CN112682787A

CN112682787A - Combustion heat exchange assembly and gas water heater

Info

Publication number: CN112682787A
Application number: CN202010487273.9A
Authority: CN
Inventors: 钱晓林; 梁泽锋; 曲绍鹤; 李忠华
Original assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Priority date: 2019-10-17
Filing date: 2020-05-30
Publication date: 2021-04-20
Anticipated expiration: 2040-05-30
Also published as: CN112682790B; CN112682789A; CN112682788B; CN212618285U; CN112682780A; CN112682788A; CN112682792A; WO2021244493A1; CN112682781A; CN112682790A; CN112682784A; CN112682787B; CN112682791A; CN213272606U; CN112682782A; CN212618288U; CN212618287U; CN212618286U; CN112682783B; CN212618283U

Abstract

The invention discloses a combustion heat exchange assembly and a gas water heater, wherein the combustion heat exchange assembly comprises a heat exchange assembly and a burner, the heat exchange assembly comprises two heat exchangers and a shell assembly formed with a heat exchange chamber, the two heat exchangers are arranged in the heat exchange chamber, and one of the heat exchangers is used for allowing external air to pass through; the combustor has high temperature air combustion chamber, and in the heat exchange chamber was located to the combustor, the high temperature air combustion chamber was used for carrying out high temperature air combustion reaction to pass through two heat exchangers in proper order with burning exhaust flue gas. The invention discloses a combustion heat exchange assembly for realizing high-temperature air combustion and a gas water heater.

Description

Combustion heat exchange assembly and gas water heater

This application claims priority from chinese patent application entitled "burner and gas water heater" filed on 17/10/2019, application No. 201910992986.8, the entire contents of which are incorporated herein by reference.

Technical Field

The invention relates to the technical field of gas water heaters, in particular to a combustion heat exchange assembly and a gas water heater.

Background

High temperature air combustion (high temperature air combustion) is called MILD and deep low oxygen dilution combustion, and is called a novel combustion mode for short, namely MILD combustion. The main characteristics of the combustion are as follows: the chemical reactions mainly take place in a high temperature, low oxygen environment, with the reactants at a temperature above their natural temperature and the maximum temperature rise during combustion below their natural temperature, with the oxygen volume fraction being diluted by the combustion products to an extremely low concentration, typically 3% to 5%. Compared with conventional combustion, in the combustion state, the pyrolysis of fuel is inhibited, the flame thickness is thickened, and the flame front surface disappears, so that the temperature of the whole hearth is very uniform during the combustion, the generation of thermal nitrogen oxides is reduced, and the emission of pollutants NOx and CO is greatly reduced.

Although high temperature air combustion has many of the above advantages, it is not currently used in domestic life.

Disclosure of Invention

The invention mainly aims to provide a combustion heat exchange assembly with a high-temperature air combustion function and a gas water heater.

To achieve the above object, the present invention provides a combustion heat exchange assembly, comprising:

the heat exchange assembly comprises two heat exchangers and a shell assembly formed with a heat exchange chamber, the two heat exchangers are arranged in the heat exchange chamber, and one of the heat exchangers is used for allowing outside air to pass through; and the number of the first and second groups,

the combustor, the combustor has the high temperature air combustion chamber, the combustor is located in the heat exchange chamber, the high temperature air combustion chamber is used for carrying out the high temperature air combustion reaction to pass through combustion exhaust flue gas in proper order two heat exchangers.

In an embodiment, the two heat exchangers include a first heat exchanger and a second heat exchanger to pass outside air;

the first heat exchanger is arranged on one side of the combustor, and the second heat exchanger is arranged on one side, back to the combustor, of the first heat exchanger.

In one embodiment, the burner is located vertically below the two heat exchangers.

In one embodiment, a flue gas channel communicated with the high-temperature air combustion chamber is formed between the outer wall of the combustor and the chamber wall of the heat exchange chamber, and the communication port of the flue gas channel and the high-temperature air combustion chamber is arranged far away from the two heat exchangers.

In one embodiment, the shell assembly is provided with an exhaust port communicated with the heat exchange chamber, and the exhaust port is arranged on one side of the second heat exchanger, which faces away from the combustor.

In addition, to achieve the above object, the present invention also provides a gas water heater comprising:

the combustion heat exchange assembly as described above;

the air inlet assembly is used for sucking external air, heating the external air to a preset target temperature through one of the heat exchangers and then conveying the external air to the high-temperature air combustion chamber; and the number of the first and second groups,

and the gas component is used for jetting gas to the high-temperature air combustion chamber so as to enable the combustor to perform high-temperature air combustion.

In one embodiment, the air intake assembly is used for sucking external air, heating the external air to a preset target temperature through the first heat exchanger, and then delivering the external air to the high-temperature air combustion chamber.

In one embodiment, the air intake assembly is provided with a plurality of air supply outlets, wherein:

the first heat exchanger is arranged across the heat exchange chamber, and two air inlets are arranged at two ends of the first heat exchanger corresponding to the air inlets; alternatively, the first and second electrodes may be,

the first heat exchanger is arranged on one side of the heat exchange chamber, and a plurality of air inlets corresponding to the first heat exchanger are arranged; alternatively, the first and second electrodes may be,

the first heat exchanger is arranged around the circumference of the heat exchange chamber, and the air inlet is provided with a plurality of air inlets corresponding to the circumference of the first heat exchanger.

In one embodiment, the gas fired assembly has an injection port;

the injection port penetrates through the heat exchange chamber and the first heat exchanger in sequence and then is arranged in the high-temperature air combustion chamber.

In one embodiment, the injection port of the gas burner assembly is disposed through a middle portion of the first heat exchanger.

In an embodiment, the air intake assembly is provided with at least two air outlets, and the at least two air outlets are arranged at intervals in the circumferential direction of the injection port of the gas assembly.

In one embodiment, the gas water heater further comprises a heater and a controller, the controller is electrically connected with the heater, the controller is used for controlling the heater to heat the external air sucked by the air inlet assembly, and the heater is controlled to be turned off when the smoke exhausted by the burner passes through the corresponding heat exchanger.

In an embodiment, the gas water heater further comprises a valve body, the valve body is arranged on the gas assembly, and the valve body is used for opening the high-temperature air combustion chamber after the air inlet assembly conveys the external air heated to the preset target temperature to the high-temperature air combustion chamber so that the gas can enter the high-temperature air combustion chamber.

According to the technical scheme provided by the invention, after high-temperature air combustion is carried out in the high-temperature air combustion chamber, the generated smoke sequentially circulates to the two heat exchangers, and external air is heated through one heat exchanger, so that the original high-temperature preheating mode of the air inlet assembly can be assisted or replaced; and the tap water is heated by another heat exchanger. Wherein, produce the entrainment effect in the high temperature air combustion chamber for the high temperature flue gas backward flow realizes keeping warm on the one hand, makes the interior gas of high temperature air combustion chamber can the spontaneous combustion, and on the other hand dilutes the air, makes oxygen concentration be less than a definite value, realizes the homogeneous combustion.

Drawings

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

FIG. 1 is a schematic structural view of a first embodiment of a gas water heater provided by the present invention;

FIG. 2 is a schematic structural diagram of a second embodiment of a gas water heater provided by the present invention;

fig. 3 is a schematic structural diagram of a gas water heater according to a third embodiment of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				11	Heat exchanger	21	High-temperature air combustion chamber
111	First heat exchanger	3	Air inlet assembly
				112	Second heat exchanger	4	Gas component
12	Shell assembly	5	Return member
				121	Heat exchange chamber	51	Fluidic channel
13	Flue gas channel	52	Guide surface
				14	Smoke outlet	53	Main body segment
2	Burner with a burner head	6	Water pipe

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to design a novel burner by utilizing the combustion characteristic of high-temperature air and apply the novel burner to a gas water heater, so that the gas water heater can effectively reduce the emission of CO and NOx and reduce the noise of the gas water heater.

The combustion heat exchange assembly provided by the invention is suitable for gas water heaters, and related products and equipment such as gas wall-mounted furnaces and the like which use high-temperature hot water generated by gas combustion for household bathing, heating and the like.

Based on this, the gas water heater provided by the invention comprises a combustion heat exchange assembly, an air inlet assembly 3 and a gas assembly 4, wherein the combustion heat exchange assembly comprises a heat exchange assembly (not shown in the attached drawings), a combustor 2, the air inlet assembly 3 and the gas assembly 4. Specifically, the heat exchange assembly comprises a heat exchanger 11 and a shell assembly 12 formed with a heat exchange chamber 121, wherein the heat exchanger 11 is arranged in the heat exchange chamber 121; the combustor 2 forms a high-temperature air combustion chamber 21 with a gas inlet and a flue gas outlet, the combustor 2 is arranged in the heat exchange chamber 121, and flue gas discharged by combustion in the high-temperature air combustion chamber 21 passes through the heat exchanger 11; the air inlet component 3 is used for sucking external air, heating the external air to a preset target temperature and then conveying the external air to the high-temperature air combustion chamber 21; the gas combustion assembly 4 is used for injecting gas into the high-temperature air combustion chamber 21 for combustion by the combustor 2.

The high-temperature air combustion is mainly characterized in that: the chemical reaction needs to take place in a high temperature, low oxygen environment, with the reactants at a temperature above their auto-ignition temperature and the maximum temperature rise during combustion below their auto-ignition temperature, with the oxygen volume fraction being diluted to a very low concentration by the combustion products. Compared with conventional combustion, in the combustion state, the pyrolysis of fuel is inhibited, the flame thickness is thickened, and the flame front surface disappears, so that the temperature of the whole hearth is uniform, the combustion peak temperature is low, the noise is low, and the emission of pollutants NOx and CO is greatly reduced. However, achieving high temperature air combustion requires certain conditions: the oxygen concentration in most areas in the furnace is required to be ensured to be lower than a certain value, generally lower than 5% -10%, the gas is ensured to be fully combusted and uniformly combusted, the temperature is higher than the self-ignition point of the fuel, and the self-ignition is maintained.

It should be noted that, this embodiment realizes the entrainment high temperature flue gas and dilutes through high temperature preheated air and cooperation high-speed efflux, make gas and air misce bene in the high temperature air combustion chamber 21, the oxygen concentration of high temperature air combustion chamber 21 also can be balanced like this, and be less than a definite value, like this, not only the gas can obtain abundant burning during the burning, just so reduced the emission of pollutant, and, also can the burning in the high temperature air combustion chamber 21 is even, the problem of local combustion too flourishing and noise production can not appear. In addition, the backflow of high-temperature flue gas is realized through high-speed jet entrainment, the temperature of the high-temperature air combustion chamber 21 can be kept higher than the self-ignition point of fuel, and the combustion can be maintained as long as the fuel gas is continuously introduced.

In addition, the structure of the burner frame of the gas water heater with the high-temperature air combustion function provided by the invention can miniaturize the components for realizing the high-temperature air combustion, so that the gas water heater has more application space and value, and has low noise, sufficient combustion and small pollution of discharged waste gas.

It can be understood that, can heat the air to the target temperature and realize high temperature preheated air through air inlet subassembly 3, and carry out entrainment effect with the gas cooperation of gas subassembly 4 access, make and form injection combustion area and flue gas backward flow district in high temperature air combustion chamber 21, make partial high temperature flue gas strong circulation in high temperature air combustion chamber 21, then fully dilute gas and air, form lower oxygen concentration, reduce the combustion reaction speed, the higher temperature of high temperature air combustion chamber 21 can be maintained simultaneously to the endless high temperature flue gas, guarantee that the temperature is higher than the spontaneous combustion point of fuel, realize the spontaneous combustion of fuel, then do not need the ignition. As such, the present embodiment satisfies the condition of high-temperature air combustion (mld combustion): high-temperature preheating air is matched with high-speed jet flow to realize entrainment of high-temperature flue gas and dilution of fuel gas and air, so that the oxygen concentration is lower than a certain value, and the temperature is higher than the self-ignition point of the fuel. The heat after combustion is transferred to a heat exchanger 11 for heat exchange to produce hot water. It should be noted that only air, only gas, or a mixture of air and gas may be used to perform the high-speed jet, but for the sake of understanding, the following description will be made by taking only gas as an example to perform the high-speed jet.

In the heat exchange assembly, the shell assembly 12 may be integrally formed or may be separately arranged, wherein when the shell assembly 12 is separately arranged, the separate assembly may be fixedly joined by screwing, bonding or fastening; the heat exchange chambers 121 are defined as an inner cavity enclosed by the housing component 12, and the number of the heat exchange chambers 121 can be one or more; the cross-section of the heat exchange chamber 121 may exhibit various shapes, for example, a circular shape, an oval shape, or a polygonal shape, according to actual requirements. The number of the heat exchangers 11 can be set to be one or more, wherein at least one of the heat exchangers 11 is used for connecting the water pipe 6, and the water pipe 6 is connected with cold water and exchanges heat under the action of the heat exchanger 11.

The air inlet component 3 comprises an air inlet main body, the air inlet main body is provided with an air inlet channel, at least part of the air inlet channel is arranged in the heat exchange chamber 121, the air inlet channel is provided with an air supply opening and an air outlet, the air outlet is communicated with the high-temperature air combustion chamber 21, and the air inlet channel can be provided with a fan and other structures to suck external air and supply air into the high-temperature air combustion chamber 21. Can heat the air to the target temperature and realize the high temperature of air and preheat through air inlet subassembly 3, wherein, the air temperature after the high temperature preheats can not be less than 600 degrees centigrade, and the high temperature air burning can be guaranteed at 600 to 1200 degrees centigrade to general control. Wherein, the target temperature can be reached by controlling the heating time, the heating power and the like. The air intake assembly 3 may further include a temperature measuring device (not shown in the drawings) disposed in the high temperature air combustion chamber 21 and near the air supply port of the air intake passage, for measuring whether the outside air entering the high temperature air combustion chamber 21 through the air intake passage reaches a preset target temperature.

The gas assembly 4 includes a gas main body, the gas main body is formed with a gas flow channel, the gas flow channel is at least partially disposed in the heat exchange chamber 121, and the gas flow channel has an air inlet and an injection port, the air inlet of the gas flow channel is used for connecting to an external gas pipeline, the injection port of the gas flow channel is communicated with the high temperature air combustion chamber 21, and is used for injecting gas into the high temperature air combustion chamber 21 through the injection port of the gas flow channel. The gas combustion assembly 4 may further include an ignition device for igniting the gas in the high temperature air combustion chamber 21 so that the gas ignites to form the above-described jet combustion zone. It should be noted that the injection speed of the gas injection pipe is usually predetermined and set by experiment, and then is not substantially changed, so that the oxygen concentration of the high temperature air combustion chamber 21 can be controlled by controlling the ratio of the gas and the air. Based on this theoretical basis, it is not difficult to specifically control the oxygen concentration of the high-temperature air combustion chamber 21, and the detailed description is omitted here.

Based on the above, referring to fig. 1, in order to optimize the performance of the gas water heater, in the first embodiment of the present invention, the heat exchange assembly is provided with two heat exchangers 11, wherein the two heat exchangers 11 are both disposed in the heat exchange chamber 121. The flue gas discharged by combustion in the high-temperature air combustion chamber 21 of the combustor 2 sequentially passes through the two heat exchangers 11; the air intake component 3 is used for sucking external air, heating the external air to a preset target temperature through one of the heat exchangers 11, and then conveying the external air to the high-temperature air combustion chamber 21; the gas combustion assembly 4 is still used to inject gas into the high temperature air combustion chamber 21 for combustion by the burner 2.

It can be understood that the air intake component 3 performs high-temperature preheating of external intake air, and realizes entrainment effect by matching with the fuel gas injected by the fuel gas component 4, thereby meeting the MILD combustion condition; the flue gas generated after combustion in the high-temperature air combustion chamber 21 sequentially flows to the two heat exchangers 11, and the external air continuously sucked into the air inlet assembly 3 is heated through one of the heat exchangers 11, so that the original high-temperature preheating mode of the air inlet assembly 3 can be assisted or replaced; and exchanges heat with the tap water through another heat exchanger 11. Thus, a practical gas water heater with high temperature air combustion (MILD combustion) function is realized.

In the first embodiment, the two heat exchangers 11 include the first heat exchanger 111 and the second heat exchanger 112; the first heat exchanger 111 is provided on the side of the burner 2, and the second heat exchanger 112 is provided on the side of the first heat exchanger 111 facing away from the burner 2. That is, the burner 2 is located on the same side of the first and

second heat exchangers

111 and 112, rather than being disposed between the first and

second heat exchangers

111 and 112. In this way, the flue gas generated by combustion in the high-temperature air combustion chamber 21 uniformly flows toward the first heat exchanger 111, so that the flue gas sequentially passes through the two heat exchangers 11. The unified circulation of flue gas can reduce the heat loss that the flue gas produced in the circulation process on the one hand, and on the other hand can realize that the flue gas carries out high temperature preheating to the outside air that circulates of one of them heat exchanger 11 department and the flue gas carries out the heat transfer to the running water that circulates of another one of them heat exchanger 11 department in step.

Further, in the first embodiment, the burner 2 is provided vertically below the two heat exchangers 11. That is, both heat exchangers 11 are located vertically above the burner 2. It can be understood that the density of the flue gas generated by combustion in the high-temperature air combustion chamber 21 is generally smaller than that of the air, so that the flue gas is lighter than the air, the combustor 2 is arranged at a lower position, the flue gas can float upwards along the vertical direction without additionally arranging a power structure for driving, the purpose of sequentially passing through the two heat exchangers 11 is achieved, the whole structure of the gas water heater is facilitated to be simplified, and the whole cost of the gas water heater is reduced.

It should be noted that the above does not limit the installation orientation of all the components of the burner 2, and only the connection between the high-temperature air combustion chamber 21 and the heat exchange chamber 121 in the burner 2 is required to be disposed on the same side of the two heat exchangers 11, so as to realize the circulation of the flue gas in one direction and sequentially pass through the two heat exchangers 11. Other components of the combustor 2 may be disposed between the two heat exchangers 11 or disposed on both sides of the two heat exchangers 11 according to actual needs.

Of course, in other embodiments, the burner 2 may also be disposed between the two heat exchange chambers 121, and in this case, a flow dividing member needs to be disposed at the outlet of the high temperature air combustion chamber 21, and the flow dividing member is used for dividing the flue gas generated by combustion in the high temperature air combustion chamber 21 to respectively face the two heat exchangers 11, so as to implement simultaneous heat exchange or sequential heat exchange of the two heat exchangers 11.

In view of the above, either one of the first heat exchanger 111 and the second heat exchanger 112 can be used for high-temperature preheating of the outside air passing through the air intake assembly 3, and the other one is used for heat exchange of the tap water passing through the water pipe 6; the first heat exchanger 111 is disposed closer to the burner 2 than the second heat exchanger 112, and since the flue gas generated by combustion in the high temperature air combustion chamber 21 inevitably carries heat, which may be lost during the transfer process, it can be understood that the heat exchange heat obtained at the first heat exchanger 111 is higher than the heat exchange heat obtained at the second heat exchanger 112 when the flue gas passes through the first heat exchanger 111 and the second heat exchanger 112 in sequence. The temperature of the air after high temperature preheating is required to be not lower than 600 degrees centigrade, which is much higher than the heat exchange requirement of the tap water in the water pipe 6, therefore, in the first embodiment, the air intake assembly 3 is used for sucking the external air, heating the air to the preset target temperature by the first heat exchanger 111, and then delivering the air to the high temperature air combustion chamber 21.

Next, in the above first embodiment, the air intake component 3 is provided with a plurality of air outlets, and one of the air outlets correspondingly forms one of the air intake channels. The specific arrangement of the air supply opening is related to the structure of the first heat exchanger 111, wherein, when the first heat exchanger 111 is in a longitudinal shape and the first heat exchanger 111 is arranged across the heat exchange chamber 121, two air supply openings can be arranged corresponding to two ends of the first heat exchanger 111, so that two formed air inlet channels are arranged corresponding to the main body of the first heat exchanger 111, and at the moment, the first heat exchanger 111 can act on the two air inlet channels simultaneously, thereby realizing synchronous high-temperature preheating of air circulating in all the air inlet channels; or, the first heat exchanger 111 is block-shaped, the first heat exchanger 111 is arranged at one side of the heat exchange chamber 121, and a plurality of air supply outlets are arranged at positions corresponding to the first heat exchanger 111, so that a plurality of formed air inlet channels are arranged corresponding to the main body of the first heat exchanger 111, and at this time, the first heat exchanger 111 can act on the plurality of air inlet channels at the same time, thereby realizing synchronous high-temperature preheating of air circulating in all the air inlet channels; or, the first heat exchanger 111 is annularly arranged, the first heat exchanger 111 is circumferentially arranged around the heat exchange chamber 121, and the air supply outlets are circumferentially arranged corresponding to the first heat exchanger 111, so that a plurality of formed air inlet channels are arranged corresponding to the main body of the first heat exchanger 111, and at the moment, the first heat exchanger 111 can simultaneously act on the air inlet channels, thereby realizing synchronous high-temperature preheating of air circulating in all the air inlet channels.

In addition, in the first embodiment, the gas water heater further includes a heater (not shown in the drawings) and a controller (not shown in the drawings), the controller is electrically connected to the heater, the controller is used for controlling the heater to heat the external air sucked by the air intake assembly 3, and controlling the heater to be turned off when the flue gas discharged from the burner 2 passes through the corresponding heat exchanger 11. Of course, it can also be configured that the controller is used to control the power of the heater to be reduced when the flue gas discharged from the burner 2 passes through the corresponding heat exchanger 11, so as to achieve the purpose of preheating the air at the high temperature by the heat exchanger 11 and the heater together. The heater can be an electric heating element such as an electric heating wire and an electric heating pipe, and can also be a preheating device which generates heat by using mixed combustion of gas and air. The electric heating element can be referred to a hair drier and other heating wind equipment. It should be noted that the number of the heaters may be one or more, and when the number of the heaters is plural, the multi-stage preheating of the outside air may be realized. The controller may be configured as a control chip or a control circuit according to the prior art, and will not be described in detail herein.

The working principle of the gas water heater of the present invention is explained in connection with the first embodiment of the gas water heater described above:

after the gas water heater is started, the air inlet assembly 3 sucks external air and conducts high-temperature preheating, the gas assembly 4 sprays gas, the gas and the high-temperature preheated air enter the high-temperature air combustion chamber 21 according to a preset proportion, high-temperature smoke is generated after the gas and the high-temperature preheated air are ignited, after the high-temperature smoke reaches a preset target temperature, entrainment effect is formed by matching with high-speed jet flow, part of smoke is made to strongly circulate in the high-temperature air combustion chamber 21, the sprayed gas and the air are fully diluted, lower oxygen concentration is formed, the combustion reaction speed is reduced, higher temperature of the high-temperature air combustion chamber 21 is maintained, the temperature is higher than the spontaneous combustion point of the fuel, and spontaneous combustion is achieved. After entering the heat exchange chamber 121 from the high-temperature air combustion chamber 21, the flue gas firstly passes through the first heat exchanger 111 to exchange heat with the external air flowing in the air intake assembly 3, and assists or replaces the original air high-temperature preheating mode of the air intake assembly 3, thereby being beneficial to the continuous and efficient implementation of MILD combustion in the high-temperature air combustion chamber 21; the flue gas continues to pass through the second heat exchanger 112, and exchanges heat with tap water circulating in the water pipe 6 arranged at the second heat exchanger 112.

Also in order to optimize the performance of the gas water heater, please refer to fig. 2, in the second embodiment of the present invention, the high temperature air combustion chamber 21 has a gas inlet and a flue gas outlet; the gas heater still is equipped with backward flow piece 5, backward flow piece 5 is located high temperature air combustion chamber 21, backward flow piece 5 is used for will passing through the flue gas of burning back flow direction exhanst gas outlet direction in the high temperature air combustion chamber 21 and leading back to the gas inlet direction of flow direction.

It can be understood that the air inlet component 3 performs high-temperature preheating of externally sucked air, and the fuel gas sprayed by the fuel gas component 4 generates flue gas after ignition to generate entrainment effect, so as to realize high-temperature air combustion; furthermore, the arrangement of the backflow piece 5 strengthens the entrainment effect and the heat preservation effect of the high-temperature flue gas; flue gas generated after combustion in the high-temperature air combustion chamber 21 flows to the heat exchanger 11 to heat tap water. Thus, a practical gas water heater with high temperature air combustion (MILD combustion) function is realized.

Specifically, in the second embodiment, the high temperature air combustion chamber 21 is formed with a jet flow channel 51 communicating with the gas inlet at the position of the backflow member 5, that is, the jet flow channel 51 is used for passing through the flue gas generated by combustion in the high temperature air combustion chamber 21, the jet flow channel 51 has an air inlet and an air outlet, and the air inlet of the jet flow channel 51 is disposed corresponding to the gas inlet of the high temperature air combustion chamber 21. The backflow piece 5 has a guide surface 52 located at the air outlet of the jet flow channel 51, and in the direction away from the air inlet, the guide surface 52 gradually extends towards the side wall direction of the high-temperature air combustion chamber 21 to guide the flue gas passing through the jet flow channel 51 to the direction of the gas inlet, so that a backflow area is formed between the chamber wall of the high-temperature air combustion chamber 21 at the corresponding position and the outer wall of the jet flow channel 51, the flow path length of the flue gas is prolonged, and the heat preservation of the flue gas is realized.

Under the action of the backflow piece 5, the backflow path of the flue gas is approximately annular to form a backflow ring, wherein the inclination degree of the guide surface 52 approximately influences the annular diameter of the backflow ring, and the specific shape and the arrangement number of the guide surface 52 can basically determine the orientation and the number of the backflow ring and can be specifically adjusted according to actual requirements.

Further, in the second embodiment, the air inlet of the jet flow passage 51 is provided at a spacing from the gas inlet of the high temperature air combustion chamber 21 to define a return flow passage at the spacing for the flue gas to reenter the jet flow passage 51, so that the number of times the flue gas is recirculated in the high temperature air combustion chamber 21 can be increased. The air outlet of the jet flow channel 51 is arranged corresponding to the smoke outlet of the high-temperature air combustion chamber 21, so that at least part of smoke can flow back for many times in the high-temperature air combustion chamber 21 and then flows out through the smoke outlet.

Furthermore, in the second embodiment, the jet flow channel 51 may also have a main body section 53 connecting its air inlet and air outlet; the main section 53 extends from the gas inlet of the high temperature air combustion chamber 21 to the flue gas outlet of the high temperature air combustion chamber 21. So arranged, the extending direction of the main body section 53 defines the circulation direction of the flue gas in the jet flow channel 51; the straight arrangement of the main body section 53 helps to reduce the flow path of the flue gas in the jet flow channel 51, thereby avoiding reducing or disturbing the flow velocity of the flue gas, which would affect the backflow effect of the flue gas.

Of course, there are various solutions for forming the return piece 5 with the jet channel 51, wherein for example, the return piece 5 itself may be provided in a cylindrical shape, in which case the return piece 5 has a housing, which may be provided in an integral manner or may be formed by joining a plurality of housing components separately. The backflow piece 5 is directly and fixedly installed on the chamber wall of the high-temperature air combustion chamber 21, or is erected on the chamber wall of the high-temperature air combustion chamber 21 through an additionally arranged installation support, so that the backflow piece is convenient to disassemble, assemble and replace, and the structural integrity of the combustor 2 is not influenced.

Or, the backflow pieces 5 may be arranged in a plate shape, and the backflow pieces 5 and the chamber wall of the high-temperature air combustion chamber 21 together enclose to form a jet flow channel 51, at this time, one backflow piece 5 may be arranged, and one backflow piece 5 is an arc-shaped plate; or the backflow part 5 may be provided in plural, and a plurality of the backflow parts 5 are sequentially split to form a partial side wall of the jet flow channel 51. The number and the weight of the backflow pieces 5 are reduced, so that the overall structure of the gas water heater is simplified, and the overall weight of the gas water heater is reduced.

Of course, there are many technical solutions for forming the above-mentioned guide surface 52, in other embodiments, the guide surface may be arranged in a direction away from the gas inlet, the outlet of the jet flow channel 51 is gradually bent and extended toward the side wall of the high temperature air combustion chamber 21, and at this time, the channel wall of the jet flow channel 51 near the outlet forms the guide surface 52 as a whole. The arrangement is such that the jet flow channel 51 is approximately J-shaped, thereby realizing that the smoke forms a backflow ring in the direction defined by the bending part of the jet flow channel 51.

In the second embodiment of the present invention, the outlet of the jet channel 51 is divergent in the direction away from the gas inlet, and the channel wall of the jet channel 51 corresponding to the divergent position forms the guide surface 52. So set up for all can form above-mentioned backward flow circle along fluidic channel 51's circumference, make the flue gas can carry out the backward flow along fluidic channel 51's circumference, help optimizing the backward flow effect of flue gas.

Then, in the second embodiment, the inlets of the jet flow passages 51 are arranged to be divergent in the direction close to the gas inlet. Due to the arrangement, the caliber of the air inlet of the jet flow channel 51 is favorably enlarged, so that most of the smoke flowing back to the air inlet of the jet flow channel 51 can reenter the jet flow channel 51 along the gradually-enlarged arrangement of the air inlet; moreover, the diverging arrangement helps to converge the flue gas entering through the inlet of the jet passage 51, and helps to increase to some extent the velocity of the flue gas passing within the jet passage 51.

The working principle of the gas water heater of the present invention is explained in connection with the second embodiment of the gas water heater described above:

after the gas water heater is started, the air inlet assembly 3 sucks external air and performs high-temperature preheating, the gas assembly 4 sprays gas, the gas and the high-temperature preheated air enter the high-temperature air combustion chamber 21 according to a preset proportion, high-temperature flue gas is generated after the gas and the high-temperature preheated air are ignited, and after the high-temperature flue gas reaches a preset target temperature, the high-temperature flue gas is matched with jet gas under the action of the backflow piece 5 to form a entrainment effect, so that part of the flue gas is intensively circulated in the high-temperature air combustion chamber 21, the sprayed gas and the air are fully diluted to form lower oxygen concentration, the combustion reaction speed is reduced, the higher temperature of the high-temperature air combustion chamber 21 is maintained, the temperature is higher than the spontaneous combustion; the backflow effect of the backflow piece 5 is beneficial to the circulation backflow of the flue gas in the high-temperature air combustion chamber 21, and the heat preservation effect is enhanced by prolonging the flowing path. After entering the heat exchange chamber 121 from the high temperature air combustion chamber 21, the flue gas passes through the heat exchanger 11 to exchange heat with the tap water flowing through the water pipe 6 arranged at the heat exchanger 11.

Also, referring to fig. 3, in order to optimize the performance of the gas water heater, in a third embodiment provided by the present invention, the gas water heater may be provided with two heat exchangers 11 in the first embodiment and the backflow element 5 in the second embodiment at the same time, and therefore, the third embodiment includes all the technical solutions of the first embodiment and the second embodiment described above, and details are not repeated here. Because the circulation route of backward flow spare 5 helps prolonging the flue gas in high temperature air combustion chamber 21 is long, realizes the abundant burning and the backward flow of gas and air, and reaches the heat preservation effect for the flue gas that flows from the exhanst gas outlet of high temperature air combustion chamber 21 carries more heat transfer heats, helps two heat exchanger 11's abundant heat transfer.

The working principle of the gas water heater of the present invention is explained in connection with the third embodiment of the gas water heater described above:

after the gas water heater is started, the air inlet assembly 3 sucks external air and performs high-temperature preheating, the gas assembly 4 sprays gas, the gas and the high-temperature preheated air enter the high-temperature air combustion chamber 21 according to a preset proportion, high-temperature flue gas is generated after the gas and the high-temperature preheated air are ignited, and after the high-temperature flue gas reaches a preset target temperature, the high-temperature flue gas is matched with jet gas under the action of the backflow piece 5 to form a entrainment effect, so that part of the flue gas is intensively circulated in the high-temperature air combustion chamber 21, the sprayed gas and the air are fully diluted to form lower oxygen concentration, the combustion reaction speed is reduced, the higher temperature of the high-temperature air combustion chamber 21 is maintained, the temperature is higher than the spontaneous combustion; the backflow effect of the backflow piece 5 is beneficial to the circulation backflow of the flue gas in the high-temperature air combustion chamber 21, and the heat preservation effect is enhanced by prolonging the flowing path. After entering the heat exchange chamber 121 from the high-temperature air combustion chamber 21, the flue gas firstly passes through the first heat exchanger 111 to exchange heat with the external air flowing in the air intake assembly 3, and assists or replaces the original air high-temperature preheating mode of the air intake assembly 3, thereby being beneficial to the continuous and efficient implementation of MILD combustion in the high-temperature air combustion chamber 21; the flue gas continues to pass through the second heat exchanger 112, and exchanges heat with tap water circulating in the water pipe 6 arranged at the second heat exchanger 112.

Next, in the first, second, and third embodiments described above, the gas module 4 has the injection port; the injection port passes through the heat exchange chamber 121 and the first heat exchanger 111 in this order, and is disposed in the high temperature air combustion chamber 21. It can be understood that the MILD burner 2 has a small volume, is convenient to be applied to small-volume gas water heaters and other equipment, and has a wider application prospect. Therefore, the injection port of the gas assembly 4 directly passes through the heat exchange chamber 121 and the first heat exchanger 111 and then extends into the high-temperature air combustion chamber 21, so that mutual interference between gas and flue gas circulating in the heat exchange chamber 121 can be avoided, and the structure of the gas water heater is compact. After installation, the jet orifice of the gas component 4 faces the vertical lower part in the high-temperature air combustion chamber 21, so that when the gas is jetted, entrainment effect is formed on two sides of the jetted airflow, and part of high-temperature flue gas circulates in the high-temperature air combustion chamber 21 and dilutes and ignites air jet flow so as to maintain the combustion of the high-temperature air.

Further, in the above embodiment, the injection port of the gas combustion assembly 4 is provided through the middle of the first heat exchanger 111. The jet orifice of the gas component 4 is arranged in the middle, so that the space sizes of the two sides of the jetted gas jet flow are symmetrical, the entrainment air flow formed on the two sides of the jetted gas jet flow is more balanced, and the air and the gas in the whole high-temperature air combustion chamber 21 are fully diluted and mixed. It should be noted that the injection port of the gas module 4 is arranged at the top of the high temperature air combustion chamber 21 as much as possible, so as to ensure the injection distance of the gas and improve the entrainment effect.

Based on the above, when the air intake assembly 3 has a plurality of air outlets, that is, a plurality of air intake channels are formed, the plurality of air intake channels may share one air outlet, or the plurality of air intake channels may be respectively configured with one air outlet. Wherein, when air inlet subassembly 3 possesses two at least air outlets, two at least air outlets set up corresponding to the circumference interval of the jet orifice of gas subassembly 4. For example, when the air intake assembly 3 is provided with two air outlets, the two air outlets are arranged at intervals corresponding to two lateral sides of the injection port of the gas combustion assembly 4. The plurality of air outlets are arranged at intervals along the circumferential direction of the jet orifice, can be arranged in a central symmetry mode about the central line of the jet orifice, in an axial symmetry mode about the radius line of the jet orifice, in an equidistant mode or in a random dispersion mode, and can be specifically adjusted according to actual requirements. So set up, high temperature preheats the air and gets into in the high temperature air combustion chamber 21 from the circumference of gas respectively for the burning is more abundant, and the flue gas of production is more complete, and balanced entrainment effect, and be of value to gas and air and obtain abundant dilution and mix, maintain the high temperature air burning.

Next, in the above embodiment, the flue gas passage 13 communicating with the high temperature air combustion chamber 21 is formed between the outer wall of the burner 2 and the chamber wall of the heat exchange chamber 121, and the communication port of the flue gas passage 13 and the high temperature air combustion chamber 21 is provided away from the two heat exchangers 11. The flue gas channel 13 defines accurate flowing direction for the circulation of flue gas, and the communication ports of the flue gas channel 13 and the high-temperature air combustion chamber 21 are arranged far away from the two heat exchangers 11, so that the extension of the circulation path of the flue gas is facilitated, and the rapid discharge of the flue gas generated in the high-temperature air combustion chamber 21 is avoided to cause sudden temperature change; in addition, the arrangement of the flue gas channel 13 is equivalent to a heat insulation structure wrapped on the periphery of the combustor 2, which is helpful for maintaining the temperature of the high-temperature air combustion chamber 21 in the combustor 2, avoiding the heat loss of the combustor 2, and ensuring that the flue gas in the high-temperature air combustion chamber 21 is at a target temperature or above the target temperature, i.e. higher than the spontaneous combustion point of the fuel, thereby ensuring sufficient spontaneous combustion.

Specifically, when the burner 2 is disposed vertically below the heat exchanger 11, the communication between the burner 2 and the heat exchange chamber 121, i.e., the flue gas outlet, is disposed at the bottom of the burner 2, so as to further extend the distance from the heat exchanger 11 and optimize the heat preservation effect.

Further, the housing assembly 12 is provided with an exhaust port 14 communicating with the heat exchange chamber 121, the exhaust port 14 being provided on a side of the second heat exchanger 112 facing away from the burner 2. The flue gas generated by combustion in the high-temperature air combustion chamber 21 passes through the heat exchangers 11 or sequentially passes through the two heat exchangers 11, and then is used for high-temperature preheating for external air and good heat exchange for tap water. The smoke outlet 14 is arranged on one side of the second heat exchanger 112, which is back to the burner 2, so that the smoke can be discharged from the smoke outlet 14 after the smoke exchanges heat with the heat exchanger 11 sufficiently, which is beneficial to the full utilization of the smoke.

In addition, gas heater still includes the valve body (the attached drawing does not mark), and gas subassembly 4 is located to the valve body, and the valve body is used for opening after air inlet assembly 3 will heat to the outside air of predetermineeing the target temperature for high temperature air combustion chamber 21 to supply the gas to get into high temperature air combustion chamber 21. The valve body can be directly opened or closed through manual operation of a user, and also can be electrically connected with the controller and opened or closed under the control of the controller. The high-temperature preheated external air firstly enters the high-temperature air combustion chamber 21 to provide sufficient air and temperature for the gas to enter and ignite. The gas and air are ignited to generate smoke, and a entrainment effect is formed through high-speed jet flow, so that part of the smoke circularly flows back in the high-temperature air combustion chamber 21, then the injected gas and air are fully diluted to form lower oxygen concentration, the combustion reaction speed is reduced, the higher temperature of the high-temperature air combustion chamber 21 is maintained, the temperature is higher than the self-ignition point of the fuel, and the self-ignition is realized.

Claims

1. A combustion heat exchange assembly, comprising:

2. The combustion heat exchange assembly of claim 1, wherein the two heat exchangers include a first heat exchanger through which outside air passes, and a second heat exchanger;

the first heat exchanger is arranged on one side of the combustor, and the second heat exchanger is arranged on one side of the first heat exchanger, which is back to the combustor.

3. The combustion heat exchange assembly of claim 2 wherein the burner is disposed vertically below the two heat exchangers.

4. The combustion heat exchange assembly of claim 2, wherein a flue gas channel communicated with the high temperature air combustion chamber is formed between the outer wall of the combustor and the chamber wall of the heat exchange chamber, and the communication port of the flue gas channel and the high temperature air combustion chamber is arranged far away from the two heat exchangers.

5. A combustion heat exchange assembly according to claim 2, wherein the housing assembly is provided with an exhaust port communicating with the heat exchange chamber, the exhaust port being provided on a side of the second heat exchanger facing away from the burner.

6. A gas water heater, comprising:

the combustion heat exchange assembly of any one of claims 1 to 5;

7. The gas water heater of claim 6, wherein said air intake assembly is adapted to draw in outside air and to deliver it to said high temperature air combustion chamber after being heated to a predetermined target temperature by said first heat exchanger.

8. The gas fired water heater of claim 7, wherein said intake assembly is provided with a plurality of supply air ports, wherein:

9. The gas water heater of claim 8, wherein said gas assembly has an injection port;

10. The gas water heater of claim 9, wherein the injection port of the gas assembly is disposed through a middle portion of the first heat exchanger.

11. The gas water heater of claim 10, wherein the air intake assembly is provided with at least two air outlets, and the at least two air outlets are circumferentially spaced relative to the injection port of the gas assembly.

12. The gas water heater of claim 6, further comprising a heater and a controller, wherein the controller is electrically connected to the heater, and the controller is configured to control the heater to heat the external air sucked by the air intake assembly and to control the heater to be turned off when the flue gas discharged from the burner passes through the corresponding heat exchanger.

13. The gas water heater of claim 6, further comprising a valve body disposed on the gas assembly, the valve body being configured to open after the air intake assembly delivers outside air heated to a predetermined target temperature to the high temperature air combustion chamber, so that gas can enter the high temperature air combustion chamber.