CN217422597U

CN217422597U - Air inlet silencer and gas water heating system

Info

Publication number: CN217422597U
Application number: CN202123366395.1U
Authority: CN
Inventors: 卢宇聪; 张锦梁; 余浩伦; 龚文添
Original assignee: Guangdong Vanward New Electric Co Ltd
Current assignee: Guangdong Vanward New Electric Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-09-13
Anticipated expiration: 2031-12-28

Abstract

The utility model relates to a silencing device and gas hot water system admit air. The utility model discloses a silencing device admits air includes casing and air inlet cylinder, the holding chamber has in the casing, the holding intracavity is located to the air inlet cylinder, inlet channel has in the air inlet cylinder, the one end of air inlet cylinder is equipped with the air inlet with the inlet channel intercommunication, the other end of air inlet cylinder is the shutoff state, the other end of air inlet cylinder is equipped with the baffle, inlet channel is separated into with the holding chamber to air inlet cylinder and baffle, air inlet chamber and inflation chamber, the lateral wall of air inlet cylinder is equipped with the multiunit along air inlet punch combination of air inlet cylinder circumference interval arrangement, inlet channel passes through air inlet punch combination and air inlet chamber intercommunication, the baffle is equipped with the diffusion punch combination, the air inlet chamber is through diffusion punch combination and inflation chamber intercommunication. The air flow flows into the air inlet channel from the air inlet, then flows to the air inlet cavity through the air inlet hole group, then the air flow in the air inlet cavity reaches the expansion cavity through the diffusion hole group, the air flow expands and is stabilized in the expansion cavity, and finally the air flow smoothly and stably flows out of the silencing air inlet device.

Description

Air inlet silencer and gas water heating system

Technical Field

The utility model relates to gas hot water system technical field especially relates to an admit air silencing device and gas hot water system.

Background

Generally, a certain amount of operating noise is generated during the operation of gas water heaters, and other gas water heaters, and the noise mainly comes from combustion noise, water flow noise, intake and exhaust airflow noise, fan operating noise, and the like. When the heat load demand is bigger, the load power of each part of the gas water heating equipment is increased, the operation noise is changed and increased, and especially when the long-term gas water heating equipment is in the heavy load demand, the noise generated by the long-term operation of the machine inevitably affects the home comfortable environment of a user, thereby causing noise trouble to the user and affecting the user experience.

Along with the development maturity of technique, combustion apparatus and indirect heating equipment are all improving constantly and are optimizing, and burning noise and heat exchange pipeline rivers noise can be controlled at better low noise level, but on some do not have the gas hot water system of the special design amortization structure that admits air, the induction port noise is still more obvious when the fan moves in the noise of admitting air of air, and user experience is still relatively poor.

SUMMERY OF THE UTILITY MODEL

One of the technical problems solved by the present invention is to provide an air intake silencer for at least solving the problem of poor noise reduction effect of the existing combustion equipment.

The second technical problem solved by the present invention is to provide a gas water heating system for at least solving the problem of poor noise reduction effect of the existing combustion equipment.

The first technical problem is solved by the following technical scheme:

an air inlet silencing device is applied to a gas hot water system and comprises:

the device comprises a shell, a first fixing piece and a second fixing piece, wherein an accommodating cavity is formed in the shell;

the air inlet cylinder is arranged in the accommodating cavity, an air inlet channel is arranged in the air inlet cylinder, an air inlet communicated with the air inlet channel is arranged at one end of the air inlet cylinder, the other end of the air inlet cylinder is in a blocking state, a partition plate is arranged at the other end of the air inlet cylinder, and the accommodating cavity is divided into the air inlet channel, an air inlet cavity and an expansion cavity by the air inlet cylinder and the partition plate;

the side wall of the air inlet cylinder is provided with a plurality of groups of air inlet holes which are arranged along the circumferential direction of the air inlet cylinder at intervals, the air inlet channel is communicated with the air inlet cavity through the air inlet hole groups, the partition plate is provided with diffusion hole groups, and the air inlet cavity is communicated with the expansion cavity through the diffusion hole groups.

Compared with the background art, the heat exchange mechanism has the advantages that:

this technical scheme's silencing device that admits air is when the operation, and the air current flows into to inlet channel from the air inlet, then flows into the chamber of admitting air through the inlet port group, realizes the first diversion to the air current that admits air, makes the air current preliminary slow down, then the air current in the chamber of admitting air passes through the diffusion hole group and reachs the inflation chamber, and the air current is at inflation chamber steady voltage, makes its velocity of flow further slow down, finally makes the air current gently stably flow out silencing air inlet unit, has played the effect of amortization noise reduction from this.

In one embodiment, the inlet set includes a first plurality of circular apertures spaced axially along the inlet barrel.

In one embodiment, the inlet set comprises at least one second circular hole and at least one elongated hole arranged at intervals along the axial direction of the inlet barrel.

In one embodiment, a flow guide inlet nozzle is arranged at one end of the inlet cylinder, the inlet is communicated with the inside of the flow guide inlet nozzle and the inlet channel, and the inner diameter of the flow guide inlet nozzle is gradually reduced along the inlet direction.

In one embodiment, the diffusion hole set includes a plurality of diffusion holes arranged circumferentially about the axis of the intake barrel.

In one embodiment, soundproof cotton is arranged in the air inlet cavity.

In one of them embodiment, the casing includes first half shell and second half shell, the peripheral outside of first half shell with one of the peripheral outside of second half shell is equipped with the buckle groove of interval setting, the peripheral outside of first half shell with another one of the peripheral outside of second half shell is equipped with the buckle of interval setting, the buckle with the cooperation of buckle groove is connected.

In one embodiment, one end of the shell is provided with an avoiding opening for the air inlet cylinder to penetrate through, the side wall of the air inlet cylinder is provided with an annular positioning groove, and the avoiding opening is in clamping fit with the positioning groove.

In one embodiment, an air outlet shell is further arranged on one side of the shell, the air outlet shell is provided with an air outlet cavity, one end of the air outlet shell is provided with an air outlet communicated with the air outlet cavity, the other end of the air outlet shell is connected with the shell, and the air outlet cavity is communicated with the expansion cavity.

The second technical problem is solved by the following technical scheme:

a gas fired water heating system comprising:

the air inlet silencing device is the air inlet silencing device;

the inlet end of the air-fuel premixer is connected with the air inlet silencer;

the inlet end of the variable frequency blower is connected with the outlet end of the air-fuel premixer;

the inlet end of the full-premix combustion structure is connected with the outlet end of the variable-frequency blower;

and the condensing heat exchanger is connected with the outlet end of the full-premixing combustion structure.

Compared with the background art, the gas hot water system has the beneficial effects that:

through using the gas hot water system among this technical scheme, wherein silencing device admits air when the operation, the air current flows into to inlet channel from the air inlet, then the chamber of admitting air through the flow direction of admitting air punch combination, the first diversion to the air current of admitting air is realized, make the air current preliminary slow down, then the air current in the chamber of admitting air passes through the diffusion punch combination and reaches the expansion chamber, the air current is at the expansion chamber steady voltage, make its velocity of flow further slow down, finally make the air current smoothly stably flow out silencing air inlet unit, the effect of making an uproar falls has been played from this.

Drawings

FIG. 1 is a partial sectional view of the overall structure of the intake silencer of the present invention;

FIG. 2 is an exploded view of the intake silencer assembly of FIG. 1;

fig. 3 is a sectional view showing the entire structure of the intake silencer in fig. 1;

FIG. 4 is a sectional view showing the overall construction of a second embodiment of the intake silencer assembly of FIG. 1;

FIG. 5 is a sectional view showing the entire structure of a third embodiment of the intake silencer assembly of FIG. 1;

fig. 6 is a schematic view of the overall structure of the medium gas hot water system of the present invention.

Description of the reference symbols:

100. an intake silencer; 10. a housing; 11. a first half shell; 111. buckling; 12. a second half shell; 121. a fastening groove; 13. an intake passage; 14. an air inlet cavity; 141. sound insulation cotton; 15. an expansion chamber; 20. an air inlet cylinder; 21. a partition plate; 211. a diffusion hole; 22. a first circular hole; 23. a second circular hole; 24. a strip-shaped hole; 25. positioning a groove; 30. a flow guiding air inlet nozzle; 40. an air outlet shell; 41. an air outlet cavity; 42. mounting lugs; 43. a pressure taking port;

200. an air-fuel premixer;

300. a variable frequency blower;

400. a fully premixed combustion structure;

500. a condensing heat exchanger.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second", third ", fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to imply that the number of indicated technical features is essential. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Fig. 1 is a partial sectional view of the overall structure of the middle intake silencer of the present invention. Fig. 2 is an exploded view of the intake silencer assembly of fig. 1. Fig. 3 is a sectional view showing the entire structure of the intake silencer in fig. 1. As shown in fig. 1, 2 and 3 (arrow is airflow direction in the figure), the utility model provides an air inlet silencing device includes casing 10 and air inlet cylinder 20, the holding chamber has in the casing 10, air inlet cylinder 20 locates the holding intracavity, inlet channel 13 has in the air inlet cylinder 20, the one end of air inlet cylinder 20 is equipped with the air inlet with inlet channel 13 intercommunication, air inlet cylinder 20's the other end is the shutoff state, air inlet cylinder 20's the other end is equipped with baffle 21, air inlet cylinder 20 and baffle 21 separate into inlet channel 13 with the holding chamber, inlet chamber 14 and inflation chamber 15, air inlet cylinder 20's lateral wall is equipped with the multiunit along air inlet cylinder 20 circumference interval arrangement's inlet hole group, inlet channel 13 is through inlet hole group and inlet chamber 14 intercommunication, baffle 21 is equipped with diffusion hole 211 group, inlet chamber 14 communicates with inflation chamber 15 through diffusion hole 211 group and inflation chamber 15 through diffusion hole 211 group

When the intake silencer 100 of the technical scheme operates, airflow flows into the intake passage 13 from the intake port, then flows to the intake cavity 14 through the intake hole group, the first diversion of the intake airflow is realized, the airflow is primarily decelerated, then the airflow in the intake cavity 14 reaches the expansion cavity 15 through the diffusion hole 211 group, the airflow is expanded and stabilized in the expansion cavity 15, the flow speed of the airflow is further decelerated, and finally the airflow smoothly and stably flows out of the intake silencer, so that the effects of silencing and reducing noise are achieved.

In one embodiment, as shown in FIG. 3, the inlet set includes a first plurality of circular apertures 22 spaced axially along the inlet barrel 20. In this embodiment, the inlet port group includes a plurality of first circular ports 22, and sets up along the axial interval of air inlet cylinder 20, can make inlet channel 13 and air inlet chamber 14 can carry out the even circulation of air of very large area, carries out the problem that the in-process that the amortization was carried out to the air at inlet silencer 100 and can not produce the air jam, has promoted the reliability.

In one embodiment, as shown in fig. 5, the inlet set includes at least one second circular hole 23 and at least one elongated hole 24 spaced axially along the inlet barrel 20. In this embodiment, adopt the combination form of a rectangular hole 24 and two second circular ports 23, and two second circular ports 23 locate the both sides of rectangular hole 24 respectively, can make air inlet channel 13 and air intake chamber 14 can carry out the even circulation of air of very large tracts of land equally, carry out the problem that the in-process that silences can not produce the air jam at air inlet silencing device 100 to the air, promoted the reliability.

Specifically, in other embodiments of the present invention, the inlet hole group can also be a combined structure of other numbers or shapes, the present invention does not provide a one-to-one example, any structure of the inlet hole group that can make the air flow turn to the next space and perform uniform rectification and diffusion all belongs to the protection scope of the present invention.

In one embodiment, as shown in fig. 3, a flow guide inlet nozzle 30 is provided at one end of the inlet cylinder 20, the inlet communicates with the inside of the flow guide inlet nozzle 30 and the inlet passage 13, and the inner diameter of the flow guide inlet nozzle 30 is gradually reduced along the inlet direction. Can make the gas in the collection casing 10 outside of water conservancy diversion suction nozzle 30 very big degree like this for inside gas enters into casing 10, simultaneously because the internal diameter of water conservancy diversion suction nozzle 30 changes, can make the air that enters into in the inlet channel 13 have certain velocity of flow pressure, make it pass through inlet channel 13 fast, carry out the replenishment of air for subsequent structure, promote the reliability.

In one embodiment, as shown in fig. 2, the diffusion hole 211 set includes a plurality of diffusion holes 211 arranged circumferentially about the axis of the intake cylinder 20. In this embodiment, diffusion hole 211 is equipped with four, and four diffusion holes 211 are just evenly set up along baffle 21's circumference interval, and diffusion hole 211's in this embodiment hole area is great, can circulate to inflation chamber 15 through diffusion hole 211 after the air that is located air inlet chamber 14 strikes the casing 10 inner wall, because diffusion hole 211's a great number and hole area are great, can make the air flow to inflation chamber 15 by air inlet chamber 14 fast, promote the flow efficiency of air.

In one embodiment, as shown in fig. 4, sound insulation 141 is provided in the intake chamber 14. In this embodiment, under the condition that the intake resistance is not affected, the soundproof cotton 141 (or the sound absorption material with smaller airflow resistance) can be embedded in the inner surface of the casing 10 or in the intake cavity 14 (or be selected), so that the airflow noise can be further absorbed, the propagation of the noise can be blocked, and a better noise reduction effect can be achieved.

In one embodiment, as shown in fig. 2, the housing 10 includes a first half shell 11 and a second half shell 12, one of the outer side of the periphery of the first half shell 11 and the outer side of the periphery of the second half shell 12 is provided with fastening grooves 121 arranged at intervals, the other of the outer side of the periphery of the first half shell 11 and the outer side of the periphery of the second half shell 12 is provided with fastening buckles 111 arranged at intervals, and the fastening buckles 111 and the fastening grooves 121 are in fit connection. In this embodiment, the housing 10 is of a split structure, which facilitates assembly and disassembly of the housing 10 and the intake barrel 20 of the intake silencer 100, and improves convenience. Meanwhile, the first half shell 11 and the second half shell 12 are connected in a snap 111 matching mode, and the connecting structure is simple in structure, stable in connection and has certain stability.

In one embodiment, as shown in fig. 3, an end of the casing 10 is provided with an avoidance opening through which the intake barrel 20 passes, and a side wall of the intake barrel 20 is provided with an annular positioning groove 25, and the avoidance opening is in snap fit with the positioning groove 25. The avoiding opening and the positioning groove 25 can stably connect the shell 10 and the air inlet cylinder 20, and the stability of the whole air inlet silencer 100 is improved.

In one embodiment, as shown in fig. 1 and 3, an air outlet shell 40 is further provided on one side of the housing 10, the air outlet shell 40 has an air outlet cavity 41, one end of the air outlet shell 40 is provided with an air outlet communicated with the air outlet cavity 41, the other end of the air outlet shell 40 is connected with the housing 10, and the air outlet cavity 41 is communicated with the expansion cavity 15. In the present embodiment, air can flow in the intake silencer 100 from the intake port of the casing 10, the intake passage 13, the intake chamber 14, the expansion chamber 15, the exhaust chamber 41, and the exhaust port. The air outlet is used for being connected with the air-fuel premixer 200, wherein the air outlet shell 40 is provided with a pressure taking port 43 for taking pressure in real time so as to detect the air flow pressure and converting the pressure to be used as a feedback signal for controlling and adjusting the rotating speed of the fan, so that the wind speed of the fan is always matched with the combustion power load.

Specifically, as shown in FIG. 1, the top end of the outlet housing 40 is further provided with a mounting ear 42 for connection with the air-fuel premixer 200.

Further, the utility model discloses well air inlet noise reduction device 100's operation process does: the air flow which is rapidly disturbed due to the suction force of the fan firstly and quickly enters the air inlet channel 13 from the air inlet of the shell 10 and is uniformly diffused to the air inlet cavity 14 for the first time through the air inlet hole group, and the noise of the air flow can be weakened for the first time due to the fact that the air flow is folded. Then the airflow uniformly enters the expansion cavity 15 through the diffusion holes 211, the airflow sound can be further weakened due to the fact that the airflow is bent for the second time in the process, then the air flowing into the expansion cavity 15 passes through the air outlet cavity 41 and is uniformly sucked by the suction force of the fan, the airflow in the process is subjected to expansion in the expansion cavity 15, the pressure stabilizing effect is achieved, and the airflow sound can be further reduced.

Specifically, when the impeller noise generated by the operation of the fan is transmitted to the air intake silencer 100 through the air intake port of the fan, the transmitted noise is maximally attenuated by being folded and transmitted downwards in the transmission path communicated with the air intake silencer 100 due to the fact that the noise path is opposite to the air intake path, so that the wind speed noise transmitted through the air intake port of the fan is reduced, and the reliability is improved.

The utility model provides a silencing device 100 that admits air is small and exquisite compact, and the air current that admits air is stable even, effectively weakens the noise and propagates, is applied to gas hot water system, can effectively reduce the air current noise that admits air, the fan operation noise of passing outward, improves the silence effect of machine greatly, provides the good silence of user and experiences.

The utility model also provides a gas hot water system, as shown in figure 6, include:

an intake silencer 100, the intake silencer 100 being the intake silencer 100;

the inlet end of the air-fuel premixer 200 is connected with the air inlet silencer 100;

the inlet end of the variable frequency blower 300 is connected with the outlet end of the air-fuel premixer 200;

the inlet end of the full-premix combustion structure 400 is connected with the outlet end of the variable-frequency blower 300;

and a condensing heat exchanger 500, wherein the condensing heat exchanger 500 is connected with the outlet end of the fully premixed combustion structure 400.

The utility model discloses a gas hot-water heating system compares with the background art, and the beneficial effect who has is:

through using the gas hot water system among this technical scheme, wherein inlet air silencing device 100 when the operation, the air current flows into to inlet channel 13 from the air inlet, then flow to air intake chamber 14 through the inlet port group, realize the first diversion to the air current of admitting air, make the air current preliminary slow down, then the air current in air cavity 14 reaches expansion chamber 15 through diffusion hole 211 group, the air current is at expansion chamber 15 expansion steady voltage, make its velocity of flow further slow down, finally make the air current gently stably flow out silencing air inlet unit, thereby played the effect of amortization noise reduction.

Further, in the present embodiment, the gas hot water system includes an air-fuel premixer 200, a variable frequency blower 300, and a fully premixed combustion structure 400. The air-fuel premixer 200 is installed at the air inlet side of the variable frequency blower 300, and mixes the fuel gas and air delivered from the air delivery pipe in proportion. The variable frequency blower 300 is hermetically connected with the fan mounting port of the fully premixed combustion structure 400 through a fan sealing gasket, so that premixed gas is prevented from leaking.

Further, the fully premixed combustion structure 400 performs uniform flow guiding distribution on the incoming mixed gas in the upper cover body gas inlet cavity, so that the mixed gas is uniformly distributed, and the gas is uniformly and stably combusted on the surface of the combustor. The combustion structure has the characteristics of uniform gas outlet, stable combustion and high efficiency, and keeps relatively low combustion noise.

Further, the heat exchanger realizes heat exchange between high-temperature flue gas and low-temperature cold water, and heats the cold water for utilization. The gas water heater can provide heating water for building and living bath water. The working process comprises the following steps: the system heating backwater enters the heat exchange tube core of the condensing heat exchanger through the backwater water inlet, the heat exchange tube core and the flue gas undergo partition type reverse turbulence heat exchange, the heat exchange tube core ascends to the top high-temperature heat exchange area after condensation heat exchange to complete heat exchange, and then the heat exchange tube flows out through the water outlet ring pipe of the high-temperature area, so that the heat exchange process of the whole heat exchanger is repeatedly and continuously completed in a circulating mode, and heating hot water and domestic bathroom hot water are supplied to the outside.

In the detailed description of the embodiments, various technical features may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The detailed description of the above embodiments only expresses several embodiments of the present invention, and the description thereof is more specific and detailed, but should not be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. The utility model provides an air inlet silencing device, is applied to gas hot water system, its characterized in that includes:

the shell (10), the shell (10) has a containing cavity therein;

the air inlet cylinder (20) is arranged in the accommodating cavity, an air inlet channel (13) is arranged in the air inlet cylinder (20), an air inlet communicated with the air inlet channel (13) is formed in one end of the air inlet cylinder (20), the other end of the air inlet cylinder (20) is in a blocking state, a partition plate (21) is arranged at the other end of the air inlet cylinder (20), and the accommodating cavity is divided into the air inlet channel (13), an air inlet cavity (14) and an expansion cavity (15) by the air inlet cylinder (20) and the partition plate (21);

the side wall of the air inlet cylinder (20) is provided with a plurality of groups of air inlet hole groups which are arranged along the circumferential direction of the air inlet cylinder (20) at intervals, the air inlet channel (13) is communicated with the air inlet cavity (14) through the air inlet hole groups, the partition plate (21) is provided with a diffusion hole (211) group, and the air inlet cavity (14) is communicated with the expansion cavity (15) through the diffusion hole (211) group.

2. The intake silencer assembly of claim 1, wherein the set of intake holes includes a first plurality of circular apertures (22) spaced axially along the intake barrel (20).

3. An inlet silencer according to claim 1, characterized in that the inlet group comprises at least one second circular hole and at least one elongated hole (23) arranged axially spaced along the inlet barrel (20).

4. The intake silencer according to claim 1, wherein a flow guide intake nozzle (30) is provided at one end of the intake cylinder (20), the intake port communicates with the inside of the flow guide intake nozzle (30) and the intake passage (13), and the inner diameter of the flow guide intake nozzle (30) is gradually reduced along the intake direction.

5. The intake silencer assembly of claim 1, wherein the set of diffusion holes (211) includes a plurality of diffusion holes (211) arranged circumferentially about an axis of the intake barrel (20).

6. An air intake silencer assembly according to claim 1, wherein sound-insulating wool (141) is provided in the air intake chamber (14).

7. The intake silencer assembly of claim 1, wherein the housing (10) includes a first half shell (11) and a second half shell (12), one of the outer side of the periphery of the first half shell (11) and the outer side of the periphery of the second half shell (12) is provided with spaced-apart snap (111) grooves, the other of the outer side of the periphery of the first half shell (11) and the outer side of the periphery of the second half shell (12) is provided with spaced-apart snap (111), and the snap (111) grooves are cooperatively connected.

8. The intake silencer of claim 1 or 7, wherein an avoiding opening is formed in one end of the casing (10) for the intake barrel (20) to penetrate through, an annular positioning groove (24) is formed in the side wall of the intake barrel (20), and the avoiding opening is in clamping fit with the positioning groove (24).

9. The intake silencer of claim 1, wherein an outlet housing (40) is further disposed on one side of the housing (10), the outlet housing (40) has an outlet cavity (41), an outlet port communicating with the outlet cavity (41) is disposed at one end of the outlet housing (40), the other end of the outlet housing (40) is connected to the housing (10), and the outlet cavity (41) communicates with the expansion cavity (15).

10. A gas fired water heating system, comprising:

an intake silencer assembly (100), said intake silencer assembly (100) being the intake silencer assembly (100) of any of claims 1-9;

the inlet end of the air-fuel premixer (200) is connected with the air inlet silencing device (100);

the inlet end of the variable frequency blower (300) is connected with the outlet end of the air-fuel premixer (200);

the inlet end of the full-premix combustion structure (400) is connected with the outlet end of the variable-frequency blower (300);

a condensing heat exchanger (500), the condensing heat exchanger (500) being connected with an outlet end of the fully premixed combustion structure (400).