CN111520713A

CN111520713A - Closed full premix combustion system and water heater

Info

Publication number: CN111520713A
Application number: CN202010434877.7A
Authority: CN
Inventors: 艾穗江; 王子康; 胡定刚; 刘兵
Original assignee: Guangdong Macro Gas Appliance Co Ltd
Current assignee: Guangdong Macro Gas Appliance Co Ltd
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2020-08-11

Abstract

The invention discloses a closed full premix combustion system, comprising: the combustion chamber comprises a closed cavity, an exhaust port is arranged at one end of the combustion chamber, an air inlet is arranged at the other end of the combustion chamber, and the air inlet and the exhaust port are both communicated with the accommodating cavity; the injection pipe and the gas inlet pipe are arranged in the shell; the fan is installed on one side close to the exhaust port, and the fan is communicated with the cavity. The combustion chamber of the invention adopts a fully closed structure, simultaneously, a fully premixed mode of injecting air by gas is adopted, the suction force of a fan can be fully acted on the flame hole of the combustor under the closed condition, at the moment, the air injection amount of the injection pipe is jointly controlled by the gas pressure and the fan rotating speed, the combustion heat intensity and the combustion load are improved by the suction force of the fan, the control of combustion segmentation is realized on the basis of fully premixed combustion, and the combustion system has reliable performance, high efficiency and environmental protection.

Description

Closed full premix combustion system and water heater

Technical Field

The invention relates to a gas water heater, in particular to a fully premixed gas water heater.

Background

The combustion premixing modes of the gas water heater are mainly divided into two modes, namely partial premixing and full premixing. At present, most of domestic gas water heater products adopt atmospheric combustion, namely a partial premixing mode, the structural design and the control method of the combustion mode are simpler, but due to the limitation of the premixing mode, gas flame can not be completely combusted, so that the smoke is generally poorer, and particularly the content of nitrogen oxides is higher. The full-premixing combustion technology belongs to the advanced combustion technology, the combustion efficiency is high, and simultaneously the contents of carbon monoxide, nitric oxide and the like in the flue gas are extremely low. Although the prior art already has a fully premixed gas water heater, most of the prior fully premixed technical schemes adopt an injection mode of injecting gas by air, a strong-drum direct current fan and an air-fuel proportional valve are used for proportioning air and gas, and a ceramic plate or a metal fiber net is mostly adopted by a burner. The scheme has high manufacturing cost and large volume of the whole machine, and can not carry out combustion sectional control.

Disclosure of Invention

The present invention is directed to a fully premixed water heater that solves one or more of the problems of the prior art and provides at least one of the advantages of the present invention.

The solution of the invention for solving the technical problem is as follows: a closed fully premixed combustion system comprising:

the combustion chamber comprises a closed cavity, an exhaust port is arranged at one end of the combustion chamber, an air inlet is arranged at the other end of the combustion chamber, and the air inlet and the exhaust port are both communicated with the accommodating cavity;

one end of the injection pipe is communicated with the air inlet;

the fuel gas inlet pipe is provided with a nozzle, and the nozzle is communicated with the other end of the injection pipe; a gap is arranged between the nozzle and the injection pipe and is communicated with the outside air;

the fan is installed on one side close to the exhaust port, and the fan is communicated with the cavity.

The invention has the beneficial effects that: the combustion chamber of the invention adopts a fully closed structure, the ejector pipe becomes the only entry way for mixing air and combustion, meanwhile, a fully premixed mode of injecting air by gas is applied, the suction force of a fan can be fully acted on a flame hole of the combustor under the closed condition, the air injection amount of the ejector pipe is controlled by the gas pressure and the rotating speed of the fan together, and the gas pressure is generally fixed during working, so that the air and the gas can be mixed according to a certain set proportion by matching the rotating speed of the fan with the working load, the combustion heat intensity and the combustion load are improved by the suction force of the fan, and the combustion system realizes the control of combustion segmentation on the basis of fully premixed combustion, has reliable performance, is efficient and is environment-friendly.

As a further improvement of the technical scheme, the injection pipes are provided with a plurality of nozzles, the nozzles correspond to the injection pipes one by one, and the gas inlet pipe is provided with an electromagnetic valve. The on-off of the gas inlet pipe can be controlled through an electromagnetic field. The adjustment of the air supply amount is realized.

As a further improvement of the technical scheme, a fuel gas proportional valve is further arranged in the fuel gas inlet pipe. By adding the gas proportional valve, the pressure of the gas can be adjusted.

As a further improvement of the technical scheme, the combustion chamber comprises an inner wall, and a heat insulation layer is arranged on the inner wall. The heat loss of combustion can be reduced by adding the heat insulation layer in the combustion chamber.

As a further improvement of the technical scheme, the heat exchanger further comprises a heat exchange device, and the heat exchange device is arranged between the cavity and the exhaust port.

As a further improvement of the technical scheme, the exhaust fume collecting device further comprises an exhaust fume collecting hood, wherein the exhaust fume collecting hood is fixedly connected with the combustion chamber and comprises a fume inlet and a fume outlet, the fume inlet is communicated with the exhaust port, and the fan is arranged between the fume inlet and the fume outlet. Besides providing air and fuel gas for the combustion chamber, the draft of the fan also discharges the burnt exhaust gas.

As a further improvement of the technical scheme, the burner flame hole cooling device further comprises a burner flame hole and a cooling pipeline, and the burner flame hole is connected with the cooling pipeline. The cooling pipeline is added on the flame hole of the burner, and the cooling pipeline is utilized to cool the flame hole of the burner, so that the combustion efficiency can be further improved.

As a further improvement of the technical scheme, the water cooling device further comprises a water inlet pipe and a water outlet pipe, wherein the water inlet pipe is communicated with the cooling pipeline, a water valve is arranged in the water inlet pipe, and a temperature sensor is arranged in the water outlet pipe.

Meanwhile, the invention also provides a water heater using the closed fully premixed combustion system.

Drawings

In order to more clearly illustrate the technical solution in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is clear that the described figures are only some embodiments of the invention, not all embodiments, and that a person skilled in the art can also derive other designs and figures from them without inventive effort.

FIG. 1 is a schematic diagram of the system architecture of the present invention.

Detailed Description

The conception, the specific structure, and the technical effects produced by the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings to fully understand the objects, the features, and the effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention. The drawings illustrate a preferred embodiment of the invention and, together with the description, serve to complement the description with figures so that the person may visually and vividly understand each and every feature and every technical solution of the invention, but are not to be construed as limiting the scope of the invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions. Meanwhile, all technical characteristics in the invention can be interactively combined on the premise of not conflicting with each other.

Referring to fig. 1, the water heater comprises a housing, wherein a sealed fully premixed combustion system and a smoke collecting hood 700 are arranged in the housing, a gas inlet, a water inlet pipe 10 and a water outlet pipe 20 are arranged outside the housing, a water valve 30 is arranged in the water inlet pipe 10, and a temperature sensor is arranged in the water outlet pipe 20.

The closed fully premixed combustion system comprises: the combustion chamber 100 comprises a closed cavity 110, the upper end of the combustion chamber 100 is provided with an exhaust port 120, and the lower end of the combustion chamber 100 is provided with an air inlet 130; the injection pipe 200 is of a venturi structure, the injection pipe 200 comprises a contraction section, a throat and a diffusion section, the diffusion section is communicated with the air inlet 130, the contraction section is communicated with the gas inlet pipe 300, specifically, the gas inlet pipe 300 is provided with a nozzle 310, the nozzle 310 faces the contraction section, a gap is arranged between the nozzle 310 and the contraction section of the injection pipe 200, and the gap is communicated with the outside air; the fan 400 is installed at a side close to the exhaust port 120, and the fan 400 communicates with the cavity 110.

The smoke collecting cover 700 is fixedly connected with the combustion chamber 100, the smoke collecting cover 700 comprises a smoke inlet 710 and a smoke outlet 720, the smoke inlet 710 is communicated with the exhaust port 120, and the fan 400 is arranged between the smoke inlet 710 and the smoke outlet 720.

The combustion chamber 100 is further provided with a burner and a heat exchanger 600 (i.e., a heat exchange device), the heat exchanger comprises a water inlet end and a water outlet end, the water inlet end is connected with the water inlet pipe 10, and the water outlet end is connected with the water outlet pipe 20.

When the water heater works, the water heater is started, the water valve 30 in the water inlet pipe 10 is started, cold water enters the water heater from the water inlet pipe 10, gas enters the water heater from a gas inlet, the gas is sprayed into the injection pipe 200 through the nozzle 310 of the gas inlet pipe 300, then air is simultaneously brought into the injection pipe 200 under the action of the injection pipe 200, and the gas and the air are fully premixed in the injection pipe 200. The mixed gas enters the burner, is ignited after passing through the flame holes of the burner, the high-temperature gas after combustion exchanges heat with cold water after passing through the heat exchanger, the cold water is heated after the heat exchange, and then is discharged from the water outlet pipe 20, the high-temperature gas is cooled after the heat exchange, and is discharged under the action of the fan 400. Meanwhile, because the combustion chamber 100 is a relatively closed space in the water heater, the injection pipe 200 of the burner becomes the only way for mixing air and combustion during combustion. Under the condition of a closed type, the drawing force of the fan 400 can be completely acted on the flame hole of the combustor, at the moment, the air injection amount of the injection pipe is jointly controlled by the gas pressure of the nozzle 310 and the rotating speed of the fan 400, the valve opening of the gas proportional valve is only related to the working load, the opening of the proportional valve is unchanged under the same working load, the gas pressure and the gas flow are fixed values, and therefore the rotating speed of the fan 400 can be matched with the working load, so that the air and the gas are mixed according to a certain set proportion, and the condition of complete premixed combustion is met.

Further as a preferred embodiment, there are a plurality of the injection pipes 200, the nozzles 310 correspond to the injection pipes 200 one to one, and the gas inlet pipe 300 is provided with an electromagnetic valve 320. A gas proportional valve 330 is further disposed in the gas inlet pipe 300.

Further as a preferred embodiment, the combustion chamber 100 comprises an inner wall, and the inner wall is provided with a heat insulation layer 500. Preferably, the heat insulation layer 500 is heat insulation asbestos.

Further as a preferred embodiment, the combustion chamber 100 is further provided with a sealing structure, and the sealing structure further improves the sealing reliability of the cavity 110 of the combustor 100. Further reducing the loss of suction from the fan 400.

Further as a preferred embodiment, the burner flame hole device further comprises a burner flame hole 800 and a cooling pipe 900, wherein the burner flame hole 800 is connected with the cooling pipe 900.

Cold water passes through the water valve and before entering the heat exchanger, it will first pass through the internal cooling pipe 900 located below the burner fire hole in order to cool the fire hole. Because the flame temperature of the full premix combustion is higher, and the flame height is lower, the high temperature of the flame holes of the burner easily causes the tempering phenomenon of the gas flame. Therefore, in the working state, tap water is utilized to cool the flame holes after passing through the cooling pipeline 900, and the temperature of the flame holes of the burner and the temperature of the flow channel below the flame holes of the burner are reduced, so that the tempering phenomenon is prevented, and the combustion stability and the combustion efficiency are improved. Meanwhile, the cooling pipeline 900 can heat tap water to a certain degree, absorbs heat dissipation of a part of the combustor, and improves heat exchange efficiency.

The gas proportional valve 330 adjusts the valve opening according to the load, and delivers a certain flow rate of gas to the gas distribution pipe. At this time, if the workload is small, that is, the temperature rise of the inlet and outlet water is lower than a certain set value, the main controller can only make a small part of the burners work by closing one of the electromagnetic valves 320, and similarly, when the temperature rises to the set value, the electromagnetic valves are opened, and all the burners start to work, so that the effect of staged combustion is achieved, and the adjustment range of the water temperature is expanded.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that the present invention is not limited to the details of the embodiments shown and described, but is capable of numerous equivalents and substitutions without departing from the spirit of the invention as set forth in the claims appended hereto.

Claims

1. A closed full premix combustion system is characterized in that: the method comprises the following steps:

the combustion chamber (100) comprises a closed cavity (110), one end of the combustion chamber (100) is provided with an exhaust port (120), the other end of the combustion chamber (100) is provided with an air inlet (130), and the air inlet (130) and the exhaust port (120) are both communicated with the cavity (110);

the ejector pipe (200), one end of the ejector pipe (200) is communicated with the air inlet (130);

the fuel gas inlet pipe (300) is provided with a nozzle (310), and the nozzle (310) is communicated with the other end of the injection pipe (200); a gap is arranged between the nozzle (310) and the injection pipe (200), and the gap is communicated with the external air;

a fan (400), the fan (400) being installed at a side close to the exhaust port (120), and the fan (400) being communicated with the cavity (110).

2. The closed fully premixed combustion system as set forth in claim 1, wherein: the injection pipes (200) are provided with a plurality of nozzles (310), the nozzles correspond to the injection pipes (200) one by one, and the gas inlet pipe (300) is provided with electromagnetic valves (320).

3. The closed fully premixed combustion system as set forth in claim 2, wherein: and a gas proportional valve (330) is also arranged in the gas inlet pipe (300).

4. The closed fully premixed combustion system as set forth in claim 1, wherein: the combustion chamber (100) comprises an inner wall, and a heat insulation layer (500) is arranged on the inner wall.

5. The closed fully premixed combustion system as set forth in claim 1, wherein: the heat exchanger is characterized by further comprising a heat exchange device (600), wherein the heat exchange device (600) is arranged between the cavity (110) and the exhaust port (120).

6. The closed fully premixed combustion system as set forth in claim 1, wherein: still include collection petticoat pipe (700), collection petticoat pipe (700) with combustion chamber (100) fixed connection, collection petticoat pipe (700) are including advancing smoke inlet (710) and exhaust port (720), advance smoke inlet (710) with gas vent (120) intercommunication, fan (400) are located advance between smoke inlet (710) and the exhaust port (720).

7. The closed fully premixed combustion system as set forth in claim 1, wherein: the burner flame hole (800) is connected with the cooling pipeline (900).

8. The closed fully premixed combustion system as set forth in claim 7, wherein: still include inlet tube (10) and outlet pipe (20), inlet tube (10) with cooling tube (900) intercommunication, be equipped with water valve (30) in inlet tube (10), be equipped with temperature sensor (40) in outlet pipe (20).

9. A water heater characterized by comprising the closed fully premixed combustion system as claimed in any one of claims 1 to 8.