CN211503247U - Rectangular cross section long circular double-coil gas condensation hot water boiler structure - Google Patents

Abstract

The utility model discloses a two coil pipe gas condensation hot-water boiler structures of rectangle cross section long circle, including shell, the combustor that has the long circle cross section burning head, inside and outside double-deck long circle coil pipe, import and export collection case, middle collection case and front and back apron etc.. The boiler body consists of a front cover plate, a rear cover plate, a long circular double-coil pipe and a shell. The front cover plate is used for fixing the burner, the burning head with the long circular cross section is matched with the long circular coil pipe to ensure that smoke is uniformly distributed along the circumference, the front cover plate and the rear cover plate form a closed space to force the smoke to continuously flow through a side gap of the double coil pipes, the gap of the outer coil pipe is smaller than that of the inner layer, so that the smoke is deeply cooled and condensed, the smoke exhaust temperature can be reduced to below 45 ℃, and the thermal efficiency of the boiler can reach 103% under the rated load. Boiler return water enters the outer-layer coil pipe from the inlet header, is heated and then is further heated by the inner-layer coil pipe led in by the middle header, and hot water is supplied to a user from the inner-layer outlet header. The long circular double-coil pipe has compact structure, heat exchange enhancement, small deformation and long service life.

Description

Rectangular cross section long circular double-coil gas condensation hot water boiler structure

Technical Field

The utility model relates to an reinforce heat transfer energy-efficient technical field, specifically be a heat transfer coil adopts the gas condensation boiler structure of inside and outside double-deck long circular structural design.

Background

Natural gas is widely used as a clean and environment-friendly high-quality energy source, and a gas condensing boiler is also a future development trend as an energy-saving and environment-friendly product. The traditional coil pipe boiler is characterized in that a steel plate is rolled and welded into a round pipe, the round pipe is subjected to cold machining and extrusion deformation to form a flat pipe with an oblong cross section, then a straight flat pipe is machined and bent into a round coil pipe, finally stress relief annealing is carried out to obtain a finished round coil pipe unit, and a welding longitudinal seam exists on the coil pipe, so that corrosion leakage risks exist; the cold processing deformation in the coil pipe processing is large, and residual stress and lattice defects exist; the processing technology is complicated, the yield is low, and the production cost is high. The traditional coil pipe is easy to generate intergranular corrosion cracking in operation, so that the service life of a product is short.

Disclosure of Invention

In order to promote coil pipe gas condensation boiler's development, to the problem that exists among the prior art, the utility model provides a two coil pipe gas condensation hot-water boiler structures of rectangle cross section long circle, the two coil pipe structures of long circle are compact, reinforce the heat transfer, and the deflection is little, longe-lived. The method has the characteristics of environmental protection, greenness, water saving and the like, and achieves the purposes of saving energy, reducing emission and reducing cost.

The utility model discloses a realize through following technical scheme:

a rectangular cross section long circular double-coil gas condensation hot water boiler structure sequentially comprises a shell 1, an outer coil 2, an inner coil 12 and a long circular cross section burner 15 from outside to inside, a front cover plate 17 and a rear cover plate 18 which are arranged at the front ends of the inner coil 12 and the outer coil 2, an outer inlet header 7 and an outer outlet header 8 which are arranged at the same side or different sides of the outer coil 2, an inner inlet header 10 and an inner outlet header 11 which are arranged at the same side or different sides of the inner coil 12, and a middle header 9 which is arranged between the outer coil 2 and the shell 1; a condensing pipe 16 is arranged at the bottom of the shell 1; the combustion head 15 with the long circular cross section is arranged in the center of a hearth formed by the inner-layer coil pipe 12, the front cover plate 17 and the rear cover plate 18; the boiler adopts the design of inside and outside double-deck coil pipe, and the internal face of inlayer coil pipe 12 forms confined furnace with front shroud 17 and back shroud 18, absorbs flue gas radiant heat and convection heat, and inlayer coil pipe 12 and outer coil pipe 2 degree of depth cooling condensation flue gas, and the flue gas passes through double-deck coil pipe heat transfer successively, flows to exhaust port 4 along casing nearly wall flue gas passageway 5 to discharge the comdenstion water through condenser pipe 16.

A front cover plate 17 and a rear cover plate 18 which are internally coated with refractory materials are correspondingly arranged between the front and the rear of the inner-layer coil pipe 12 and the outer-layer coil pipe 2 and the shell 1 respectively, the front cover plate 17 is used for fixing a burner, the front cover plate 17 and the rear cover plate 18 form a closed space to strengthen the air tightness of heat exchange of the coil pipes, and high-temperature flue gas generated by the burner is forced to continuously flow through the side gaps of the double coil pipes; and a fire observation hole, an ignition needle and a fire detection needle preformed hole are arranged on the front cover plate 17 and are used for observing and adjusting the combustion state and feeding back in time.

The inner-layer coil pipe 12 and the outer-layer coil pipe 2 are both long circular coil pipes, and according to the capacity and the actual situation of the hot water furnace, the length of a straight section of the inner-layer coil pipe 12 is 300-1800 mm, and the length of a semicircular section of the inner-layer coil pipe 12 is 130-780 mm; the length of the straight section of the outer-layer coil pipe 2 is 1-1.2 times of that of the inner-layer coil pipe, and the length of the semicircular section of the outer-layer coil pipe 2 is 1.2-1.8 times of that of the semicircular section of the inner-layer coil pipe; the height of the cross section of the long circular coil pipe is 15-30 mm, and the effective width is 30-120 mm; the inner layer coil pipe 12 and the outer layer coil pipe 2 are stacked together front and back, and the gaps between the coil pipes can be positioned by comb teeth, positioning gaskets 14 or bulge protrusions.

The combustion head 15 with the long circular cross section is arranged in the center of the hearth and matched with the long circular coil pipe to ensure that smoke is uniformly distributed along the circumference, 50-1000 mm is reserved between the outer surface of the combustion head 15 with the long circular cross section and the inner surface of the inner-layer coil pipe 12 to prevent carbon deposition caused by incomplete combustion due to the fact that flame directly erodes the inner surface of the long circular inner-layer coil pipe 12, the inlet end of the combustion head 15 with the long circular cross section is provided with a refractory material section to ensure that a flame surface of the combustion head 15 with the long circular cross section is positioned in the center of the hearth, and the length of the combustion head 15; the length of the straight section of the cross section of the combustion head 15 with the long circular cross section is 70-420 mm, and the length of the semi-circle section of the cross section of the combustion head 15 with the long circular cross section is 30-180 mm.

The inner layer coil pipe 12 and the outer layer coil pipe 2 are provided with 1-50 coil pipe units according to the difference of the capacity of the hot water furnace, the number of pipe turns of each coil pipe unit is 1-50, the gap of the inner layer coil pipe is 0.5-2.0 mm, and the gap of the outer layer coil pipe is 0.4-2.0 mm. The inner layer coil pipe 12 and the outer layer coil pipe 2 are welded with two ends of the coil pipe by adopting 90-degree elbows to form a water inlet and a water outlet which are positioned on the same plane.

The inner-layer coil pipe 12 and the outer-layer coil pipe 2 are both provided with inlet and outlet header tanks, an inner-layer inlet header tank 10 and an inner-layer outlet header tank 11 of the inner-layer coil pipe 12 are arranged between the inner-layer coil pipe 12 and the outer-layer coil pipe 2, an outer-layer inlet header tank 7 and an outer-layer outlet header tank 8 of the outer-layer coil pipe 2 are arranged between the outer-layer coil pipe 2 and the shell 1, the outer-layer outlet header tank 8 of the outer-layer coil pipe 2 is connected with the inner-layer inlet header tank 10 of the inner-layer coil pipe 12 through a middle header tank 9, and the middle header tank 9 is arranged between; boiler working medium is distributed to all outer-layer coil pipes 2 from an outer-layer inlet header 7, enters an outer-layer outlet header 8 after the outer-layer coil pipes 2 absorb smoke heat, is guided into an inner-layer inlet header 10 through a middle header 9, is redistributed into inner-layer coil pipes 12 to absorb smoke radiation heat and convection heat, and finally hot water produced from an inner-layer outlet header 11 is supplied to a user; wherein, the flow velocity of the boiler working medium in the inner layer coil 12 is not lower than 0.5m/s, the flow velocity of the outer layer coil 2 is not lower than 0.3m/s, and an exhaust valve is arranged on the top of the outer layer outlet header (8) or the outlet pipe.

The inner layer coil pipe 12 and the outer layer coil pipe 2 are respectively provided with 4 to 24 pull support rods 6 for supporting the coil pipes and fixedly pulling the coil pipes, and the pull support rods 6 are fixed on an outer bracket of the boiler.

The shell is made of plastic or butyl rubber, the bottom of the shell is provided with a condensing pipe 16, the smoke outlet 4 is arranged at the tail of the boiler or at the upper side of the boiler shell, and smoke subjected to heat exchange through the outer-layer coil pipe 2 flows to the smoke outlet 4 along the shell wall-near channel 5.

An annular guide plate 19-1 is arranged between the outer-layer coil 2 and the shell 1 to wrap the outer-layer coil 2, a front cover plate 17 and a rear cover plate 18, and the rear end of the annular guide plate 19-1 is provided with an oblong orifice with the same cross section as that of the combustion head 15 with the oblong cross section. Under the action of the annular guide plate 19-1, the smoke absorbs heat and heats up in the process of flushing the front cover plate and the rear cover plate, the relative humidity of the discharged smoke is reduced, and white smoke plume is eliminated in part of time; when the smoke outlet 4 is arranged on the upper side of the shell, an arched guide plate 19-2 is arranged at a position 100-200 mm below the smoke outlet, the arched guide plate 19-2 is fixed by a tension support rod 6, and the chord length of the arched guide plate 19-2 is slightly larger than the semi-circle segment length of the outer-layer coil pipe 2, so that the smoke flow is prevented from directly passing through the smoke outlet, the smoke heat transfer flow is increased, and the heat transfer effect is greatly improved.

The rear end of the outer-layer coil pipe 2 is sequentially provided with an outer-layer annular inlet header 20 and an outer-layer annular outlet header 21, the outer-layer annular inlet header 20 and the outer-layer annular outlet header 21 are provided with corresponding inlet and outlet annular pipe bundles 24 according to the number of coil pipe units of the outer-layer coil pipe 2, and each pair of annular pipe bundles 24 comprises an annular inlet water pipe bundle and an annular return water pipe bundle and is responsible for inlet and return water of each coil pipe unit; for convenient arrangement, the size of the outer annular outlet header 21 is larger than that of the outer annular inlet header 20, an inlet 22 of the outer annular inlet header is arranged above the outer annular inlet header 20, and an outlet 23 of the outer annular outlet header is arranged below the outer annular outlet header 21; boiler working media enter from an outer-layer annular inlet header inlet 22, are distributed to each annular water inlet pipe bundle under the action of gravity, enter the outer-layer coil pipe 2 to absorb heat, then enter respective annular water return pipe bundles, return to the outer-layer annular outlet header 21, enter an inner-layer annular inlet header inlet through an outer-layer annular outlet header outlet 23, and perform the same water return process on the inner-layer coil pipe 12; working medium enters the coil pipe for heat exchange from the annular water inlet pipe bundle and flows out of the coil pipe from the annular water return pipe bundle and returns to the outlet header; due to the distributed arrangement of the annular tube bundles, the adoption of smaller tube bundle diameters is allowed, so that the heat transfer process tends to be mild, and a higher heat transfer coefficient is obtained.

Compared with the prior art, the utility model discloses following profitable technological effect has:

the utility model discloses choose for use 2 180 degrees semicircle sections of the discontinuous bending of rectangular cross section stainless steel finished product pipe blank of steel pipe factory production and 2 straight sections to make the long circle coil pipe, show to reduce the pipe deformation rate that is greater than 180 degrees circular coil pipe bending forming to make the straight section of long circle coil pipe have moulding deformation hardly, and the circular arc section of long circle only through the deformation of 180 degrees 2 times. The utility model discloses a deformation rate of long circle double coil pipe is minimum among all circular coil pipes in the existing market, has the ability that the distortion of best prevention lattice deformation causes intergranular fracture, belongs to the international initiative technique, and the coil pipe structure that has thoroughly solved stainless steel coil pipe hot-water boiler is repeated many times and is out of shape the rate and too big easily arouses the worldwide difficult problem that the lattice distortion leads to intergranular fracture, has established the stability structure basis for the maximization of stainless steel coil pipe hot-water boiler moreover.

The utility model discloses a two coil pipe gas condensation boiler of long circle of rectangular cross section uses long circle cross section combustor, advances return water collection box, long circle inlayer coil pipe and long circle outer coil pipe as the main part, and the effective heat transfer area of boiler can be increased to two coil pipe structures, and the high efficiency absorbs the vapor latent heat in discharging fume, can make the exhaust gas temperature reduce 26 ℃ -45 ℃, and thermal efficiency is promoted to 103%, and is higher even.

The utility model discloses a rectangular cross section's two coil pipe gas condensation boiler's of long circle inlayer coil pipe internal face and front and back apron form radiation confined furnace, match long circle cross section's full premix combustor, and the combustion head entrance point sets up the flame face of the refractory material section of suitable length in order to ensure the combustion head in the furnace center to realize flue gas evenly distributed, avoid the too high export smoke temperature that leads to of local flue gas velocity of flow to rise.

The utility model discloses a rectangular cross section's long circular double coil pipe gas condensation boiler's outer coil pipe clearance is less than inlayer coil pipe clearance, and degree of depth cooling condensation flue gas increases the heat convection coefficient of outer coil pipe, has promoted the thermal efficiency of boiler, reduces the gas use amount, also can absorb the partial harmful substance in the flue gas simultaneously.

The utility model discloses a rectangular cross section's two coil pipe gas condensation hot water boiler's of long circle coil pipe's mould size compares the circular coil pipe of isopower much littleer, is the must way of the way that realizes the coil pipe boiler maximization, and the mould size can be adjusted according to hot-water furnace capacity and long circle coil pipe size, can reduce cost, resources are saved. The oblong configuration can significantly reduce the boiler width compared to the circular configuration.

The utility model discloses a two coil pipe gas condensation boiler of long circle of rectangular cross section rationally sets up the return water loop: boiler working medium is distributed to all outer coil pipe units from an outer layer inlet header, enters an outer layer outlet header after the outer layer coil pipe absorbs smoke heat, enters an inner layer inlet header through a middle header, is redistributed to an inner layer coil pipe to absorb smoke radiant heat and convection heat, and finally hot water is produced from the inner layer outlet header to be supplied to users. The condensed water is discharged out of the system through the condensing pipe and can be recycled or used as process water of other boilers.

The utility model discloses a rectangular cross section's long circle double coil pipe gas condensation boiler's exhaust port is when being located the casing upside, the apron can not lay refractory material around, set up the outer coil pipe of cyclic annular guide plate parcel and lap around and between outer coil pipe and shell, cyclic annular guide plate rear end is provided with the long circle drill way the same with long circle burning head cross section, under the effect of cyclic annular guide plate, the flue gas is washing away the in-process heat absorption of front and back apron and heaies up, reduces the relative humidity of discharging fume, white smoke plume is eliminated to the part time.

The utility model discloses a rectangular cross section's long circle double coil pipe gas condensation boiler can set up the exhaust port in the casing upside, sets up an arch guide plate in exhaust port below 100mm ~ 200mm department, arch guide plate thickness 10mm ~ 20mm, and the chord length of arch guide plate is a bit bigger than the semicircle segment length of outer coil pipe, can hinder the direct exhaust port of flue gas flow, increases flue gas heat transfer flow, improves heat transfer effect by a wide margin.

The utility model discloses a long circular double coil pipe gas condensation boiler of rectangle cross section adopts the water system design of annular collection case. Each pair of annular pipe bundles comprises a water inlet pipe bundle and a water return pipe bundle, and the water inlet pipe bundle and the water return pipe bundle are responsible for water inlet and return of each coil pipe unit. The distributed arrangement of the tube bundles reduces the tube diameters of the tube bundles, can effectively reduce the local uneven heat transfer caused by the concentrated arrangement of the header, leads the heat transfer process to tend to be mild, enhances the reliability and achieves higher heat transfer coefficient.

Drawings

Fig. 1 is a cross-sectional view of the overall structure according to the embodiment of the present invention.

Figure 2a is an axonometric view of the inner coil according to an embodiment of the present invention.

Fig. 2b is a front view of the inner coil according to the embodiment of the present invention.

Fig. 3a, fig. 3b and fig. 3c are schematic diagrams of the oblong coil pipe with rectangular, concave rectangular and oblong cross sections according to the embodiment of the present invention.

Fig. 4 is a schematic structural view of a burner with a long circular cross section according to an embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of an embodiment of the present invention.

Fig. 6 is a schematic view of the structure of the outer layer outlet header, the middle header and the inner layer inlet header of the embodiment of the present invention.

Fig. 7 is a schematic view of the structure of the outer inlet header of the embodiment of the present invention.

Fig. 8 is a schematic view of a structure of a housing with a smoke outlet for smoke abatement according to an embodiment of the present invention.

Fig. 9 is a schematic view of the position of the arched deflector according to the embodiment of the present invention.

Fig. 10 is a schematic view of an annular header structure according to an embodiment of the present invention.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

The utility model discloses a two coil pipe gas condensation hot-water boiler of rectangle cross section long circle compact structure, reinforce the heat transfer, the deflection is little, and is longe-lived. The method has the characteristics of environmental protection, greenness, water saving and the like, and achieves the purposes of saving energy, reducing emission and reducing cost.

Specifically, as shown in fig. 1, the utility model discloses two coil pipe gas condensation hot water boiler of rectangle cross section long circle, which comprises a housing 1, outer coil pipe 2, outer coil pipe clearance 3, exhaust port 4, nearly wall flue gas passageway 5, bracing piece 6, outer import collection case 7, outer export collection case 8, middle collection case 9, inlayer import collection case 10, inlayer export collection case 11, inlayer coil pipe 12, inlayer coil pipe clearance 13, locating washer 14, long circle cross section burner 15, condenser pipe 16, front shroud 17, back shroud 18, cyclic annular guide plate 19-1, arch guide plate 19-2, outer annular import collection case 20, outer annular export collection case 21, outer annular import collection case entry 22, outer annular export collection case export 23 and annular export tube bank 24. Flue gas exhausted by a combustion head 15 with a long circular cross section in the long circular double-coil gas condensation hot-water boiler with the rectangular cross section flows through an inner-layer coil pipe gap 13 formed by an inner-layer coil pipe 12, and absorbs radiant heat and convection heat, the flue gas flows in the inner-layer coil pipe gap 13, and the temperature of a flue gas inlet of an outer-layer coil pipe 2 is greatly reduced; the outer coil pipe 2 that flows through afterwards carries out two return strokes degree of depth cooling condensation flue gas, and the flue gas temperature is showing and is reducing, and outer coil pipe clearance 3 is less than inlayer coil pipe clearance 13, strengthens the convection current and the condensation heat transfer of coil pipe and flue gas, and the cooling condensation ability and the heat transfer coefficient of boiler all obtain the reinforcing, have promoted the thermal efficiency of boiler, reduce the gas use amount, also can dilute the harmful substance in the flue gas simultaneously. The combustion head 15 with the oblong cross section is a full-premix combustor with the oblong cross section, the long-circle coil pipe is matched to ensure that smoke is evenly distributed along the circumference, low-calorific-value gas is easy to combust, less gas is incompletely combusted, and gas resources are efficiently utilized. The flue gas exchanges heat through the inner and outer double-layer coil pipes in sequence, flows along the flue gas channel 5 near the wall surface of the shell and is discharged into the smoke outlet 4, and condensed water generated by heat exchange is discharged out of the boiler through the condensing pipe 16 and can be recycled or used as process water of other boilers. The outer-layer inlet header 7 distributes boiler working media to all coil units of the outer-layer coil 2, the working media heated by the coil units of the outer-layer coil 2 are distributed to all coil units of the inner-layer coil 12 through the middle header 9, and the working media generate hot water to be supplied to users through the inner-layer outlet header 11 after heat exchange of the coil units of the inner-layer coil 12, so that a complete water system loop is formed.

As shown in fig. 2 and fig. 3a, 3b and 3c, the inner and outer double-layer coils are both oblong coils. According to the capacity and the actual situation of the hot water furnace, the length of the straight section of the inner layer coil pipe 12 can be 300-1800 mm, and the length of the semicircular section can be 130-780 mm; the length of the straight section of the outer-layer coil 2 can be 1-1.2 times of that of the straight section of the inner-layer coil 12, and the length of the semicircular section of the outer-layer coil 2 is 1.2-1.8 times of that of the semicircular section of the inner-layer coil 12; the height of the cross section of the long circular coil pipe can be 15 mm-30 mm, and the effective width can be 30 mm-120 mm. The inner layer coil pipe 12 and the outer layer coil pipe 2 are provided with 1-50 coil pipe units according to the difference of the capacity of the water heater, the number of coil pipe turns of each coil pipe unit can be set to 1-50 turns, the inner layer coil pipe gap 13 can be set to 0.5 mm-2.0 mm, and the outer layer coil pipe can be set to use a smaller coil pipe gap of 0.4 mm-2.0 mm. The inner and outer double-layer coil pipe units are welded with two ends of the coil pipe by adopting 90-degree elbows to form water inlets and water outlets on the same plane. The coil units are stacked together front and back, and the gaps between the coils are positioned by positioning gaskets 14. The oblong configuration can significantly reduce the boiler width compared to the circular configuration. After the heat exchange of the flue gas is carried out by the double-layer coil pipe, the temperature of the discharged flue gas can be reduced to 26-43 ℃, and the heat efficiency of the hot water boiler is improved to 103-109%.

As shown in fig. 4 and 5, the combustion head 15 with the oblong cross section is arranged in the center of the furnace, the oblong coil pipe is matched to ensure that the smoke is uniformly distributed along the circumference, reasonable flame size (50-1000 mm) is reserved between the outer surface of the combustion head 15 with the inner surface of the inner-layer coil pipe 12 to prevent the flame from directly washing the inner surface of the oblong inner-layer coil pipe 12 to cause incomplete combustion and carbon deposition, and the inlet end of the combustion head 15 with the oblong cross section is provided with a refractory material section with proper length to ensure that the flame surface of the combustion head is positioned in the center of the furnace, so that the uniform distribution of the smoke is realized, and the increase of the outlet smoke temperature caused by overhigh. The length of the combustion head accounts for 20-100% of the length of the hearth. The length of the straight section of the cross section of the burning head 15 with the oblong cross section can be 70-420 mm, and the length of the semicircular section of the cross section of the burning head with the oblong cross section can be 30-180 mm. A front cover plate 17 and a rear cover plate 18 which are internally coated with refractory materials are correspondingly arranged between the front and the rear of the long circular coil and the shell respectively, the burner is fixed on the front cover plate 17, the front cover plate 17 and the rear cover plate 18 form a closed space to enhance the air tightness of heat exchange of the coil, and high-temperature flue gas generated by the burner is forced to continuously flow through the side gaps of the double coils. The front cover plate 17 is provided with a fire observation hole, an ignition needle and a fire detection needle preformed hole for observing and adjusting the combustion state. Flue gas generated by combustion flows through the inner-layer coil pipe gap 13 formed by the inner-layer coil pipe 12, and absorbs radiant heat and convection heat, so that the temperature at the flue gas inlet of the outer-layer coil pipe 2 is greatly reduced; and then the flue gas is condensed and cooled by two return strokes through the outer-layer coil pipe 2, the cooling and condensing capacity and the heat exchange coefficient of the boiler are enhanced, the heat efficiency of the boiler is improved, the use amount of fuel gas is reduced, and meanwhile, harmful substances in the flue gas can also be diluted.

As shown in fig. 6 and 7, the inner layer coil pipe 12 and the outer layer coil pipe 2 are both provided with an inlet and outlet header, the inlet and outlet header of the inner layer coil pipe 12 is arranged between the inner layer coil pipe and the outer layer coil pipe, the inlet and outlet header of the outer layer coil pipe is arranged between the outer layer coil pipe and the outer shell, the outlet header of the outer layer coil pipe is connected with the inlet header of the inner layer coil pipe through a middle header 9, and the middle header is arranged between the outer layer coil pipe and the rear shell of the boiler; boiler working medium is distributed to all outer-layer coil pipes 2 from an outer-layer inlet header 7 through a plurality of inlets from 7-1 to 7-6, enters an outer-layer outlet header 8 after the outer-layer coil pipes absorb smoke heat, enters an inner-layer inlet header 10 through a middle header 9, is redistributed to inner-layer coil pipes 12 to absorb smoke radiation heat and convection heat, and finally, hot water is produced and supplied to users from an inner-layer outlet header 11. The inlet and outlet headers of the inner layer coil pipe and the outer layer coil pipe can be arranged at the same side of the boiler or at different sides. The specific shape of the header can be adjusted according to the process, the flow velocity of the boiler working medium in the inner layer coil pipe is not less than 0.5m/s, the flow velocity of the boiler working medium in the outer layer coil pipe is not less than 0.3m/s, and an exhaust valve is arranged at the top of the header or the outlet pipe.

As shown in fig. 8, the smoke outlet 4 can be located at the upper side of the casing, the front cover plate 17 and the rear cover plate 18 can be free from being coated with refractory materials, an annular guide plate 19-1 is arranged between the outer layer coil 2 and the casing 1 to wrap the outer layer coil and the front and rear cover plates, a long circular hole with the same cross section as that of the long circular combustion head is arranged at the rear end of the annular guide plate, smoke absorbs heat and heats in the process of flushing the front and rear cover plates under the action of the annular guide plate 19-1, the relative humidity of smoke emission is reduced, and white smoke plume is eliminated in part of time.

As shown in figure 9, the smoke outlet 4 can be arranged at the upper side of the shell, an arched guide plate 19-2 is arranged at the position 100 mm-200 mm below the smoke outlet 4, and the arched guide plate is fixed by a tension brace 6. The thickness of the arched flow guide plate is 10 mm-20 mm, and the chord length is slightly larger than the length of the semicircular section of the outer-layer coil pipe. As shown in the figure, the flue gas flowing path can block the flow of the flue gas from directly passing through the smoke outlet, the flue gas heat transfer flow is increased, and the heat transfer effect is greatly improved.

As shown in fig. 10, the water system design may employ an annular header arrangement. Taking the outer-layer annular header as an example, the rear end of the outer-layer coil 2 is sequentially provided with an outer-layer annular inlet header 20 and an outer-layer annular outlet header 21, and the outer-layer annular inlet/outlet headers are provided with corresponding inlet/outlet annular tube bundles according to the number of coil units. For convenient arrangement, the size of the outer annular outlet header is slightly larger than that of the outer annular inlet header. The outer annular inlet header inlet 22 is arranged above the outer annular inlet header, and the outer annular outlet header outlet 23 is arranged below the outer annular outlet header. Boiler working medium enters from an inlet of the outer-layer annular inlet header, is distributed to each annular water inlet pipe bundle under the action of gravity, enters the outer-layer coil pipe 2 to absorb heat, then enters the respective annular water return pipe bundle to return to the outer-layer annular outlet header 21, enters an inlet of the inner-layer annular inlet header through an outlet 23 of the outer-layer annular outlet header, and is subjected to the same water return process in the inner-layer coil pipe. Each pair of annular tube bundles 24 comprises an annular water inlet tube bundle and an annular water return tube bundle, and is responsible for the water inlet and return of each coil unit: working medium enters the coil pipe for heat exchange through the water inlet pipe bundle and flows out of the coil pipe through the water return pipe bundle and returns to the outlet header. The distributed arrangement of the tube bundles reduces the tube diameters of the tube bundles, can effectively reduce the local uneven heat transfer caused by the concentrated arrangement of the header, leads the heat transfer process to tend to be mild, and achieves higher heat transfer coefficient.

In addition, gaps between the front ends and the rear ends of the inner-layer coil pipe and the cover plate and gaps between the inlet and the outlet of the coil pipe need to be filled, so that a smoke corridor is prevented from being formed, and the abrasion of the pipe wall is aggravated.

Claims (10)

1. A rectangular cross section long circular double-coil gas condensation hot water boiler structure is characterized by sequentially comprising a shell (1), an outer-layer coil (2), an inner-layer coil (12) and a long circular cross section burner (15) from outside to inside, a front cover plate (17) arranged at the front ends of the inner-layer coil (12) and the outer-layer coil (2) and a rear cover plate (18) arranged at the rear end of the inner-layer coil (12) and the outer-layer coil (2), an outer-layer inlet header (7) and an outer-layer outlet header (8) arranged at the same side or different sides of the outer-layer coil (2), an inner-layer inlet header (10) and an inner-layer outlet header (11) arranged at the same side or different sides of the inner-layer coil (12), and a middle header (9) arranged between the outer-layer coil (; a condensing pipe (16) is arranged at the bottom of the shell (1); the combustion head (15) with the long circular cross section is arranged in the center of a hearth formed by the inner-layer coil pipe (12), the front cover plate (17) and the rear cover plate (18); the boiler adopts the design of inside and outside double-deck coil pipe, and the internal face of inlayer coil pipe (12) forms confined furnace with front shroud (17) and back shroud (18), absorbs flue gas radiant heat and convection heat, and inlayer coil pipe (12) and outer coil pipe (2) degree of depth cooling condensation flue gas, and the flue gas is successively through double-deck coil pipe heat transfer, flows to exhaust port (4) along casing nearly wall flue gas passageway (5) to through condenser pipe (16) discharge comdenstion water.

2. The long circular double-coil gas condensation hot water boiler structure with the rectangular cross section according to claim 1, characterized in that a front cover plate (17) and a rear cover plate (18) which are internally coated with refractory materials are correspondingly arranged between the front and the rear of the inner-layer coil (12) and the outer-layer coil (2) and the shell (1), the front cover plate (17) is used for fixing a burner, the front cover plate (17) and the rear cover plate (18) form a closed space to enhance the air tightness of the coil heat exchange, and high-temperature flue gas generated by the burner is forced to continuously flow through the side gaps of the double coils; and a fire observation hole, an ignition needle and a fire detection needle preformed hole are arranged on the front cover plate (17) and are used for observing and adjusting the combustion state and feeding back in time.

3. The structure of the rectangular cross section oblong double-coil gas condensation hot water boiler according to claim 1, characterized in that the inner coil (12) and the outer coil (2) are both oblong coils, and according to the capacity and the actual situation of the hot water boiler, the straight section of the inner coil (12) is 300 mm-1800 mm, and the semi-circle section of the inner coil (12) is 130 mm-780 mm; the length of the straight section of the outer-layer coil pipe (2) is 1-1.2 times of that of the straight section of the inner-layer coil pipe, and the length of the semicircular section of the outer-layer coil pipe (2) is 1.2-1.8 times of that of the semicircular section of the inner-layer coil pipe; the height of the cross section of the long circular coil pipe is 15-30 mm, and the effective width is 30-120 mm; the inner layer coil pipe (12) and the outer layer coil pipe (2) are stacked together from front to back, and the gap between the coil pipes can be positioned by comb teeth, positioning gaskets (14) or bulge protrusions.

4. The long circular double-coil gas condensation hot water boiler structure with the rectangular cross section according to claim 1, wherein the long circular cross section combustion head (15) is arranged in the center of a hearth, the long circular coil is matched to ensure that smoke is uniformly distributed along the circumference, 50-1000 mm is reserved between the outer surface of the long circular cross section combustion head (15) and the inner surface of the inner coil (12) to prevent flame from directly washing the inner surface of the long circular inner coil (12) to cause incomplete combustion and carbon deposition, the inlet end of the long circular cross section combustion head (15) is provided with a refractory material section to ensure that a flame surface of the long circular cross section combustion head (15) is positioned in the center of the hearth, and the length of the long circular cross section combustion head (15) accounts for 20-100% of the length of the hearth; the length of the straight section of the cross section of the combustion head (15) with the oblong cross section is 70-420 mm, and the length of the semi-circle section of the cross section of the combustion head (15) with the oblong cross section is 30-180 mm.

5. The long circular double-coil gas condensation hot water boiler structure with the rectangular cross section according to claim 1, wherein 1-50 coil units are arranged on the inner-layer coil (12) and the outer-layer coil (2) according to the difference of the capacity of the hot water boiler, the number of coils of each coil unit is 1-50, the gap between the inner-layer coils is 0.5-2.0 mm, and the gap between the outer-layer coils is 0.4-2.0 mm; the inner-layer coil pipe (12) and the outer-layer coil pipe (2) are welded with two ends of the coil pipe by adopting 90-degree elbows to form a water inlet and a water outlet which are positioned on the same plane.

6. The long circular double-coil gas condensation hot water boiler structure with the rectangular cross section according to claim 1, characterized in that the inner coil (12) and the outer coil (2) are provided with inlet and outlet headers, the inner inlet header (10) and the inner outlet header (11) of the inner coil (12) are arranged between the inner coil (12) and the outer coil (2), the outer inlet header (7) and the outer outlet header (8) of the outer coil (2) are arranged between the outer coil (2) and the outer shell (1), the outer outlet header (8) of the outer coil (2) is connected with the inner inlet header (10) of the inner coil (12) through a middle header (9), and the middle header (9) is arranged between the outer coil (2) and the rear shell of the boiler; boiler working media are distributed to all outer-layer coil pipes (2) through an outer-layer inlet header (7), enter an outer-layer outlet header (8) after the outer-layer coil pipes (2) absorb smoke heat, are guided into an inner-layer inlet header (10) through a middle header (9), are redistributed into an inner-layer coil pipe (12) to absorb smoke radiation heat and convection heat, and finally, produced hot water is supplied to users from an inner-layer outlet header (11); wherein, the flow velocity of the boiler working medium in the inner layer coil pipe (12) is not less than 0.5m/s, the flow velocity of the boiler working medium in the outer layer coil pipe (2) is not less than 0.3m/s, and an exhaust valve is arranged on the top of the outer layer outlet header (8) or the outlet pipe.

7. A rectangular cross-section oblong double-coil gas condensation hot water boiler structure according to claim 1, characterized in that the inner coil (12) and the outer coil (2) are each provided with 4 to 24 tie rods (6) for supporting the coils and fastening the coils, the tie rods (6) being fixed to the outer support of the boiler.

8. The long circular double-coil gas condensation hot water boiler structure with the rectangular cross section according to claim 7, wherein the shell is made of plastic or butyl rubber, a condensing pipe (16) is arranged at the bottom of the shell, the smoke outlet (4) is arranged at the tail of the boiler or at the upper side of the shell of the boiler, and smoke subjected to heat exchange through the outer-layer coil (2) flows to the smoke outlet (4) along the channel (5) near the wall surface of the shell.

9. The long round double-coil gas condensation hot water boiler structure with the rectangular cross section according to claim 8, characterized in that an annular guide plate (19-1) is arranged between the outer coil (2) and the shell (1) to wrap the outer coil (2), the front cover plate (17) and the rear cover plate (18), and the rear end of the annular guide plate (19-1) is provided with a long round hole with the same cross section as that of the long round cross section burner (15); under the action of the annular guide plate (19-1), the smoke absorbs heat and heats up in the process of flushing the front cover plate and the rear cover plate, the relative humidity of the discharged smoke is reduced, and white smoke plume is eliminated in part of time; when the smoke outlet (4) is arranged on the upper side of the shell, an arched guide plate (19-2) is arranged at a position 100-200 mm below the smoke outlet, the arched guide plate (19-2) is fixed by a stay rod (6), and the chord length of the arched guide plate (19-2) is slightly larger than the semi-circle segment length of the outer-layer coil pipe (2).

10. The long round double-coil gas condensation hot-water boiler structure with the rectangular cross section according to claim 1, characterized in that an outer annular inlet header (20) and an outer annular outlet header (21) are sequentially arranged at the rear end of the outer coil (2), the outer annular inlet header (20) and the outer annular outlet header (21) are provided with corresponding inlet and outlet annular tube bundles (24) according to the number of coil units of the outer coil (2), each pair of annular tube bundles (24) comprises an annular inlet pipe bundle and an annular return pipe bundle and is responsible for inlet and return water of each coil unit; for convenient arrangement, the size of the outer annular outlet header (21) is larger than that of the outer annular inlet header (20), an inlet (22) of the outer annular inlet header is arranged above the outer annular inlet header (20), and an outlet (23) of the outer annular outlet header is arranged below the outer annular outlet header (21); boiler working media enter from an outer-layer annular inlet header inlet (22), are distributed to each annular water inlet pipe bundle under the action of gravity, enter the outer-layer coil pipe (2) to absorb heat, then enter respective annular water return pipe bundles, return to the outer-layer annular outlet header (21), enter the inner-layer annular inlet header inlet through an outer-layer annular outlet header outlet (23), and perform the same water return process on the inner-layer coil pipe (12); the working medium enters the coil pipe for heat exchange through the annular water inlet pipe bundle and flows out of the coil pipe through the annular water return pipe bundle to return to the outlet header.

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