CN214664322U

CN214664322U - Heat exchange device and hot water boiler and steam generation equipment thereof

Info

Publication number: CN214664322U
Application number: CN202120726402.5U
Authority: CN
Inventors: 岳俊
Original assignee: Anhui Hot Well Energy Saving Technology Co ltd
Current assignee: Anhui Rejing Boiler Co ltd
Priority date: 2021-04-10
Filing date: 2021-04-10
Publication date: 2021-11-09
Anticipated expiration: 2031-04-10

Abstract

The invention discloses a heat exchange device with energy saving, high efficiency and high reliability, a hot water boiler and steam generating equipment thereof, wherein the heat exchange device comprises: the heat exchanger comprises a first heat exchange unit and a second heat exchange unit surrounding the first heat exchange unit; the inner space surrounded by the first heat exchange unit is configured as a combustion chamber; wherein the second heat exchange unit is communicated with the upstream of the first heat exchange unit along the flow direction of the heated medium; the first heat exchange unit is formed by spirally forming a finless heat exchange tube; the second heat exchange unit is spirally formed by fin heat exchange tubes.

Description

Heat exchange device and hot water boiler and steam generation equipment thereof

Technical Field

The invention relates to the field of steam generation equipment, in particular to a heat exchange device, a hot water boiler and steam generation equipment thereof.

Background

Under the promotion of national policies of energy conservation and emission reduction, the development of gas combustion equipment (gas water heating equipment/steam generating equipment) to a full-premixing condensing technology with high efficiency and low emission is accelerated. Especially, the fast gas steam generating device has small water volume, has fast steam generating speed compared with the traditional steam boiler, does not need regular annual inspection, is widely favored by the market, and is widely applied to national production and life, such as hotels, guesthouses, food, textile, chemical industry, feed and other industries. However, the existing rapid gas steam generation equipment in the market generally has the defects of poor reliability, high emission of nitrogen oxides, low efficiency, large size and the like.

For example: the steam generating apparatus disclosed in publication No. CN105402710A employs a split modular technique. The boiler flue gas has high nitrogen oxide emission, does not meet the low emission environmental protection requirement, has the flue gas oxygen content of about 11 percent, has large surplus coefficient, takes away much heat by excessive air, and has low heat efficiency. The assembly of multiple components has a plurality of parts (such as gas valves, fans, burner groups, heat exchanger groups, wind pressure switches and the like), and the corresponding failure rate is high. In addition, the steam generating equipment adopts the three-layer fin type heat exchanger, after long-term combustion, due to uneven heating, water leakage is easy to occur at the deformed copper pipes and welding positions between the heat exchangers of different stages due to deformation, overheating and melting are easy to occur on the fins on the fire-facing side, and the heat exchangers are limited by volume and have small evaporation capacity.

The heat exchanger unit disclosed in publication No. CN109373302A adopts the integrated technology of thick and thin burning fire rows, solves the low nitrogen emission problem of equipment, but still has the high failure rate problem caused by the multi-component assembly and the multiple parts. Particularly, the heat exchanger unit adopts the stainless steel light pipe and the fin combined pipe as an evaporation section and a superheating section, and the copper fin type heat exchanger as a preheating section, so that when the burners are combusted in groups, the length direction of the heat exchanger is uneven in cooling and heating, and the problem of deformation and bending of the heat exchanger is easy to occur after long-term use.

Publication No. CN107781800A provides a circulating steam boiler which adopts a through-flow type full premixing technology, vertical multi-pipe parallel connection and upper and lower header welding. But the boiler has the defects of multiple welding spots, complex processing technology and poor reliability, and due to the adoption of a parallel structure, the uneven water flow distribution and the cracking of the heat exchange tube due to the overheating stress are easy to occur after the boiler is used for a long time. Meanwhile, the heat exchanger needs an additional water level detector to detect the liquid level height, and the heat exchange tube is prone to overheating if the height detection is inaccurate, so that the service life of the heat exchanger is influenced.

Publication No. CN112097234A provides a coil type steam generator which adopts a straight-flow type full premixing technology and a three-layer stainless steel coil series connection mode, the scheme solves the problem that other schemes have more welding spots, and meanwhile, the heat exchange capacity is improved by utilizing the change-over flow of smoke for 4 times. However, the smoke in the scheme is always in a laminar flow state, the flow is not fully disturbed, and the heat exchange in the middle area of the fluid cannot be fully realized; and only utilize the heat transfer area of the inside and outside both sides of heat transfer coil pipe, the heat transfer area between the pipe is all failed to be used for the heat transfer, therefore effective heat transfer area is less, leads to the coil pipe overlength, and the water resistance is big, and is bulky, needs additionally to increase a large-scale energy-saving appliance to come the raising efficiency when the water volume is big, and the cost is very high.

Publication No. CN103512018B also provides a steam generator using a straight-flow full-premixing technique and a single coil in series, which solves the problem of many welding spots, but also has the problem of not utilizing the effective heat exchange area between tubes, and the heat exchange efficiency is low. And only a round coil pipe is needed, the flue gas can not fully exchange heat, and in order to improve the heat exchange quantity, the coil pipe must be prolonged, so that the problem that the water capacity of the coil pipe is too large and the volume is too large is solved.

The inventor researches and discovers that the steam generating equipment disclosed in the patent is provided with the light pipes for heat exchange, in order to increase the heat transfer area of the pipe wall, the light pipes (rings) are attached to the light pipes (rings), although the light pipes with more lengths can be accommodated under a certain volume, the light pipes cannot be attached to the rings to leave smoke, a part of heat exchange area is sacrificed, so that the heat exchange efficiency is not high, sometimes, an energy saver is required to be additionally arranged to meet the steam output requirement, the cost is increased, the volume is easy to exceed the standard, and the standard requirement cannot be met.

In addition, a heat exchanger of the conventional gas-fired hot water boiler is provided with a heat exchange pipe for exchanging heat with flue gas. For increase outside of tubes heat transfer area, increase the heat transfer volume of heat exchange tube, the heat exchange tube generally adopts the finned tube, and a lot of fins are processed on the finned tube passes through the surface of body for original surface obtains the extension, promotes heat transfer area, promotes the heat transfer volume. However, the heat exchanger of the existing hot water boiler has short service life in the using process, and the using experience of users is influenced.

Disclosure of Invention

In view of the above problems of the prior art, it is an object of the present invention to provide a rapid heat exchanger, a hot water boiler and a steam generating apparatus thereof, which are energy-saving, efficient and highly reliable, so as to solve at least one of the above problems.

In order to achieve the purpose, the invention adopts the following technical scheme:

a heat exchange device comprising: the heat exchanger comprises a first heat exchange unit and a second heat exchange unit surrounding the first heat exchange unit; the inner space surrounded by the first heat exchange unit is configured as a combustion chamber; wherein the second heat exchange unit is communicated with the upstream of the first heat exchange unit along the flow direction of the heated medium; the first heat exchange unit is formed by spirally forming a finless heat exchange tube; the second heat exchange unit is spirally formed by fin heat exchange tubes.

In a preferred embodiment, the first heat exchange unit comprises one or two or three inner heat exchange coil tubes formed by extending heat exchange tubes spirally.

In a preferred embodiment, the first heat exchange unit comprises two or three inner heat exchange coil pipes which are sleeved; wherein, along the flow direction of the heated medium, the inner heat exchange coil barrel positioned at the innermost side is communicated with the upstream of other inner heat exchange coil barrels.

As a preferred embodiment, of the at least two inner heat exchange coil tubes, the inner cross-sectional area of the heat exchange tube of the outer inner heat exchange coil tube is larger than the inner cross-sectional area of the heat exchange tube of the inner heat exchange coil tube. (steam generating apparatus)

As a preferred embodiment, in adjacent two inner heat exchange coil barrels, the heat exchange tube of the inner heat exchange coil barrel positioned at the outer side has an inner cross-sectional area 1.1 times to 3.1 times as large as that of the inner heat exchange tube of the inner heat exchange coil barrel positioned at the inner side.

In a preferred embodiment, the heat exchange tubes of at least two of the inner heat exchange coil tubes have equal inner cross-sectional areas.

In a preferred embodiment, the heat exchange tubes of all the inner heat exchange coil tubes have the same inner cross-sectional area.

As a preferred embodiment, the heat exchange tube of the first heat exchange unit has an inner cross-sectional area greater than or equal to that of the heat exchange tube of the second heat exchange unit.

As a preferred embodiment, the first heat exchange unit and the second heat exchange unit are contained in a housing; a spacer for spacing the first heat exchange unit and the second heat exchange unit is also arranged in the shell;

a first flue gas channel is formed between the first heat exchange unit and the partition piece; a second flue gas flow channel is formed between the spacer and the side wall of the shell; the second flue gas flow channel is communicated with the downstream of the first flue gas flow channel; the first heat exchange unit is also provided with a communicated flue gas channel for communicating the first flue gas channel with the combustion chamber.

In a preferred embodiment, the flow direction of the flue gas in the first flue gas flow channel is opposite to the flow direction of the flue gas in the second flue gas flow channel.

In a preferred embodiment, the spacer is a spacer tube sleeved between the first heat exchange unit and the second heat exchange unit.

In a preferred embodiment, the upper end of the second flue gas channel is communicated with the upper end of the first flue gas channel; the lower end of the second flue gas channel is communicated with the smoke exhaust structure.

As a preferred embodiment, the smoke exhausting structure comprises a smoke collecting cavity arranged at the lower end of the shell and a smoke exhaust port communicated with the smoke collecting cavity; a supporting part is arranged in the smoke collecting cavity; the support portion is supported between the top and bottom walls of the smoke collection chamber.

In a preferred embodiment, the area of the smoke discharge port is 0.5 times or more the area of the smoke discharge port at the lower end of the second smoke flow path.

In a preferred embodiment, each of said inner heat exchange coil barrels comprises a plurality of axially stacked heat exchange tube rings; the axial gaps of two adjacent inner heat exchange coil pipe barrels are staggered.

In a preferred embodiment, the axial gap between two axially adjacent heat exchange tube rings is greater than or equal to 1.5 mm.

In a preferred embodiment, the second heat exchange unit is communicated with a water inlet end close to or at the bottom of the shell.

As a preferred embodiment, the housing is provided with a fluid outlet near or at the top of the housing; the fluid output end is communicated with the first heat exchange unit; and the top of the shell is also provided with a communicating pipe which communicates the second heat exchange unit with the first heat exchange unit.

As a preferred embodiment, the spacer partitions the housing to form an inner accommodating space accommodating the first heat exchange unit and an outer accommodating space accommodating the second heat exchange unit; the lower end of the outer containing space is also communicated with a condensed water discharge structure.

As a preferred embodiment, the condensed water drain structure is further communicated with the inner containing space.

As a preferred embodiment, the housing includes a cylindrical main body, and an upper end cover and a lower end cover which are fixedly covered on both ends of the cylindrical main body; the first heat exchange unit and the second heat exchange unit are limited to be positioned between the upper end cover and the lower end cover; and the lower end cover is provided with a first communication hole for communicating the outer containing space with the condensed water discharge structure and a second communication hole for communicating the inner containing space with the condensed water discharge structure.

In a preferred embodiment, the second communication hole is located directly below the first heat exchange unit.

As a preferred embodiment, the lower end cover is provided with a holding groove for holding the lower end of the first heat exchange unit; the second communicating hole leads into the accommodating groove.

A hot water boiler comprising: the heat exchange device according to any one of the above embodiments.

A steam generating apparatus comprising: the heat exchange device according to any one of the above embodiments.

Has the advantages that:

according to the heat exchange device provided by the embodiment of the invention, the second heat exchange unit is sleeved outside the first heat exchange unit, and the first heat exchange unit is spirally formed by the finless heat exchange tube; the second heat exchange unit is spirally formed by the fin heat exchange tubes, so that the first heat exchange unit formed by the fin-free heat exchange tubes is in contact with high-temperature flue gas before the second heat exchange unit formed by the fin heat exchange tubes, and the high-temperature flue gas is cooled by heat exchange with the high-temperature flue gas, the fin heat exchange tubes are prevented from being directly contacted with the high-temperature flue gas at the most upstream to be damaged by the high-temperature flue gas, the use reliability of equipment is improved, the service life of the equipment is ensured, and the maintenance period is prolonged.

According to the heat exchange device provided by one embodiment of the invention, the spacing piece for spacing the first heat exchange unit and the second heat exchange unit is arranged in the shell, and the inner and outer accommodating spaces which are spaced from each other are formed in the shell through the spacing piece, so that a flue gas flow path can be prolonged, the heat exchange effect is improved, the first heat exchange unit and the second heat exchange unit which are sleeved are conveniently arranged, the size of equipment is favorably reduced, and steam is rapidly produced.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a schematic cross-sectional view of a steam generating apparatus provided in accordance with an embodiment of the present invention;

FIG. 2 is a front view of the heat exchange unit of FIG. 1;

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a perspective view of FIG. 2;

FIG. 5 is a sectional view A-A of FIG. 3;

FIG. 6 is a partial schematic view of FIG. 5;

FIG. 7 is a partial schematic view of FIG. 1;

FIG. 8 is a schematic cross-sectional view of the heat exchange unit of FIG. 1;

FIG. 9 is a schematic perspective view of the heat exchange unit of FIG. 1;

FIG. 10 is a schematic view of the smoke evacuation arrangement of FIG. 1;

FIG. 11 is a side view of FIG. 1;

FIG. 12 is a front view of FIG. 10;

FIG. 13 is a schematic sectional view of a heat exchange unit of a hot water boiler according to an embodiment of the present invention;

FIG. 14 is a schematic cross-sectional view of the first heat exchange unit of FIG. 13;

FIG. 15 is an enlarged view of a portion of FIG. 13;

FIG. 16 is a schematic cross-sectional view of the first and second heat exchange units of FIG. 13;

fig. 17 is a front view of fig. 15.

Description of reference numerals: 100. a housing; 101. an upper end cover; 102. a lower end cover; 110. a water inlet end; 120. a fluid output; 130. a fluid output; 140. a fluid input; 150. a communicating pipe; 180. an inner containing space; 190. an outer containment space; 200. a smoke evacuation structure; 201. a smoke outlet; 202. a smoke collection cavity; 203. a condensed water discharge port; 205. a bottom wall; 210. a support portion; 300. a supporting seat; 400. a burner; 500. a fan;

f1, axial; f2, radial;

1. a combustion chamber; 2. a first heat exchange unit; 20. an inner heat exchange coil tube; 21. a first inner heat exchange coil tube; 22. a second inner heat exchange coil tube; 25. a heat exchange tube ring; 3. a second heat exchange unit; 30. an outer heat exchange coil tube; 31. a finned heat exchange tube; 4. a spacer; 5. a first flue gas channel; 6. a second flue gas channel; 61. a smoke outlet; 7. a flue gas channel is communicated; 8. an upper positioning box; 81. an upper accommodating groove; 9. a heat insulation plate; 10. a lower positioning box; 1011. and a lower accommodating groove.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 12, an embodiment of the present invention provides a heat exchange device which is suitable for, but not limited to, a steam generating apparatus such as a steam boiler or a gas-fired hot water apparatus such as a hot water boiler. Wherein the volume of the heat exchange device is below 30L. In the embodiment of the steam generating device, the heat exchanger can rapidly heat the heated medium to more than 130 ℃, for example, the temperature of the input water is 20 ℃, the temperature of the output steam is 180 ℃, and the temperature of the heated medium is 160 ℃.

As shown in fig. 13 to 17, in the embodiment applied to the hot water boiler, the heat exchange device can rapidly raise the temperature of the water flow by more than 30 degrees celsius, for example, the temperature of the input water is 20 degrees celsius, the temperature of the output hot water is 60 degrees, and the temperature is raised by 40 degrees celsius through the heat exchange unit.

In this embodiment, this heat transfer device includes: a housing 100; a first heat exchange unit 2 and a second heat exchange unit 3 located within the housing 100. Specifically, the inner space surrounded by the first heat exchange unit 2 is configured as a combustion chamber 1. The burner 400 is located in the combustion chamber 1 in the housing 100 to perform combustion, and high-temperature flue gas is formed. The second heat exchange unit 3 surrounds the first heat exchange unit 2. The first heat exchange unit 2 and the second heat exchange unit 3 exchange heat with high-temperature flue gas to heat the fluid inside to form steam.

A spacer 4 is arranged between the second heat exchange unit 3 and the first heat exchange unit 2. The second heat exchange unit 3 communicates upstream of the first heat exchange unit 2 in the flow direction of the medium to be heated. First heat exchange unit 2 is closer to burner 400 than second heat exchange unit 3, correspondingly, along the flue gas flow direction, first heat exchange unit 2 is located second heat exchange unit 3 upstream.

As shown in FIG. 1, the combustor 400 is a fully premixed combustor 400. A fan 500 and a premixing device are connected to the upstream of the combustor 400 (for example, to the upper side of the combustor 400). Air and gas are mixed in a desired ratio by a premixing device, and are sent to the combustor 400 by the fan 500 to be ignited in the combustion chamber 1 for combustion.

In the embodiment of the steam generating apparatus, as shown in fig. 1 to 12, the water in the first heat exchange unit 2 is converted from liquid to steam, a steam-water mixing area is formed, and steam is output. Water enters the second heat exchange unit 3 to be preheated, and then enters the first heat exchange unit 2 to be evaporated and overheated, so that water forms water vapor and the water vapor is output. Referring to fig. 13 to 17, in the embodiment of the hot water boiler, cold water firstly enters the second heat exchange unit 3 for preheating, and then enters the first heat exchange unit 2 for further heating, so that the water reaches a target temperature and is output.

In this embodiment, a first flue gas channel 5 is provided between the first heat exchange unit 2 and the spacer 4. A second flue gas flow channel 6 is formed between the spacer 4 and the housing 100. The second flue gas channel 6 is communicated with the downstream of the first flue gas channel 5. The first heat exchange unit 2 is provided with a communicating flue gas channel 7 for communicating the first flue gas channel 5 with the combustion chamber 1. The high-temperature flue gas enters the first flue gas flow channel 5 through the communicating flue gas flow channel 7, flows in the first flue gas flow channel 5, enters the second flue gas flow channel 6, and is finally discharged.

The heat exchange device that this embodiment provided is through being equipped with first flue gas runner 5, second flue gas runner 6 and intercommunication flue gas runner 7, and then promotes the area of contact of flue gas and the heat exchange tube of first heat exchange unit 2 and second heat exchange unit 3, promotes heat exchange efficiency, reaches energy-conserving high-efficient, the high effect of reliability, realizes steam or hydrothermal quick production. Moreover, the heat exchange device can also reduce the volume of the heat exchange device.

In this embodiment, the interior cylindrical cavity of the housing 100. The spacer 4 is a cylindrical spacer plate, and may be a spacer cylinder. The spacing cylinder is of a cylindrical structure. The spacer 4 partitions the inside of the case 100 to form an inner receiving space 180 and an outer receiving space 190. Wherein the first heat exchange unit 2 and the burner 400 are located in the inner receiving space 180, and the second heat exchange unit 3 is located in the outer receiving space 190.

In the outer accommodation space 190, the space outside the second heat exchange unit 3 forms a second flue gas flow passage 6, the upper end of the second flue gas flow passage 6 is a flue gas input end, and the lower end is a flue gas discharge end, so that the flue gas flows from top to bottom on the whole and performs sufficient heat exchange with the second heat exchange unit 3.

The first heat exchange unit 2 is located in the inner accommodating space 180, and an inter-tube gap L2 and an axial gap L1 are formed between the heat exchange tubes, thereby increasing the contact heat exchange area with the flue gas and improving the heat exchange efficiency. The first heat exchange unit 2 and the inner wall of the spacing cylinder are spaced at a certain distance to form a first flue gas flow channel 5.

In other embodiments, the spacer 4 may be a tapered cylinder. The number of the coil pipes of the first heat exchange unit 2 is gradually reduced from top to bottom, the longitudinal section of the first heat exchange unit can be of an inverted cone structure, correspondingly, the number of the coil pipes of the second heat exchange unit 3 is gradually increased from top to bottom, the longitudinal section of the first heat exchange unit can be of a forward cone structure, the two coil pipes are sleeved to form a roughly rectangular section, and correspondingly, the first flue gas channel 5 and the second flue gas channel 6 are parallel inner and outer inclined channels positioned on the inner side and the outer side of the cone.

In this embodiment, the second flue gas flow channel 6 is spaced around the first flue gas flow channel 5. One end of the second flue gas flow channel 6 along the whole flue gas flow direction is communicated with one end of the first flue gas flow channel 5, and the other end of the second flue gas flow channel 6 is a flue gas outlet 61 for outputting the flue gas after heat exchange outwards. Further, the flue gas direction of the first flue gas flow passage 5 and the second flue gas flow passage 6 is substantially parallel to the extending direction (length direction) of the combustion chamber 1.

The heat exchange device of this embodiment can promote the heat transfer area that first heat exchange coil participated in the heat transfer through being equipped with intercommunication flue gas runner 7. In this embodiment, combustion chamber 1 and first flue gas runner 5 are located the inside and outside both sides of first heat exchange unit 2, guarantee that the inside and outside both sides of first heat exchange unit 2 fully contact with the flue gas, guarantee heat exchange efficiency, intercommunication flue gas runner 7 is located the upper and lower (axial F1) both sides of the heat exchange tube of first heat exchange coil, make both sides can fully contact with the flue gas equally about the heat exchange tube of first heat exchange unit 2, increase the heat transfer area of heat transfer device and flue gas, promote heat exchange efficiency, and then need not to increase coil pipe length, be favorable to reducing heat transfer device's volume.

For reducing heat transfer device's volume and promoting the heat transfer effect, the flue gas certainly first flue gas runner 5 flows in the flow direction change more than 150 degrees of second flue gas runner 6, so reduce the flue gas velocity of flow, promote the heat transfer effect of flue gas and heat transfer unit. Preferably, the extending directions of the first flue gas channel 5 and the second flue gas channel 6 are parallel. The flow direction of the flue gas in the first flue gas flow channel 5 is opposite to the flow direction of the flue gas in the second flue gas flow channel 6. The spacer 4 surrounds the first heat exchange unit 2 and the second heat exchange unit 3. The first flue gas flow channel 5 extends along the inner wall surface of the spacer 4. The second flue gas flow channel 6 extends along the outer wall surface of the spacer 4.

In other embodiments, the first flue gas channel 5 and the second flue gas channel 6 may not be parallel. For example, one of the first flue gas channel 5 and the second flue gas channel 6 is a vertical channel, and the other is an oblique channel, or both are oblique channels. The flue gas directions of the first flue gas flow channel 5 and the second flue gas flow channel 6 form a certain included angle, and the communication position of the first flue gas flow channel and the second flue gas flow channel is a flue gas turning position. The flue gas changes flow direction in first

flue gas runner

5 and 6 intercommunication departments of second flue gas runner, avoids the flue gas to flow at the excessive speed, promotes the heat transfer effect to, make 6 intervals of second flue gas runner encircle outside first flue gas runner 5, reduce heat transfer device's volume.

In this embodiment, the burner 400 of the heat exchanger may be a vertical burner 400, or may be a horizontal burner 400. In this embodiment, the burner 400 is a vertical burner 400, which facilitates the positioning and installation of the heat exchange units (the first heat exchange unit 2 and the second heat exchange unit 3) in the casing 100 without the need of supporting and positioning the radial direction F2.

In the present embodiment, the combustion chamber 1 extends in an axial direction F1. The extension direction of the combustion chamber 1 is parallel to the vertical direction. The vertical burner 400 is located in the combustion chamber 1 with the axial direction F1 likewise being vertical or parallel to the vertical direction. The spacer 4 is cylindrical. The spacer 4 may be a spacer tube fixed within the housing 100. The first flue gas flow channel 5 is arranged between the partition 4 and the first heat exchange unit 2 and extends along the axial direction F1. The first flue gas flow channel 5 is located in the flow channel of the straight cylinder structure between the partition 4 and the first heat exchange unit 2. The second flue gas flow channel 6 is arranged between the partition plate and the shell 100 and extends along the axial direction F1. The overall flue gas direction communicating with the flue gas channel 7 flows substantially in the radial direction F2. Preferably, the communicating flue gas flow passage 7 is perpendicular to the overall flue gas direction of the first axial direction F1 flue gas flow passage.

Specifically, the first heat exchange unit 2 and the second heat exchange unit 3 are formed by extending heat exchange tubes in a spiral manner. Wherein the first heat exchange unit 2 comprises at least one inner heat exchange coil barrel 20. The second heat exchange unit 3 comprises at least one outer heat exchange coil tube 30. The innermost inner heat exchange coil cylinder 20 communicates with the other inner heat exchange coil cylinders 20 upstream in the flow direction of the medium to be heated. Inside the shell 100, a plurality of inner heat exchange coil cylinders 20 are connected in series from inside to outside. The single inner heat exchange coil cartridge 20 may be formed by an uninterrupted spiral extension of a heat exchange tube from top to bottom. The inner heat exchange coil tube 20 is a cylindrical (or cylindrical) tube having the same outer diameter and inner diameter from top to bottom. Preferably, first heat exchange unit 2 may include one or two or three inner heat exchange coil barrels 20.

Further, each of the inner heat exchange coil cartridges 20 includes a plurality of rings of heat exchange tubes (spirals) stacked in the axial direction F1. The heat exchange tube ring 25 is not a closed ring, but a spiral structure formed by extending the heat exchange tube by 180 degrees in a spiral manner, and the projection of the spiral structure on a horizontal plane is a closed ring. Wherein, a plurality of heat exchange tube rings 25 are communicated in sequence from top to bottom to form a spiral structure.

As shown in fig. 8 or fig. 14, the communicating flue gas flow passage 7 includes: an axial gap L1 between adjacent two of said inner heat exchange coil loops in axial direction F1 (in axial direction F1). The communicating flue gas flow passage 7 further comprises: and an inter-barrel gap L2 is formed between two adjacent inner heat exchange coil barrels 20 along the radial direction F2 (on the radial direction F2). The inter-barrel gap L2 communicates the axial gap L1 of two adjacent inner heat exchange coil barrels 20.

Further, the projection of the heat exchange tube ring 25, the inner heat exchange coil barrel 20 or the outer heat exchange coil barrel 30 in the horizontal plane is circular, and in other embodiments, the projection of the heat exchange tube ring 25, the inner heat exchange coil barrel 20 or the outer heat exchange coil barrel 30 in the horizontal plane may also be rectangular or in other shapes.

In the present embodiment, the heat exchange tube rings 25 of the first heat exchange unit 2 have a spacing gap (axial gap L1) therebetween. The deformation space is provided for the deformation of the heat exchange tube through the interval gap, and the equipment is prevented from being damaged due to hard contact. Moreover, the communicated flue gas channel 7 which is approximately along the radial direction F2 can be formed by arranging the interval gap, the heat exchange area between the first heat exchange unit 2 and the flue gas is increased, the heat exchange efficiency is improved, the volume of the heat exchange unit is reduced, the volume of the steam generation equipment is maintained below a desired value, the capacity is not easy to exceed the standard, and the energy saver is not required for assistance.

Further, the interval clearance (axial clearance L1) of first heat exchange unit 2 is more than 1.5mm along the length of axial F1, so can avoid blocking up between the pipe, makes things convenient for the flue gas circulation, cooperatees with the fin heat exchange tube 31 of flue gas low reaches simultaneously, guarantees heat exchange efficiency.

In order to have better system reliability and ensure the service life of the equipment, the inner heat exchange surface of the first heat exchange unit 2 surrounding the combustion chamber 1 is a finless heat exchange surface so as to bear the high temperature of high-temperature flue gas. Wherein, the inner heat exchange coil barrel 20 positioned at the innermost side is formed by spirally extending the finless heat exchange tubes along the axial direction F1.

Specifically, the fluid inside the first heat exchange unit 2 is preheated by the second heat exchange unit 3, so that the heat absorption capacity of the first heat exchange unit is reduced, the temperature of the surface of the heat exchange tube is difficult to reduce, if the finned heat exchange tube 31 is easy to damage, and in order to ensure the service life of the equipment, the first heat exchange unit 2 is formed by a finned heat exchange tube.

In this embodiment, at least part (length) of the heat exchange tubes in the first heat exchange unit 2 are finless heat exchange tubes, and at least part of the heat exchange tubes in the second heat exchange unit 3 are finned heat exchange tubes 31, so as to improve the heat exchange efficiency. Further, the heat exchange coil of the first heat exchange unit 2 is made of stainless steel; and the heat exchange coil of the second heat exchange unit 3 is a stainless steel finned tube.

The heat exchange device of this embodiment carries out the heat transfer with the high temperature flue gas before fin heat exchange tube 31 through no fin heat exchange tube, and then the flue gas has been cooled down when flowing to fin heat exchange tube 31, utilizes fin heat exchange tube 31 to carry out abundant heat transfer with flue gas and water, preheats water to avoid fin heat exchange tube 31 to be damaged by the high temperature flue gas, promoted equipment use reliability, guaranteed equipment life, extension maintenance cycle.

The finned heat exchange tube 31 is in contact with the outer wall of the spacer cylinder and the inner wall of the casing 100 in the outer accommodating space 190, and is communicated with the heat exchange tube up and down through gaps between the fins, so that smoke can pass through the heat exchange tube. The finned heat exchange tube 31 may not be in contact with the outer wall of the spacer cylinder and the inner wall of the casing 100. In order to reduce the volume of the heat exchange device, the clearance between the finned heat exchange tube 31 (second heat exchange unit 3) and the outer wall of the spacing cylinder and/or the inner wall of the shell 100 is within 5 mm.

To ensure the heat exchange efficiency, the second heat exchange unit 3 includes a finned coil or a corrugated pipe which is located in the second flue gas flow passage 6 and extends spirally along the axial direction F1. In the present embodiment, the second heat exchange unit 3 is formed by extending spirally a finned heat exchange tube 31.

In this embodiment, an axial spacer is disposed between two adjacent inner heat exchanging coil rings along the axial direction F1, and the uniformity of the axial gap L1 can be ensured by the axial spacer. Wherein, the axial spacing piece can be a spacing bar between two adjacent inner heat exchange coil rings. An axial gap L1 is provided in the inner heat exchange coil tube 20 to extend spirally and uninterruptedly with the heat exchange tube. A plurality of spacer bars are provided in the axial gap L1. The spacing bars can be made of stainless steel materials, and deformation of the spacing bars under high-temperature smoke is avoided.

In order to improve the turbulence of the flue gas and enhance the heat exchange effect, at least some (length or number) of the axial gaps L1 of the adjacent two inner heat exchange coil cylinders 20 are staggered, or some of the axial gaps L1 are staggered. Each of said inner heat exchange coil tubes 20 comprises a plurality of axially stacked heat exchange tube rings 25. The axial gaps L1 of two adjacent inner heat exchange coil barrels 20 are staggered. In order to reduce smoke resistance and ensure heat exchange efficiency, the axial clearance L1 between two heat exchange tube rings 25 which are adjacent in the axial direction is more than 1.5 mm.

As shown in fig. 5 or fig. 14, the arrow shows the flow direction of the flue gas in the communicating flue gas flow channel 7, the axial gap L1 at the upper part of the first inner heat exchange coil barrel 21 is opposite to the heat exchange tubes of the second inner heat exchange coil barrel 22 along the radial direction F2, and the flue gas flowing out of the axial gap L1 of the first inner heat exchange coil barrel 21 collides with the inner side walls of the heat exchange tubes of the second inner heat exchange coil barrel 22 to flow upwards or downwards, then flows out of the axial gap L1 of the second inner heat exchange coil barrel 22 into the first flue gas flow channel 5, and flows upwards along the axial direction F1 along the inner wall of the spacer barrel.

Further, the heated medium flowing areas of the inner heat exchange coils of at least two inner heat exchange coil barrels 20 are different. Wherein, the flow area of the heated medium is the internal cross-sectional area of the heat exchange tube. In this embodiment, in order to improve the operation stability of the device, the heated medium flow area of the inner heat exchange coil cylinder 20 located at the outer side is larger than the heated medium flow area of the inner heat exchange coil cylinder 20 located at the inner side. Compared with the inner heat exchange coil barrel 20 on the inner side, the inner fluid of the inner heat exchange coil barrel 20 on the outer side gradually begins to vaporize to form water vapor, the volume of the inner fluid is increased, and the heated medium flowing area of the inner heat exchange coil barrel 20 on the outer side is larger to adapt to the volume change of the fluid, so that the pipeline resistance is reduced, and the operation stability and reliability of the equipment are improved.

In the embodiment of the steam generating apparatus, of the at least two inner heat exchange coil cylinders 20, the inner cross-sectional area of the heat exchange tube of the inner heat exchange coil cylinder 20 located at the outer side is larger than the inner cross-sectional area of the heat exchange tube of the inner heat exchange coil cylinder 20 located at the inner side. More specifically, in two adjacent inner heat exchange coil cylinders 20, the inner cross-sectional area of the heat exchange tube of the inner heat exchange coil cylinder 20 located on the outer side is 1.1 to 3.1 times the inner cross-sectional area of the heat exchange tube of the inner heat exchange coil cylinder 20 located on the inner side.

In the embodiment of the hot water boiler, the water of the hot water boiler is output as hot water as a whole, considering that the water does not change phase during heating. Thus, in this embodiment, the water flow area of the inner heat exchange coils of at least two of the inner heat exchange coil cartridges 20 is the same. Wherein, the water flow area is the internal cross-sectional area of the heat exchange tube.

In other embodiments, to improve the operation stability of the device, the water flow area of the inner heat exchange coil cylinder 20 located at the outer side may be larger than the water flow area of the inner heat exchange coil cylinder 20 located at the inner side. Compared with the inner heat exchange coil tube 20 on the inner side, the inner heat exchange coil tube 20 on the outer side has higher temperature of the fluid inside and larger volume of the fluid inside, so that the water flowing area of the inner heat exchange coil tube 20 on the outer side is larger to adapt to the volume change of the fluid, the pipeline resistance is reduced, and the operation stability and the reliability of the equipment are improved.

Further, in order to adapt to the change of the volume of the heated fluid, the internal cross-sectional area of the heat exchange tube of the first heat exchange unit 2 is larger than or equal to that of the heat exchange tube of the second heat exchange unit 3.

In this embodiment, the first heat exchange unit 2 includes: two inner heat exchange coil tubes 20 are sleeved with each other. Wherein each of the inner heat exchange coil barrels 20 is formed by spirally extending a finless heat exchange tube along an axial direction F1. The finless heat exchange tube can be a light tube, or a corrugated tube. Preferably, the finned heat exchange tube is of a light pipe structure, so that the fins are prevented from being damaged by high temperature and the service life of equipment is prevented from being influenced.

The two inner heat exchange coil barrels 20 may be a first inner heat exchange coil barrel 21 and a second inner heat exchange coil barrel sleeved outside the first inner heat exchange coil barrel 21. Wherein the flow area of the heated medium of the second inner heat exchange tube (of the heat exchange tube) is larger than that of the heated medium of the first inner heat exchange tube (of the heat exchange tube). As can be seen in fig. 5 and 8, the pipe diameter of the second inner heat exchange tube 22 is larger than that of the first inner heat exchange tube 21 and larger than that of the pipe body of the outer heat exchange coil tube 30. The second inner heat exchange tube 22 has an inner diameter larger than that of the first inner heat exchange tube 21 and larger than that of the outer heat exchange coil tube 30.

In the embodiment of the hot water boiler, as shown in fig. 14, the heat exchange tubes of at least two of the inner heat exchange coil cartridges 20 have the same inner cross-sectional area. Further, the heat exchange tubes of all the inner heat exchange coil barrels 20 have the same inner cross-sectional area. As shown in fig. 16, the heat exchange tubes of the outer heat exchange coil tube 30 have the same inner cross-sectional area as the heat exchange tubes of the inner heat exchange coil tube 20.

In the present embodiment, one end of the first flue gas flow passage 5 in the axial direction F1 is communicated with one end of the second flue gas flow passage 6. The other end of the second flue gas channel 6 is communicated with the smoke exhausting structure 200. As shown in fig. 1, the upper end of the first flue gas channel 5 is in communication with the upper end of the second flue gas channel 6. The lower end of the second flue gas channel 6 is communicated with the smoke exhausting structure 200. The second flue gas flow passage 6 or the flue gas outlet 61 at the lower end of the outer accommodating space 190 is annular and directly leads into the flue gas collecting cavity 202 below the second flue gas flow passage. Meanwhile, the smoke outlet 61 is also a condensed water discharge port 203 of the second smoke flow path 6.

In the embodiment of the steam generating apparatus, the temperature of the fluid in the second heat exchange unit 3 is low, and thus condensed water is easily formed in the outer receiving space 190. The fluid that first heat exchange unit 2 flows into is the fluid after second heat exchange unit 3 preheats to the temperature rise is bigger, exceeds 100 degrees centigrade even, based on the higher temperature of the inside fluid of first heat exchange unit 2, is difficult for forming the comdenstion water in accommodation space 180, and then the lower end cover 102 of accommodation space 180 coverage can not set up the comdenstion water discharge structure in.

As shown in fig. 15 and 17, in the embodiment of the hot water boiler, although the fluid flowing in from the first heat exchange unit 2 is the fluid preheated by the second heat exchange unit 3, the water discharged from the first heat exchange unit 2 of the hot water boiler is still hot water, the temperature of the output water is not more than 100 degrees celsius, usually not more than 70 degrees celsius, and the temperature (relative to the temperature of the flue gas) of the first heat exchange unit 2 in the inner accommodating space 180 is still in a low state, so that the condensed water is also generated, and the condensed water discharge structure is further communicated with the inner accommodating space.

In this embodiment, in order to ensure the heat exchange efficiency, ensure the smoke evacuation effect, and avoid the smoke from being too large to affect the steam generation, the minimum effective smoke flow area of the smoke evacuation structure 200 is greater than or equal to half of the minimum effective smoke flow area of the second smoke flow channel 6.

The lower end of the housing 100 is provided with a smoke evacuation structure 200. The lower end of the smoke evacuation structure 200 is further provided with a support base 400. The steam generating device is supported by the support base 400. The lower end of the second flue gas channel 6 is communicated with the smoke exhausting structure 200. Further, the smoke exhausting structure 200 can also be used as a condensed water discharging structure to collect condensed water in the second smoke flow channel 6 and discharge the condensed water to the outside. Of course, in other embodiments, the heat exchanger may additionally be provided with a condensed water discharging structure, which is communicated with the lower end of the second flue gas channel 6.

In this embodiment, the smoke exhausting structure 200 includes a smoke collecting cavity 202 disposed at the lower end of the casing 100, and a smoke exhausting port 201 communicated with the smoke collecting cavity 202. A support portion 210 is disposed in the smoke collection chamber 202. The support 210 is supported between the top and bottom walls 205 of the smoke collection chamber 202. The smoke collection chamber 202 is an annular chamber surrounding the support portion. The area of the smoke exhaust port 201 is more than 0.5 times of the area of the smoke outlet 61 at the lower end of the second smoke flow channel 6. To facilitate drainage of the condensate, the bottom wall 205 of the smoke collection chamber 202 is an inclined bottom wall.

As shown in fig. 11, the bottom wall 205 of the smoke collection chamber 202 is gradually sloped downward toward the smoke exit 201. A condensed water outlet 203 is also arranged at the position of the bottom wall 205 of the smoke collection cavity 202 close to the smoke outlet 201. Preferably, the condensed water outlet 203 is located at the lowest position of the bottom wall 205 of the smoke collecting cavity 202, so as to facilitate the discharge of the condensed water completely and prevent liquid accumulation.

In this embodiment, the supporting portion 210 may be a supporting column located at a substantially central position of the smoke collection chamber 202. In other embodiments, the supporting portion 210 may also be supporting rods or other supporting structures dispersed at different positions in the smoke collecting cavity 202 to maintain the structural stability of the smoke exhausting structure 200, provide a higher smoke flowing area, facilitate the discharge of smoke from the heat exchanging device, and maintain the stable performance of efficient heat exchange inside the casing 100.

In this embodiment, the housing 100 includes a cylindrical body, and end caps (an upper end cap 101 and a lower end cap 102) fixedly covering both ends of the cylindrical body. The upper and

lower caps

101 and 102 may be fixedly coupled to upper and lower ends of the cylindrical body by flanges. And a heat insulation plate 9 is arranged on the inner side of the end cover. Further, in order to provide a better heat insulation effect, an air spacing layer is arranged between the heat insulation plate 9 and the end cover.

As shown in fig. 4, the housing 100 is provided with a water inlet end 110 near or at the bottom of the housing 100. The water inlet end 110 is communicated with the second heat exchange unit 3. The lower end of the second heat exchange unit 3 is a water inlet end 110. The water inlet end 110 may be a threaded or flanged connection. The housing 100 is provided with a fluid output 120 near or at the top of the housing 100. The fluid output end 120 is communicated with the first heat exchange unit 2. The top of the casing 100 is further provided with a communicating pipe 150 for communicating the second heat exchange unit 3 with the first heat exchange unit 2. Communication pipe 150 is provided on upper end cover 101 of case 100.

The whole flow direction of the water (heated medium) in the second heat exchange unit 3 is from bottom to top, the whole flow direction of the flue gas in the second flue gas flow channel 6 is from top to bottom, and the flow directions of the flue gas and the flue gas are opposite, so that the preheating effect of the second heat exchange unit 3 is improved. The upper end of the second heat exchange unit 3 is a fluid output end 130, and is communicated with a fluid input end 140 at the upper end of the first heat exchange unit 2 through a communicating pipe 150 outside the casing 100. The fluid input 140 at the upper end of first heat exchange unit 2 is the upper end of the innermost inner heat exchange coil barrel 20. The heated medium of the innermost inner heat exchange coil tube 20 (first inner heat exchange coil tube 21) flows from top to bottom as a whole, and is communicated with the second inner heat exchange coil tube 22 at the bottom to flow into the second inner heat exchange coil tube 22. The upper end of the second inner heat exchange coil cylinder 22 has a fluid outlet 120 and extends from the upper end cap 101 to output steam or hot water outwardly.

As shown in fig. 13 to 17, in the embodiment of the hot water boiler, in order to discharge the condensed water in the inner receiving space 180, the lower end cap 102 is provided with a first communication hole (as shown in fig. 2, the smoke outlet 61 is also a first communication hole) communicating the outer receiving space 190 with the condensed water discharge structure, and a second communication hole 15 communicating the inner receiving space 180 with the condensed water discharge structure. As shown in fig. 13, the lower end cap 102 is provided with a receiving groove 1011 (in the figure, the lower receiving groove 1011) for receiving the lower end of the first heat exchange module 2. The second communicating hole 15 opens into the receiving groove 1011.

As shown in fig. 14 and 17, the inner side of the end cap is further provided with accommodating grooves (an upper accommodating groove 81 and a lower accommodating groove 1011). The first heat exchange module 2 and the second heat exchange module 3 are confined between the upper receiving groove 81 and the lower receiving groove 1011. The upper receiving groove 81 and the lower receiving groove 1011 are fixedly installed on the heat insulating plate 9. The housing grooves (81, 1011) have an annular U-shaped groove structure. The ends of the first heat exchange module 2 and the second heat exchange module 3 can extend into the upper receiving groove 81 and the lower receiving groove 1011 of the receiving groove. The second communication hole 15 passes through the lower end cap and communicates the smoke collecting chamber 202 with the receiving groove 1011. The plurality of second communication holes 15 communicate with the bottom of the lower receiving groove 1011 and are uniformly arranged in the circumferential direction. Of course, the at least one second communication hole 15 may communicate with the lowest position of the lower receiving groove 1011.

In this embodiment, the lower end cover 102 is provided with a receiving groove 1011 for receiving the lower end of the first heat exchange unit 2. The second communicating hole 15 opens into the receiving groove 1011. Specifically, the inner sides of the end covers 101 and 102 are further provided with positioning boxes (an upper positioning box 8 and a lower positioning box 10). The positioning box is fixed on the inner side of the end cover. The

positioning cartridges

8, 10 provide

accommodating grooves

81, 1011. The upper positioning box 8 provides the upper receiving groove 81, and the lower positioning box 10 provides the lower receiving groove 1011.

The first heat exchange unit 2 and the second heat exchange unit 3 are confined between an upper positioning box 8 and a lower positioning box 10. The upper positioning box 8 and the lower positioning box 10 are fixedly arranged on the heat insulation plate 9. The positioning boxes (8, 10) are in annular U-shaped groove structures. The ends of the first heat exchange unit 2 and the second heat exchange unit 3 may extend into the upper receiving groove 81 and the lower receiving groove 1011 of the positioning box.

In this embodiment, a supporting structure for supporting the first heat exchanging unit 2 is further disposed in the casing 100. The support structure may be a support plate provided on the lower positioning box 10. The supporting plate can be spirally extended (along with the heat exchange tube at the lowest position) to be arranged on the inner wall of the lower positioning box 10, so that the lowest heat exchange tube is supported, the heat exchange tube at the lowest position is prevented from being suspended, the heat exchange unit is prevented from deforming, and the heat exchange effect is influenced. The lower end of the first heat exchange unit 2 is seated in the lower positioning box 10, and the inner and outer sides of the lower end of the first heat exchange unit 2 can be attached to the inner wall of the lower positioning box 10, thereby restricting the first heat exchange unit 2 in the radial direction F2.

With continuing reference to fig. 1-12, in yet another embodiment of the present invention, a steam generating apparatus is provided, comprising: a housing 100; a first heat exchange unit 2; a second heat exchange unit 3 surrounding said first heat exchange unit 2.

In the present embodiment, the inner space surrounded by the first heat exchange unit 2 is configured as a combustion chamber 1 for combustion by a burner 400. The second heat exchange unit 3 communicates upstream of the first heat exchange unit 1 in the flow direction of the medium to be heated. Further, a spacer 4 is disposed in the housing 100. The spacer 4 partitions the inside of the case 100 to form an inner receiving space 180 for receiving the first heat exchange unit 2 and an outer receiving space 190 for receiving the second heat exchange unit 3. The outer receiving space 190 communicates with the inner receiving space 180. The outer receiving space 190 communicates downstream of the inner receiving space 180 in the flow direction of the smoke.

The first heat exchange unit, the second heat exchange unit and the spacer can adopt the first heat exchange unit and the second heat exchange unit of the heat exchange device of the above embodiment. Preferably, the steam generating device can be provided with the heat exchange device in the embodiment. The can burner 400 is located in the combustion chamber 1 defined by the heat exchanging means.

The steam generating equipment that this embodiment provided prolongs flue gas flow path with inside and outside looks alternate space of first heat exchange unit and second heat exchange unit with the inside formation of casing through setting up in the casing, promotes the heat transfer effect to conveniently arrange first heat exchange unit and the second heat exchange unit of establishing in the cover, be favorable to reducing equipment volume, quick output steam.

Referring to fig. 13 to 17, according to another embodiment of the present invention, there is provided a hot water boiler, including: a heat exchange apparatus as described in any one of the preceding embodiments.

Any numerical value recited herein includes all values from the lower value to the upper value, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. For example, if it is stated that the number of a component or a value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, it is intended that equivalents such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also expressly enumerated in this specification. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are explicitly recited in the specification in a similar manner are to be considered.

Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. The use of "about" or "approximately" with a range applies to both endpoints of the range. Thus, "about 20 to about 30" is intended to cover "about 20 to about 30", including at least the endpoints specified.

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, or steps herein also contemplates embodiments that consist essentially of such elements, components, or steps. By using the term "may" herein, it is intended to indicate that any of the described attributes that "may" include are optional.

A plurality of elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, component or step is not intended to foreclose other elements, ingredients, components or steps.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the inventors be construed as having contemplated such subject matter as being part of the disclosed subject matter.

Claims

1. A heat exchange device, comprising: the heat exchanger comprises a first heat exchange unit and a second heat exchange unit surrounding the first heat exchange unit; the inner space surrounded by the first heat exchange unit is configured as a combustion chamber; wherein the second heat exchange unit is communicated with the upstream of the first heat exchange unit along the flow direction of the heated medium; the first heat exchange unit is formed by spirally forming a finless heat exchange tube; the second heat exchange unit is spirally formed by fin heat exchange tubes.

2. The heat exchange device according to claim 1, wherein the first heat exchange unit comprises one or two or three inner heat exchange coil tubes formed by spirally extending heat exchange tubes.

3. The heat exchange device of claim 1, wherein the first heat exchange unit comprises two or three inner heat exchange coil tubes which are sleeved; wherein, along the flow direction of the heated medium, the inner heat exchange coil barrel positioned at the innermost side is communicated with the upstream of other inner heat exchange coil barrels.

4. The heat exchange device according to claim 2, wherein, of the at least two inner heat exchange coil pipes, the heat exchange pipe of the inner heat exchange coil pipe positioned on the outer side has a larger inner cross-sectional area than the heat exchange pipe of the inner heat exchange coil pipe positioned on the inner side.

5. The heat exchange device according to claim 4, wherein, of the adjacent two inner heat exchange coil barrels, the heat exchange tube of the inner heat exchange coil barrel positioned on the outer side has an inner cross-sectional area 1.1 to 3.1 times as large as that of the inner heat exchange tube of the inner heat exchange coil barrel positioned on the inner side.

6. The heat exchange device of claim 2 wherein the heat exchange tubes of at least two of the inner heat exchange coil tubes are of equal internal cross-sectional area.

7. The heat exchange device of claim 6 wherein the heat exchange tubes of all of the inner heat exchange coil tubes are of equal internal cross-sectional area.

8. The heat exchange device of claim 1, wherein the heat exchange tube of the first heat exchange unit has an inner cross-sectional area greater than or equal to an inner cross-sectional area of the heat exchange tube of the second heat exchange unit.

9. The heat exchange device of claim 1, wherein the first heat exchange unit and the second heat exchange unit are contained within a housing; a spacer for spacing the first heat exchange unit and the second heat exchange unit is also arranged in the shell;

10. The heat exchange apparatus of claim 9 wherein the direction of flow of flue gas in the first flue gas flow path is opposite to the direction of flow of flue gas in the second flue gas flow path.

11. The heat exchange device of claim 9 wherein the spacer is a spacer sleeve that fits between the first heat exchange unit and the second heat exchange unit.

12. The heat exchange apparatus of claim 9 wherein the upper end of the second flue gas channel is in communication with the upper end of the first flue gas channel; the lower end of the second flue gas channel is communicated with the smoke exhaust structure.

13. The heat exchange device according to claim 12, wherein the smoke exhaust structure comprises a smoke collection chamber arranged at the lower end of the shell and a smoke exhaust communicated with the smoke collection chamber; a supporting part is arranged in the smoke collecting cavity; the support portion is supported between the top and bottom walls of the smoke collection chamber.

14. The heat exchange apparatus of claim 13 wherein the area of the smoke outlet is greater than 0.5 times the area of the smoke outlet at the lower end of the second flue gas flow path.

15. The heat exchange unit of claim 2 wherein each of said inner heat exchange coil barrels comprises a plurality of axially stacked heat exchange tube rings; the axial gaps of two adjacent inner heat exchange coil pipe barrels are staggered.

16. The heat exchange device of claim 2 wherein the axial gap between two axially adjacent heat exchange tube rings is greater than 1.5 mm.

17. The heat exchange device of claim 9, wherein the second heat exchange unit is connected to a water inlet end near or at the bottom of the shell.

18. The heat exchange device of claim 17 wherein the housing is provided with a fluid output near or at the top of the housing; the fluid output end is communicated with the first heat exchange unit; and the top of the shell is also provided with a communicating pipe which communicates the second heat exchange unit with the first heat exchange unit.

19. The heat exchange device of claim 9 wherein the spacer spaces the housing to form an inner receiving space to receive the first heat exchange unit and an outer receiving space to receive the second heat exchange unit; the lower end of the outer containing space is also communicated with a condensed water discharge structure.

20. The heat exchange device according to claim 19, wherein the condensed water drain structure is further communicated with the inner accommodating space.

21. The heat exchange device of claim 20, wherein the housing comprises a cylindrical body, and an upper end cover and a lower end cover which are fixedly covered at two ends of the cylindrical body; the first heat exchange unit and the second heat exchange unit are limited to be positioned between the upper end cover and the lower end cover; and the lower end cover is provided with a first communication hole for communicating the outer containing space with the condensed water discharge structure and a second communication hole for communicating the inner containing space with the condensed water discharge structure.

22. The heat exchange device according to claim 21, wherein the second communication hole is located directly below the first heat exchange unit.

23. The heat exchange device of claim 21, wherein the lower end cap is provided with a receiving groove for receiving the lower end of the first heat exchange unit; the second communicating hole leads into the accommodating groove.

24. A hot water boiler, comprising: the heat exchange device of any one of claims 1 to 23.

25. A steam generating apparatus, comprising: the heat exchange device of any one of claims 1 to 23.