Upward-drawing type rich-lean fire grate, burner and gas water heater

Abstract

The utility model discloses an upward-drawing type rich-lean fire grate, a burner and a gas water heater. The updraft type dense-thin fire grate comprises a fire grate body, a first injection pipe and a second injection pipe are arranged on the fire grate body, a distribution flow channel and an installation opening are further formed in the fire grate body, the installation opening, the distribution flow channel and the first injection pipe are sequentially communicated, an air outlet part is formed in the tail of the second injection pipe, and a plurality of air outlet holes are formed in the air outlet part; the opening areas of the multiple air outlet holes are in the trend of decreasing in the flowing direction of air flow in the second injection pipe. The side cover plate is arranged on the fire grate main body and covers the air outlet hole, and a dense flame opening is formed between the side cover plate and the fire grate main body; a plurality of light flame ports are formed in the inner core piece; wherein the inner core piece is arranged in the mounting opening. The flame stabilizing effect is optimized, so that the flame combustion stability is improved, and the combustion noise is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of household appliances, and particularly relates to an up-drawing type thick-thin fire grate, a burner and a gas water heater. BACKGROUND

[0002] At present, water heaters are commonly used household appliances in people's daily life. Water heaters are divided into types such as gas water heaters and electric water heaters, among which, the gas water heater is widely used due to its convenient use. A conventional gas water heater usually comprises a fan, a burner, a combustion chamber and a heat exchanger, etc. The burner burns gas in the combustion chamber to heat the water flowing through the heat exchanger.

[0003] According to the installation position of the fan, the gas water heater is divided into a down-drum type gas water heater and an up-drawing type gas water heater. For the up-drawing type gas water heater, the fan is arranged at the top of the heat exchanger. Under the action of the fan, a negative pressure is formed in the burner to realize the suction of external air into the burner for combustion. For example, a gas water heater and its combustion device and thick-thin fire grate are disclosed in Chinese Patent Publication No. CN 117824144A. The thick-thin fire grate is provided with two air inlets to meet the flow requirements of thick and thin mixed gas. During the transportation of the thick mixed gas, the uneven distribution of the gas leads to a large difference in the flame height of the thick flame at different positions of the thick-thin fire grate, and the flame stabilizing effect of the thick flame on the thin flame is greatly reduced, so that the problem of flame separation or unstable flame burning and obvious combustion noise is easily caused. In view of this, how to design a technology for optimizing the flame stabilizing effect to improve the flame burning stability and reduce the combustion noise is a technical problem to be solved by the present application. CONTENT OF THE PRESENT INVENTION

[0004] The present application provides an up-drawing type thick-thin fire grate, a burner and a gas water heater, which realizes the optimization of the flame stabilizing effect to improve the flame burning stability and reduce the combustion noise.

[0005] To achieve the above technical purpose, the present application adopts the following technical solutions:

[0006] In one aspect, the present application provides an up-drawing type thick-thin fire grate, comprising:

[0007] a fire grate main body, a first ejector pipe and a second ejector pipe are arranged on the fire grate main body, a distribution flow channel and a mounting port are further arranged in the fire grate main body, the mounting port, the distribution flow channel and the first ejector pipe are sequentially communicated, a tail portion of the second ejector pipe forms an air outlet portion, a plurality of air outlet holes are arranged on the air outlet portion; the opening areas of the plurality of air outlet holes present a decreasing trend along the direction of airflow flowing in the second ejector pipe;

[0008] A side cover plate is arranged on the fire grate body and covers the air outlet holes, and a dense flame port is formed between the side cover plate and the fire grate body;

[0009] An inner core member is arranged with a plurality of light flame ports;

[0010] The inner core member is arranged in the mounting port.

[0011] In an embodiment of the present application, the plurality of air outlet holes are divided into at least one first through hole and at least one second through hole, and the opening area of the first through hole is greater than that of the second through hole;

[0012] The first through hole and the second through hole are arranged in sequence along the direction of airflow in the second ejector pipe.

[0013] In an embodiment of the present application, the first through hole is a strip-shaped hole, and the strip-shaped hole extends along the direction of airflow in the second ejector pipe.

[0014] In an embodiment of the present application, each first through hole and each second through hole respectively includes a plurality of air passage sub-holes;

[0015] The number of air passage sub-holes per unit area in the region of the first through hole is greater than that in the region of the second through hole.

[0016] In an embodiment of the present application, a plurality of air passage sub-holes are arranged in sequence along the direction of airflow in the second ejector pipe.

[0017] In an embodiment of the present application, a plurality of air outlet holes are arranged in sequence from top to bottom in the direction of airflow in the second ejector pipe.

[0018] In an embodiment of the present application, the inner surface of the side cover plate is further provided with a flow guide protrusion; the lower part of the flow guide protrusion has a first inclined part, a second inclined part and a straight part, and the straight part is connected between the first inclined part and the second inclined part; the first inclined part, the straight part and the second inclined part are arranged in sequence along the direction of airflow in the second ejector pipe.

[0019] The flow guide protrusion is arranged above the air outlet part;

[0020] The first inclined part is configured to guide the gas output by the air outlet hole to flow in the opposite direction of the airflow in the second ejector pipe,

[0021] The second inclined part is configured to guide the gas output by the air outlet hole to flow in the direction of the airflow in the second ejector pipe.

[0022] In an embodiment of the present application, the inner surface of the side cover plate is further provided with a plurality of vertical protrusions, which abut against the fire grate body;

[0023] And / or, the inner surface of the side cover plate is provided with the transverse protrusions, which form a gap with the fire grate body.

[0024] In another aspect, an embodiment of the present application further provides a burner, comprising a shell, a plurality of first air inlets and a plurality of second air inlets are arranged on the side of the shell, and a ventilation opening is arranged on the bottom of the shell, and further comprising the above-mentioned dense and lean fire grate.

[0025] A plurality of the dense and lean fire grates are arranged side by side and arranged in the shell above the ventilation opening, the first injection pipe of the dense and lean fire grate is in communication with the corresponding first air inlet, and the second injection pipe of the dense and lean fire grate is in communication with the corresponding second air inlet.

[0026] In another aspect, an embodiment of the present application further provides a gas water heater, comprising a shell, a heat exchanger and a fan, and further comprising the above-mentioned burner; the heat exchanger, the fan and the burner are arranged in the shell, and the fan, the heat exchanger and the burner are arranged in sequence from top to bottom.

[0027] Compared with the prior art, the beneficial effects at least include:

[0028] By forming a plurality of air outlet holes at the tail of the second injection pipe, and along the flow direction of the airflow in the second injection pipe, the opening area of the air outlet hole presents a decreasing trend, the flow area of the dense mixture in the air outlet part of the second injection pipe is effectively increased, since the fan is used to draw air and the negative pressure in the burner is used to realize the flow of the mixture, the opening area of each air outlet hole on the air outlet part changes from large to small, which can ensure that the air resistance of the dense mixture flowing into the air outlet part is small, thereby effectively reducing the resistance of the gas flowing in the second injection pipe, improving the flow of the dense mixture, and ensuring the flame stability of the dense flame; in addition, the air outlet hole area at the head position of the air outlet part is the largest, which ensures that the total air outlet amount of the dense mixture flowing into the second injection pipe is sufficient, thereby ensuring that the air outlet amount of the dense flame port at different positions of the dense and lean fire grate is uniformly distributed, and ensuring that the dense flame port at each position can uniformly and effectively pull the lean flame generated by the lean flame port on the inner side to improve the combustion effect and realize the optimization of the flame stability effect to improve the flame combustion stability; at the same time, since the occurrence rate of the lean flame separation is reduced, the flame combustion stability can be ensured, and the combustion noise is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0030] Figure 1 It is a structural schematic view of an embodiment of the gas heater of the present application.

[0031] Figure 2 It is Figure 1 It is a structural schematic view of the thick and thin fire row.

[0032] Figure 3 It is Figure 2 It is an explosion view of the thick and thin fire row.

[0033] Figure 4 It is Figure 3 It is a structural schematic view of the thick and thin fire row.

[0034] Figure 5 It is Figure 3 It is a structural schematic view of the thick and thin fire row.

[0035] Figure 6 It is a structural schematic view of an embodiment of the gas heater of the present application.

[0036] Reference signs:

[0037] 1, thick and thin fire row; 11, fire row body; 12, side cover plate; 13, inner core piece;

[0038] 111, first injection pipe; 112, second injection pipe; 113, distribution flow channel; 114, mounting port;

[0039] 121, vertical protrusion; 122, transverse protrusion; 123, flow guide protrusion;

[0040] 1231, first inclined portion; 1232, second inclined portion; 1233, flat portion;

[0041] 2, shell; 21, first air inlet; 22, second air inlet. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0043] It should be noted that, in the description of the present application, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the direction or positional relationship of the terms based on the direction or positional relationship shown in the drawings, which is merely for the convenience of description, and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0044] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "below" the second feature can include the direct contact of the first and second features, or can include the contact of the first and second features through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes the first feature directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes the first feature directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0046] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0047] A gas water heater is a type of water heater that uses gas as its primary energy source. It produces hot water by transferring the high-temperature heat generated by the combustion of gas to cold water flowing through a heat exchanger.

[0048] Gas water heaters typically include an outer casing, as well as components such as a burner, heat exchanger, fan, and shroud housed within the casing.

[0049] In this process, the gas is delivered to the burner, where it is ignited by an ignition device, so that the burner can burn the delivered gas and generate heat.

[0050] The heat exchanger is equipped with heat exchange tubes. One end of the heat exchange tubes is connected to the water supply pipe, and the other end of the heat exchange tubes is connected to a shower head or faucet.

[0051] The heat generated by the burner burning the gas is used to heat the heat exchange tubes, thereby raising the temperature of the water inside the heat exchange tubes to form hot water.

[0052] When a gas water heater is working, cold water supplied by the water supply pipe flows into the heat exchange tube, and is then heated into hot water by the heat source generated by the burner. The hot water then flows out from the shower head or faucet through the hot water valve for the user's use.

[0053] At the same time, when the gas water heater is working, the fan is powered on and running simultaneously. Under the action of the fan, the flue gas generated by the burner is discharged outdoors.

[0054] Example 1, as Figures 1-5 As shown, an embodiment of this application provides a burner including a rich-lean combustor 1 and a housing 2, with multiple rich-lean combustors 1 installed in the housing 2.

[0055] The burner 1 typically includes: burner body 11, side cover plate 12, and inner core component 13.

[0056] The fire row body 11 is provided with a first ejector pipe 111 and a second ejector pipe 112, and is further provided with a distribution flow channel 113 and a mounting port 114, the mounting port 114, the distribution flow channel 113 and the first ejector pipe 111 are sequentially communicated, a tail of the second ejector pipe 112 forms an air outlet part, and a plurality of air outlet holes 1121 are arranged on the air outlet part; the opening areas of the plurality of air outlet holes 1121 gradually decrease along the air flow direction in the second ejector pipe 112.

[0057] The side cover plate 12 is arranged on the fire row body 11 and covers the air outlet holes 1121, and a dense flame flow channel is formed between the side cover plate 12 and the fire row body 11, and the dense flame flow channel has a dense flame port.

[0058] The inner core member 13 is arranged in the mounting port 114 and is provided with a plurality of light flame ports.

[0059] In order to meet the air intake requirement of the dense and light fire row, a plurality of first air inlets 21 and a plurality of second air inlets 22 are arranged on the shell 2, the first air inlets 21 can meet the input of light mixed gas of the first ejector pipe 111, and the second air inlets 22 can meet the input of dense mixed gas of the second ejector pipe 112. The light mixed gas transported by the first ejector pipe 111 is output at the light flame port and burns to form light flame, and the dense mixed gas transported by the second ejector pipe 112 is output at the dense flame port and burns to form dense flame. The bottom of the shell 2 is provided with a ventilation port to meet the air intake requirement of air being sucked into the shell 2.

[0060] The tail of the second ejector pipe 112 forms an air outlet part, and a plurality of air outlet holes 1121 are arranged on the air outlet part; the opening areas of the plurality of air outlet holes 1121 gradually decrease along the air flow direction in the second ejector pipe 112.

[0061] Specifically, the second ejector pipe 112 is used for transporting dense mixed gas, and generally, the pipe diameter of the second ejector pipe 112 is smaller than that of the first ejector pipe 111, so that the air resistance in the second ejector pipe 112 is larger. At the same time, since the fan adopts the upper suction mode, the negative pressure formed in the shell 2 is used to suck air and mix with gas, in order to improve the air intake amount of the dense mixed gas in the second ejector pipe 112, the opening areas of the plurality of air outlet holes 1121 are gradually increased in the opposite direction of the air flow in the second ejector pipe 112.

[0062] Thus, for the mixed gas sucked into the second ejector pipe 112, the mixed gas can reduce the air resistance generated by the second ejector pipe 112 in the flow process due to the large opening area of the gas outlet hole 1121 at the head position of the gas outlet part, so that the dense mixed gas sucked by the second ejector pipe 112 can smoothly enter between the side cover plate 12 and the fire grate main body 11 through each gas outlet hole 1121.

[0063] Since the opening area of the plurality of gas outlet holes 1121 gradually increases in the opposite direction of the gas flow, the air resistance of the second ejector pipe 112 is reduced, which is more conducive to improving the air intake and air intake speed, and can ensure the uniformity of the distribution of dense mixed gas of different dense flame ports to improve the stability of combustion.

[0064] By forming a plurality of gas outlet holes at the tail of the second ejector pipe, and the opening area of the gas outlet hole decreases along the direction of the gas flow in the second ejector pipe, the flow area of the dense mixed gas in the gas outlet part of the second ejector pipe is effectively increased. Since the fan is used to draw air and the negative pressure in the burner is used to realize the flow of the mixed gas, the opening area of each gas outlet hole on the gas outlet part changes from large to small, which can ensure that the air resistance of the dense mixed gas flowing into the gas outlet part is small, thereby effectively reducing the resistance of the gas sucked by the second ejector pipe, improving the flow of the dense mixed gas delivered to the dense flame port, and thereby enhancing the stability of the dense flame to the light flame. In actual use, the resistance of the dense gas flowing in the second ejector pipe can be effectively reduced, the flow of the dense mixed gas can be improved, and the stability of the dense flame can be ensured. In addition, the opening area of the gas outlet hole at the head position of the gas outlet part is the largest, which can ensure that the total gas outlet amount of the dense mixed gas flowing to the second ejector pipe is sufficient, thereby ensuring that the gas outlet amount of the dense flame port at different positions of the dense and light fire grate is uniformly distributed, and ensuring that the dense flame port at each position can uniformly and effectively pull the light flame generated by the inner light flame port, so as to improve the combustion effect and realize the optimization of the flame stability effect to improve the flame combustion stability. At the same time, since the occurrence rate of the light flame separation is reduced, the flame combustion stability can be ensured, and the combustion noise is reduced.

[0065] In an embodiment, in order to realize that the opening area of the plurality of gas outlet holes 1121 increases in the opposite direction of the gas flow, the following structure can be adopted.

[0066] The plurality of gas outlet holes 1121 are divided into at least one first through hole and at least one second through hole, and the opening area of the first through hole is larger than that of the second through hole; wherein the first through hole and the second through hole are arranged in sequence along the direction of the gas flow in the second ejector pipe 112.

[0067] Specifically, the first through hole is a strip-shaped hole, and the strip-shaped hole extends along the direction of airflow in the second ejector pipe 112. The strip-shaped hole design can increase the opening area of the first through hole and prolong the air supply path of the first through hole.

[0068] Alternatively, each of the first through holes and each of the second through holes respectively comprises a plurality of ventilation sub-holes; wherein the number of the ventilation sub-holes per unit area in the region where the first through hole is located is greater than the number of the ventilation sub-holes per unit area in the region where the second through hole is located.

[0069] In addition, the plurality of ventilation sub-holes are arranged in sequence along the direction of airflow in the second ejector pipe 112.

[0070] In another embodiment of the present application, the cross-sectional area of the airflow flow path of the air outlet part in the second ejector pipe 112 is smaller than the area of the ejecting port of the second ejector pipe 112.

[0071] Specifically, in order to increase the airflow output speed of the air outlet part, the cross-sectional area of the airflow flow path of the air outlet part is small, so that the airflow flow rate output from the air outlet hole 1121 is increased. At the same time, the change of the decreasing trend of the opening area of the different air outlet holes 1121 along the airflow direction can appropriately increase the air intake while ensuring the flow rate of the airflow.

[0072] In an embodiment, along the direction of airflow in the second ejector pipe, the plurality of air outlet holes are arranged in sequence from top to bottom in an inclined manner.

[0073] Specifically, for the air outlet part, it extends in an inclined manner from top to bottom along the direction of airflow in the second ejector pipe 112, and the included angle between the inclined extension direction of the air outlet part and the air inlet direction of the second ejector pipe 112 is 10° to 20°.

[0074] Specifically, the air outlet part adopts the above-mentioned included angle design, which improves the local resistance caused by the sudden change of the cross section of the air outlet part, so that the rich mixed gas still has a high speed when it flows out of the air outlet hole 1121, thereby providing sufficient energy for the subsequent development of the rich mixed gas in the rich flame flow channel. At the same time, the slow inclination of the inclined surface also increases the volume of the inlet structure of the rich mixed gas, so that the amount of rich mixed gas flowing through the air outlet hole 1121 at the same time is increased, and the flow rate is accelerated, which is beneficial to the subsequent diffusion of the rich mixed gas.

[0075] In an embodiment of the present application, the inner surface of the side cover plate is further provided with a flow guide protrusion 123; the lower part of the flow guide protrusion has a first inclined part 1231, a second inclined part 1232 and a flat part 1233, and the flat part is connected between the first inclined part and the second inclined part; along the direction of airflow in the second ejector pipe, the first inclined part, the flat part and the second inclined part are arranged in sequence.

[0076] The flow guide protrusion is arranged above the air outlet portion;

[0077] The first inclined portion is configured to guide the gas output by the air outlet hole to flow in a direction opposite to the flow direction of the gas in the second draft tube,

[0078] The second inclined portion is configured to guide the gas output by the air outlet hole to flow in the flow direction of the gas in the second draft tube.

[0079] Specifically, the flow guide protrusion 123 is arranged obliquely above the air outlet portion in the flow direction of the gas in the second draft tube 112, so that the dense mixed gas output from each air outlet hole 1121 flows through the flow guide protrusion 123 to guide the gas flow through the flow guide protrusion 123.

[0080] Part of the gas is blocked by the first inclined portion 1231 of the flow guide protrusion 123 and flows to the dense flame port on the second draft tube 112, and the remaining part of the gas is guided through the flat portion 1233 and guided to the dense flame port distributed away from the second draft tube 112 through the second inclined portion 1232.

[0081] The first inclined portion 1231 extends from bottom to top in a direction opposite to the flow direction of the gas in the second draft tube 112, and the second inclined portion 1232 extends from bottom to top in the flow direction of the gas in the second draft tube 112.

[0082] In one embodiment, the inner surface of the side cover plate 12 is further provided with a plurality of vertical protrusions 121, which abut against the fire grate body 11.

[0083] The inner surface of the side cover plate 12 is provided with transverse protrusions 122, which form a gap with the fire grate body.

[0084] Specifically, the vertical protrusions 121 are added in the dense mixed gas mixing area formed between the side cover plate 12 and the fire grate body 11, and a vertical channel is formed between two adjacent vertical protrusions 121 to guide the dense mixed gas to flow to the dense flame port.

[0085] In addition, the lateral protrusions 122 provided on the side cover plate 12 can block and uniformly disperse the rich mixture flowing to the rich flame port. During the process of the rich mixture flowing to the rich flame port, when the rich mixture flows to the lateral protrusions 122, the lateral protrusions 122 can block the rich mixture to a certain extent, so that part of the rich mixture directly flows to the rich flame port through the space between the lateral protrusions 122 and the fire grate body, and the remaining part of the rich mixture is guided to diffuse along the lateral protrusions 122 and then flows to the rich flame port through the space between the lateral protrusions 122 and the fire grate body, thereby uniformly distributing the rich mixture and ensuring the uniformity of the airflow of the rich flame port. In addition, the problem of excessive air flow of the rich flame port adjacent to the air outlet part due to the limitation of the position of the air outlet part is solved, thereby realizing the stability of the rich flame combustion and improving the flame stabilizing ability of the rich flame to the weak flame.

[0086] In the second embodiment, as shown in the accompanying drawings, the application further provides a gas water heater, which comprises: Figure 6

[0087] a casing 100, wherein the casing is further provided with a water inlet pipe 101 and a water outlet pipe 102;

[0088] a heat exchanger 200, wherein the heat exchanger is provided with a heat exchange flow channel;

[0089] a burner 300, wherein the burner is the burner in the first embodiment;

[0090] a fan 400;

[0091] wherein the heat exchanger, the fan and the burner are arranged in the casing, and the fan, the heat exchanger and the burner are arranged in sequence from top to bottom.

[0092] The above embodiments are only used to illustrate the technical solutions of the application, but not to limit the application; although the application has been described in detail with reference to the foregoing embodiments, the technical solutions recorded in the foregoing embodiments can still be modified by those skilled in the art, or some technical features can be replaced by equivalent features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed by the application.​

Claims

1. A top-drawing type concentration / diluted heat exchanger, characterized in that, include: The main body of the fire duct is provided with a first ejector tube and a second ejector tube. The main body of the fire duct is also provided with a distribution channel and an installation port. The installation port, the distribution channel and the first ejector tube are connected in sequence. The tail end of the second ejector tube forms an air outlet. The air outlet is provided with a plurality of air outlet holes. The opening area of ​​the plurality of air outlet holes tends to decrease along the airflow direction in the second ejector tube. A side cover plate is provided on the main body of the fire briquette and covers the air outlet. A dense flame port is formed between the side cover plate and the main body of the fire briquette. An inner core component, wherein multiple light flame ports are provided on the inner core component; The inner core component is disposed in the mounting port.

2. The top-drawing concentration / dilute firebox according to claim 1, characterized in that, Along the airflow direction in the second ejector tube, the plurality of air outlets are arranged in a series of inclined positions from top to bottom.

3. The top-drawing concentration / dilute heat exchanger according to claim 1, characterized in that, The inner surface of the side cover plate is also provided with a flow guiding protrusion; the lower part of the flow guiding protrusion has a first inclined part, a second inclined part and a straight part, and the straight part is connected between the first inclined part and the second inclined part; along the airflow direction in the second ejector tube, the first inclined part, the straight part and the second inclined part are arranged in sequence; The guide protrusion is arranged above the air outlet; The first inclined portion is configured to guide the gas output from the gas outlet to flow in the opposite direction to the gas flow in the second ejector tube, and the second inclined portion is configured to guide the gas output from the gas outlet to flow in the direction of the gas flow in the second ejector tube.

4. The top-drawing concentration / dilute firebox according to claim 1, characterized in that, The inner surface of the side cover plate is also provided with multiple vertical protrusions, which abut against the main body of the fire briquette. And / or, a transverse protrusion is provided on the inner surface of the side cover plate, and the transverse protrusion forms a gap with the fire vent body.

5. The top-drawing concentration / dilute burner according to any one of claims 1-4, characterized in that, The plurality of air outlets are divided into at least one first through hole and at least one second through hole, wherein the opening area of ​​the first through hole is larger than the opening area of ​​the second through hole; The first through hole and the second through hole are arranged sequentially along the airflow direction in the second ejector tube.

6. The top-extraction concentration / dilute heat exchanger according to claim 5, characterized in that, The first through hole is a strip-shaped hole, which extends along the airflow direction in the second ejector tube.

7. The top-drawing concentration / dilute heat exchanger according to claim 5, characterized in that, Each of the first through holes and each of the second through holes includes a plurality of vent sub-holes; The number of venting sub-holes per unit area in the region where the first through hole is located is greater than the number of venting sub-holes per unit area in the region where the second through hole is located.

8. The top-drawing concentration / dilute heat exchanger according to claim 7, characterized in that, The plurality of vent holes are arranged sequentially along the airflow direction in the second ejector tube.

9. A burner, comprising a housing, wherein a plurality of first air inlets and a plurality of second air inlets are provided on the side of the housing, and a vent is provided at the bottom of the housing, characterized in that, It also includes the top-extraction concentration / dilute flask as described in any one of claims 1-8; Multiple concentration-dilute combustors are arranged side by side in the housing and located above the vent. The first ejector tube of each concentration-dilute combustor is connected to the corresponding first air inlet, and the second ejector tube of each concentration-dilute combustor is connected to the corresponding second air inlet.

10. A gas water heater, comprising a casing, a heat exchanger, and a fan, characterized in that, It also includes the burner as described in claim 9; the heat exchanger, the fan and the burner are disposed in the housing, and the fan, the heat exchanger and the burner are arranged sequentially from top to bottom.

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