved area ( 50d ) which is curved so that its height in the course of an end of the extension ( 51 . 52 ) is reduced. A water heater comprising a burner and a heat exchanger, the heat exchanger comprising: - a jacket ( 7 ), is to be introduced into the combustion gas; and - a water pipe (WT) for heat recovery from the combustion gas, the water pipe in the shell ( 7 ) is housed and a helical tube body ( 5 ) having a plurality of loops ( 50 ) arranged in an axial direction and continuously connected to each other; at least one of the loops ( 50 ) an inclined pipe area ( 50c . 50d ), which is inclined with respect to the axial direction, and a non-inclined pipe region (US Pat. 50a . 50b ) which extends perpendicular to the axial direction, wherein the inclined pipe region ( 50c . 50d ) is provided in each of opposite end portions (S2a, S2b) in a width direction crossing the axial direction, while the non-inclined pipe portion (FIG. 50a . 50b ) is provided in an intermediate portion (S1) in the width direction. Water pipe for a heat exchanger, wherein the water pipe (WT) a helical tube body ( 5 ) having a plurality of loops ( 50 ) arranged in an axial direction and continuously connected to each other; at least one of the loops ( 50 ) an inclined pipe area ( 50c . 50d ), which is inclined with respect to the axial direction, and a non-inclined pipe region (US Pat. 50a . 50b ) which is perpendicular to the axial direction, wherein the inclined pipe portion is provided in each of opposite end portions (S2a, S2b) in a width direction crossing the axial direction, while the non-inclined pipe portion is provided in an intermediate portion (S1) in the width direction is.