CN216769768U

CN216769768U - Low-nitrogen water heater based on flue gas self-circulation

Info

Publication number: CN216769768U
Application number: CN202123336750.0U
Authority: CN
Inventors: 艾穗江; 黄城洪; 邓海燕
Original assignee: Guangdong Macro Gas Appliance Co Ltd
Current assignee: Guangdong Macro Gas Appliance Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-06-17
Anticipated expiration: 2031-12-28

Abstract

The utility model discloses a low-nitrogen water heater based on flue gas self-circulation, which comprises: the combustor, the heat exchanger and the smoke exhaust device are arranged in the shell, and a smoke exhaust pipe and an air inlet pipe are connected with the smoke exhaust device; the water heater is characterized in that the air inlet pipe and the smoke exhaust pipe are coaxially arranged on the upper portion of the shell, an air inlet is formed in the air inlet pipe, a first smoke outlet used for discharging smoke out of the shell and a second smoke outlet corresponding to an air inlet channel of the air inlet pipe are formed in the smoke exhaust pipe, and the second smoke outlet enables smoke discharged through the second smoke outlet to return to the water heater through the air inlet pipe. The smoke exhaust outlet is communicated with the air inlet, and the negative pressure generated by the fan is utilized to drive smoke to achieve a self-circulation effect, so that combustion air entering the combustor is changed into a stable smoke and air mixture, the effects of diluting oxygen and preheating fuel are achieved, the combustion peak temperature can be effectively reduced, and the emission of NOx is reduced.

Description

Low-nitrogen water heater based on flue gas self-circulation

Technical Field

The utility model relates to the technical field of gas water heating equipment, in particular to a low-nitrogen water heater based on flue gas self-circulation.

Background

With the development of economy, the emission hazard of NOx is more and more obvious, and the reduction of NOx is more and more important, and the research is continuous as large as an industrial boiler and as small as a gas water heater. The low-nitrogen technology of the existing gas water heater generally adopts the technologies of dense-dilute combustion or water-cooled burners and the like, and the structures of the dense-dilute burners and the water-cooled low-nitrogen technology are complex and large, so that the cost of the water heater is greatly increased, the universality of parts is low, and the production process is difficult.

An existing flue gas circulation water heater, such as a gas water heater with a flue gas circulation system, disclosed in chinese patent application with publication number CN106871445A, includes: the combustion chamber, the forced-blowing direct-current fan, the primary heat exchanger and the secondary heat exchanger which are communicated with the combustion chamber, and the main controller which is connected with the forced-blowing direct-current fan; cold water flowing out of a water inlet pipe of the gas water heater firstly enters a secondary heat exchanger for heat exchange, and water flowing out of the secondary heat exchanger enters a primary heat exchanger for heating; the device is characterized in that a smoke circulating channel for communicating the secondary heat exchanger with the combustion chamber is arranged outside the combustion chamber, an electric control air valve for controlling the opening degree of the channel is arranged on the smoke circulating channel, and the electric control air valve is connected with a main controller. The smoke circulating system needs to adopt additional parts, so that the cost is high and the processing technology is difficult.

Disclosure of Invention

Aiming at the problems in the prior art, the utility model aims to provide a low-nitrogen water heater based on flue gas self-circulation, which can effectively reduce the combustion peak temperature and reduce the NOx emission.

In order to achieve the purpose, the utility model adopts the following technical scheme.

A low-nitrogen water heater based on flue gas self-circulation comprises: the device comprises a shell, a combustor, a heat exchanger and a smoke exhaust device which are arranged in the shell, a smoke exhaust pipe connected with the smoke exhaust device, and an air inlet pipe for supplementing air to the combustor; the smoke exhaust device comprises a shell, an air inlet pipe, a smoke exhaust pipe, a first smoke outlet and a second smoke outlet, wherein the air inlet pipe and the smoke exhaust pipe are coaxially arranged on the shell, the air inlet pipe is provided with an air inlet, the smoke exhaust pipe is provided with a first smoke outlet and a second smoke outlet, the first smoke outlet and the second smoke outlet are used for discharging smoke out of the shell, the second smoke outlet corresponds to an air inlet channel of the air inlet pipe, and the smoke exhausted through the second smoke outlet flows back into the combustor through the air inlet pipe.

More preferably, the air inlet pipe is sleeved on the periphery of the smoke exhaust pipe, and the smoke exhaust pipe and the air inlet pipe are arranged at intervals; an air inlet channel is formed between the smoke exhaust pipe and the air inlet pipe.

More preferably, the tail end of the smoke exhaust pipe protrudes out of the tail end of the air inlet pipe; the second smoke outlet is positioned on the side wall of the overlapped section of the smoke exhaust pipe and the air inlet pipe, and the first smoke outlet is positioned on the side wall of the smoke exhaust pipe protruding out of the air inlet pipe section.

More preferably, the intake port is located on a side wall of the intake pipe.

More preferably, the housing is a closed structure, and the housing is connected with the air inlet pipe in a sealing manner.

More preferably, the smoke evacuation device includes: and the volute of the fan is connected with the smoke exhaust pipe.

More preferably, the fan is a direct current variable speed fan, and the direct current variable speed fan is connected with a control device of the water heater.

More preferably, the second smoke outlet is provided with an electric control air valve for controlling the opening degree of the second smoke outlet, and the electric control air valve is connected with a control device of the water heater.

More preferably, the second smoke outlet is provided with a gas flow sensor for detecting the smoke flow of the second smoke outlet, and the gas flow sensor is connected with a control device of the water heater.

The utility model has the beneficial effects that: (1) the smoke exhaust outlet is communicated with the air inlet, and the negative pressure generated by the fan is utilized to drive smoke to achieve a self-circulation effect, so that combustion air entering the combustor is changed into a stable smoke and air mixture, the effects of diluting oxygen and preheating fuel are achieved, the combustion peak temperature can be effectively reduced, and the emission of NOx is reduced. (2) The structure is simple, the water heater can keep the same as a common water heater, and the internal structure of the water heater is not required to be modified; the self-circulation gas volume of the flue gas can be adjusted in a self-adaptive manner; the flue gas concentration and the temperature are uniformly mixed, and the combustion is stable. (3) Can be used in combination with the low-nitrogen burner synchronously to further reduce NOx.

Drawings

Fig. 1 is a cross-sectional view of a low-nitrogen water heater based on flue gas self-circulation provided by the utility model.

Reference numerals indicate the same.

1: housing, 2: burner, 3, heat exchanger, 4: a fan, 5: a smoke exhaust pipe, 6: an air inlet pipe.

21: gas nozzle, 51: first smoke outlet, 52: second outlet, 61: an air inlet.

Detailed Description

In the description of the present invention, it should be noted that, for the terms of orientation, such as "central", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., it indicates that the orientation and positional relationship shown in the drawings are based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated without limiting the specific scope of protection of the present invention.

Furthermore, if the terms "first" and "second" are used for descriptive purposes only, they are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. Thus, a definition of "a first" or "a second" feature may explicitly or implicitly include one or more of the feature, and in the description of the utility model, "at least" means one or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "assembled", "connected", and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; or may be a mechanical connection; the two elements can be directly connected or connected through an intermediate medium, and the two elements can be communicated with each other. The specific meanings of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.

In the present application, unless otherwise specified or limited, "above" or "below" a first feature may include the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other through another feature therebetween. Also, the first feature being "above," "below," and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply an elevation which indicates a level of the first feature being higher than an elevation of the second feature. The first feature being "above", "below" and "beneath" the second feature includes the first feature being directly below or obliquely below the second feature, or merely means that the first feature is at a lower level than the second feature.

The following describes the embodiments of the present invention with reference to the drawings of the specification, so that the technical solutions and the advantages thereof are more clear and clear. The embodiments described below are exemplary and are intended to be illustrative of the utility model, but are not to be construed as limiting the utility model.

As shown in fig. 1, a low-nitrogen water heater based on flue gas self-circulation comprises: the water heater comprises a shell 1, a combustor 2, a heat exchanger 3 and a smoke exhaust device which are arranged in the shell 1, a smoke exhaust pipe 5 connected with the smoke exhaust device, and an air inlet pipe 6 for supplying air to the combustor, wherein the air inlet pipe 6 and the smoke exhaust pipe 5 are coaxially arranged on the upper part of the shell 1, and the water heater is characterized in that an air inlet 61 is arranged on the air inlet pipe 6, a first smoke outlet 51 for discharging smoke out of the shell 1 and a second smoke outlet 52 corresponding to an air inlet channel of the air inlet pipe are arranged on the smoke exhaust pipe 5, and the second smoke outlet 52 enables the smoke discharged through the second smoke outlet 52 to return to the water heater through the air inlet pipe 6.

It should be noted that the air inlet pipe 6 is sleeved on the periphery of the smoke exhaust pipe 5, and the smoke exhaust pipe 5 and the air inlet pipe 6 are arranged at intervals; an air inlet channel is formed between the air inlet pipe 6 and the smoke exhaust pipe 5. The tail end of the smoke exhaust pipe 5 protrudes out of the tail end of the air inlet pipe 6, and the first smoke outlet 51 is positioned on the side wall of the protruding section of the smoke exhaust pipe protruding out of the air inlet pipe; the second smoke outlet 52 is located on the side wall of the overlapped section of the smoke exhaust pipe and the air inlet pipe, that is, the second smoke outlet 52 is located on the air inlet flow passage.

Specifically, the first smoke outlet 51 is located on a side wall of the tail of the smoke exhaust pipe. The air inlet is located on the side wall of the air inlet pipe.

In addition, the housing 1 is a closed structure, and the housing 1 and the air inlet pipe 6 are connected in a sealing manner. Thus, air required for combustion enters only through the air inlet pipe 6, and smoke is discharged only through the smoke exhaust pipe 5.

The fume extractor comprises: with the collection petticoat pipe that heat exchanger 3 is connected, and establish fan 4 on the collection petticoat pipe, the spiral case of fan with discharge fume 5 and connect.

Further, an electric control air valve for controlling the opening degree of the second smoke outlet is arranged on the second smoke outlet 52, and the electric control air valve is connected with a control device of the water heater.

The second smoke outlet 52 is provided with a gas flow sensor for detecting the smoke flow of the second smoke outlet, and the gas flow sensor is connected with a control device of the water heater.

The embodiment provides a low nitrogen water heater based on flue gas self-loopa, its concrete theory of operation is: the air required by combustion and the smoke generated by combustion are discharged or obtained through the integrated smoke exhaust pipe and the air inlet pipe, the gas is injected to the combustor 2 through the gas nozzle 21 to be combusted, the smoke generated by combustion is discharged through the fan 4 positioned above the water heater and is discharged out of the water heater through the smoke exhaust pipe 5 connected with the fan 4, when the smoke passes through the tail end of the smoke exhaust pipe, one part of the smoke is directly discharged through the first smoke outlet extending out, the other part of the smoke is discharged into the air inlet channel through the second smoke outlet positioned in the air inlet channel, the part of the smoke and the air flow back into the water heater together, the oxygen in the combustion-supporting air is diluted, the temperature of the inlet air is also improved, after the smoke pipe is subjected to backflow mixing, the concentration and the temperature distribution of the combustion-supporting gas are more uniform, no local high-temperature smoke exists, stable combustion is facilitated, and the oxygen content of the combustion-supporting air is effectively reduced, the reduction of combustion peak value is realized, and NOx can be effectively reduced. The fan is a direct-current variable speed fan, the wind speed can be adjusted according to the load, the negative pressure of the internal flow channel changes along with the load change, the amount of the returned smoke changes along with the load change, the air amount required by combustion is accurately matched, and the optimal combustion state is ensured. Meanwhile, the structure can be matched with a thick-thin combustor for use, NOx is reduced by various measures, and the emission concentration of the flue gas is reduced to an ideal level.

It will be appreciated by those skilled in the art from the foregoing description of construction and principles that the utility model is not limited to the specific embodiments described above, and that modifications and substitutions based on the teachings of the art may be made without departing from the scope of the utility model as defined by the appended claims and their equivalents. The details not described in the detailed description are prior art or common general knowledge.

Claims

1. A low nitrogen water heater based on flue gas self-circulation, comprising: the device comprises a shell, a combustor, a heat exchanger and a smoke exhaust device which are arranged in the shell, a smoke exhaust pipe connected with the smoke exhaust device, and an air inlet pipe for supplementing air to the combustor; the smoke exhaust device comprises a shell, an air inlet pipe, a smoke exhaust pipe, a first smoke outlet and a second smoke outlet, wherein the air inlet pipe and the smoke exhaust pipe are coaxially arranged on the shell, the air inlet pipe is provided with an air inlet, the smoke exhaust pipe is provided with a first smoke outlet and a second smoke outlet, the first smoke outlet and the second smoke outlet are used for discharging smoke out of the shell, the second smoke outlet corresponds to an air inlet channel of the air inlet pipe, and the smoke exhausted through the second smoke outlet flows back into the combustor through the air inlet pipe.

2. The low-nitrogen water heater based on the flue gas self-circulation is characterized in that the air inlet pipe is sleeved on the periphery of the smoke exhaust pipe, and the smoke exhaust pipe and the air inlet pipe are arranged at intervals; an air inlet channel is formed between the smoke exhaust pipe and the air inlet pipe.

3. The low-nitrogen water heater based on the flue gas self-circulation as claimed in claim 1 or 2, wherein the tail end of the smoke exhaust pipe protrudes out of the tail end of the air inlet pipe; the second smoke outlet is positioned on the side wall of the overlapped section of the smoke exhaust pipe and the air inlet pipe, and the first smoke outlet is positioned on the side wall of the smoke exhaust pipe protruding out of the air inlet pipe section.

4. The low-nitrogen water heater based on flue gas self-circulation according to claim 3, wherein the air inlet is located on the side wall of the air inlet pipe.

5. The low-nitrogen water heater based on the self-circulation of the flue gas as claimed in claim 1, wherein the housing is of a closed structure, and the housing is hermetically connected with the air inlet pipe.

6. The low-nitrogen water heater based on flue gas self-circulation according to claim 1, characterized in that the smoke exhaust device comprises: and the volute of the fan is connected with the smoke exhaust pipe.

7. The low-nitrogen water heater based on flue gas self-circulation of claim 6, wherein the fan is a direct current variable speed fan, and the direct current variable speed fan is connected with a control device of the water heater.

8. The low-nitrogen water heater based on the flue gas self-circulation is characterized in that an electric control air valve used for controlling the opening degree of the second smoke outlet is arranged on the second smoke outlet and connected with a control device of the water heater.

9. The low-nitrogen water heater based on the flue gas self-circulation is characterized in that a gas flow sensor for detecting the smoke flow of the second smoke outlet is arranged on the second smoke outlet, and the gas flow sensor is connected with a control device of the water heater.