Correcting device for cold start air-fuel ratio of premixing burner

Abstract

The utility model discloses a device for correcting the cold start air-fuel ratio of a premixing combustor, which comprises a combustion chamber, a combustor is arranged in the combustion chamber, and a flue gas pipeline is arranged on the combustion chamber and used for outputting flue gas in the combustion chamber; an air supply device is further included, the output end of the air supply device is provided with an airflow pipeline communicated with the combustor, and the air supply device conveys airflow to the combustor through the airflow pipeline. A heat exchanger is included. The airflow pipeline and the flue gas pipeline are respectively connected with a cold pipe and a heat pipe of the heat exchanger, and heat exchange is carried out between the flue gas pipeline and the airflow pipeline; comprising a temperature sensor, the temperature sensor is arranged on an airflow pipeline, and the temperature sensor is used for collecting the temperature of airflow flowing to a combustor on the airflow pipeline; a throttling valve is arranged on the air flow pipeline and used for adjusting the ventilation capacity of the air flow pipeline according to the air flow temperature so as to expect to improve the problem of how to correct the air-fuel ratio due to different air-fuel ratio requirements under the two working conditions of starting and running when heat energy in the combustion chamber is used for preheating air.

Description

Technical Field

[0001] The utility model relates to combustion device control, in particular to a correction device for the air-fuel ratio of a premix burner during cold start. Background Art

[0002] At present, the use of premixed gas in burners is an environmentally friendly way to improve the efficiency and effect of combustion. The principle is that after the fuel gas and air are fully mixed in the burner, a uniform mixture can be formed, which enables the mixture to burn more quickly and evenly when ignited. At the same time, premixing can ensure that the gas is evenly distributed during the combustion process, so that the combustion is more complete. The uniform mixed gas is conducive to the full combustion reaction and reduces the phenomenon of incomplete combustion. On the one hand, it reduces the residual and waste of fuel, and on the other hand, it reduces the harmful gases generated during the combustion process, such as carbon monoxide and nitrogen oxides.

[0003] In traditional hot air burners, the air required for combustion is preheated through a heating tube, which makes combustion easier to start and maintain. Through a fixed air-fuel ratio, it can ensure that limited oxygen can be more effectively mixed with the fuel and complete combustion, thereby achieving the purpose of improving thermal efficiency and reducing fuel consumption. However, preheating directly through a heating tube obviously requires higher energy consumption for the equipment.

[0004] As the research deepened, for the purpose of energy conservation and emission reduction, the heat energy in the combustion chamber was used to preheat the air. After testing, it was found that this method can obviously eliminate the energy consumption of the heating tube during continuous use. However, during the startup of the equipment, the combustion chamber temporarily does not have enough heat energy to utilize, so the input airflow is cold air. Since the density of cold air is greater than that of hot air and the oxygen content is relatively high, if the air-fuel ratio of the equipment is not adjusted, the combustion during the startup process is prone to inadequate combustion and pollutants are easily generated. On this basis, it is worth studying how to make the hot air burner perform air-fuel ratio correction during the cold start process and stable operation. Utility Model Content

[0005] The utility model aims to provide a device for correcting the air-fuel ratio of a premix burner during cold start, in order to improve the problem of how to correct the air-fuel ratio when the air is preheated by the heat energy in the combustion chamber and the air-fuel ratio requirements are different under the two working conditions of starting and running.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A correction device for the air-fuel ratio of a premix burner during cold start, comprising a combustion chamber, wherein a burner is arranged in the combustion chamber, and a flue gas duct is arranged on the combustion chamber, and the flue gas duct is used to output the flue gas in the combustion chamber; further comprising an air supply device, wherein an air flow pipeline connected to the burner is arranged at the output end of the air supply device, and the air supply device delivers air flow to the burner through the air flow pipeline; further comprising a heat exchanger; the air flow pipeline and the flue gas duct are respectively connected to a cold pipe and a hot pipe of the heat exchanger, and the heat exchanger enables heat exchange between the flue gas duct and the air flow pipeline; further comprising a temperature sensor, the temperature sensor is arranged on the air flow pipeline, and the temperature sensor is used to collect the temperature of the air flow flowing to the burner on the air flow pipeline; the air flow pipeline is provided with a throttle valve, and the throttle valve is used to adjust the ventilation volume of the air flow pipeline according to the air flow temperature. The idea is: by setting up a heat exchanger, the waste heat in the flue gas generated after combustion is used to preheat the airflow input to the burner, so as to reduce the use of external energy and save energy consumption. The temperature of the airflow is monitored in real time by a temperature sensor. The device adjusts the gas supply according to the actual temperature change, and uses the throttle valve to adjust the output of the airflow to realize dynamic correction of the air-fuel ratio.

[0008] Preferably, a regulating valve is provided at the input end of the air supply device, and the regulating valve is used to adjust the output of the airflow.

[0009] A further technical solution is that the temperature sensor is signal-connected to the throttle control unit, and the temperature sensor sends a temperature signal to the throttle control unit, which controls the opening and closing degree of the throttle valve.

[0010] A further technical solution is that the air flow pipeline includes a combustion-supporting pipeline and an air supply pipeline, the combustion-supporting pipeline is connected to the output end of the heat exchanger cold pipe, and the air supply pipeline is connected to the input end of the heat exchanger cold pipe.

[0011] Preferably, a bypass pipeline is arranged on the above-mentioned airflow pipeline, and the bypass pipeline is located between the throttle valve and the air supply device, and a solenoid valve is arranged on the above-mentioned bypass pipeline; when the air supply device outputs airflow at a constant rate, the above-mentioned solenoid valve is used to cooperate with the bypass pipeline to maintain the airflow pressure in the airflow pipeline within a set range.

[0012] Preferably, a first pipe as a cold pipe and a second pipe as a hot pipe are provided in the inner cavity of the heat exchanger, and the first pipe exchanges heat with the second pipe; the air flow pipeline is connected to the first pipe, and the flue gas pipeline is connected to the second pipe.

[0013] A further technical solution is that the first pipe and the second pipe are distributed in a serpentine shape, and the side wall of the first pipe and the side wall of the second pipe are close to each other; wherein the area where the first pipe and the second pipe are close to each other is made of heat-conducting material and serves as a heat-conducting surface.

[0014] A further technical solution is that a heat exchange plate is provided between the first pipe and the second pipe, both sides of the heat exchange plate are attached to heat conductive surfaces, and the heat exchange plate transfers heat between the first pipe and the second pipe.

[0015] A further technical solution is that heat-conducting needles are provided outside the heat exchange plate, and the heat-conducting needles extend to the inner cavity of the first pipe and the inner cavity of the second pipe respectively.

[0016] Compared with the prior art, the beneficial effects of the utility model are at least one of the following:

[0017] The utility model outputs air flow to the burner through an air supply device. When the burner is in a cold start state, the air flow is cold air with a large density. The air flow pressure output by the heat exchanger to the air flow pipeline is relatively small, and the oxygen content of the air flow at a constant flow rate is greater than that of hot air. At this time, the air-fuel ratio of the burner is corrected by reducing the air flow rate to meet the cold start requirement.

[0018] At the same time, when the burner is in working condition, the heat exchanger is used to heat the airflow, which increases the pressure of the airflow output by the heat exchanger to the airflow pipeline. The oxygen content of the same airflow in the airflow pipeline will decrease. At this time, the airflow needs to be increased so that the air-fuel ratio of the burner can be corrected, thereby ensuring that the burner maintains the best air-fuel ratio under different working conditions and optimizes the combustion effect.

[0019] The utility model can relatively conveniently adjust the air flow rate by adaptively adjusting the ventilation volume of the air flow pipeline through the throttle valve, and collect temperature signals through the temperature sensor, so as to judge the oxygen content of the air flow pipeline by the air flow temperature; so that the throttle valve can timely adjust the air flow rate of the air flow pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the utility model.

[0021] Figure 2 This is a schematic diagram of the airflow direction of the utility model.

[0022] Figure 3 This is a schematic diagram of a heat exchanger according to an embodiment of the present invention.

[0023] Figure 4 The figure is a working schematic diagram of a heat exchange plate according to an embodiment of the utility model.

[0024] Explanation of the reference numerals: 1-combustion chamber, 2-air supply device, 3-air flow pipeline, 4-heat exchanger, 5-temperature sensor, 6-throttle valve, 101-burner, 102-flue gas duct, 301-combustion-supporting pipeline, 302-air supply pipeline, 401-first pipeline, 402-second pipeline, 403-heat exchange plate, 404-heat conduction needle. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0026] At present, premixed gas is also conducive to environmentally friendly combustion of the burner. By presetting a reasonable air-fuel ratio, the combustion efficiency of the burner can be maximized, and the combustion process can also be controlled. The current premixing effect has become one of the important means to improve combustion. The air-fuel ratio of the premixed gas also directly contributes to improving the stability of equipment operation. The air-fuel ratio determines the ratio of fuel and air. A reasonable air-fuel ratio can make the flame more stable during the combustion process and reduce the risk of flame jumping and extinguishing caused by incomplete or uneven combustion.

[0027] At present, the burners on the market usually give a reasonable air-fuel ratio range to guide users. At the same time, users can choose according to the characteristics of the gas and actual needs. However, when the burner is premixed, the air-fuel ratio may give different air-fuel ratio ranges due to different starting conditions. Generally, there will be a difference between the air-fuel ratio during cold air start and the air-fuel ratio during hot air premixing. During cold air start, due to the low temperature and high air density, the same volume of air contains more oxygen molecules. During hot air premixing, the gas temperature increases, the air density decreases, and the oxygen content of the same volume of air decreases. Under low temperature conditions, the volatility of the fuel is poor, and after the gas is preheated, the fuel is easy to evaporate and atomize. Obviously, it is not ideal to use a constant air-fuel ratio in this case. The air-fuel ratio of the burner needs to be corrected according to the working conditions.

[0028] Embodiment 1:

[0029] refer to Figure 1 and Figure 2 As shown, one embodiment of the utility model is a correction device for the cold start air-fuel ratio of a premixed burner, comprising a combustion chamber 1, which is an existing combustion chamber, and a burner 101 is arranged in the combustion chamber 1. A flue gas duct 102 is arranged on the combustion chamber 1, and the flue gas duct 102 is used to output the flue gas in the combustion chamber 1, and the flue gas duct 102 is mainly used to discharge the high-temperature flue gas in the combustion chamber 1.

[0030] Exemplarily, the burner 101 is an existing hot air type burner, and the burner 101 mixes fuel and air and burns them, and the combustion port of the burner 101 for combustion is located in the combustion chamber 1.

[0031] For reference, the outer wall of the flue gas duct 102 is insulated so that when the flue gas duct 102 discharges the flue gas in the combustion chamber 1, its temperature will not dissipate.

[0032] It is worth noting that, since the current combustion cannot achieve complete combustion and smoke is also generated during the consumption of fuel, smoke still exists when the burner 101 performs combustion in the combustion chamber 1.

[0033] The correction device also includes an air supply device 2, which can be an existing fan, turbofan, or other oxygen-containing gas output device. The output end of the air supply device 2 is provided with an airflow pipeline 3 connected to the burner 101, and the air supply device 2 delivers airflow to the burner 101 through the airflow pipeline 3. The air supply device 2 delivers the airflow to the burner 101 through the airflow pipeline 3, so that the burner 101 obtains the oxygen required for premixed combustion.

[0034] The heat exchanger 4 is one of the core components of the correction device. The heat exchanger 4 can be an existing product. The heat exchanger 4 is used to exchange heat between the heat of the flue gas duct 102 and the cold gas sent by the air supply device 2, so that the high-temperature flue gas can preheat the cold airflow entering the burner by heat exchange. The above-mentioned airflow pipeline 3 and the flue gas duct 102 are respectively connected to the cold pipe and the hot pipe of the heat exchanger 4, and the heat exchanger 4 enables heat exchange between the flue gas duct 102 and the airflow pipeline 3. The flue gas is drained by the hot pipe connected to the flue gas duct 102, and the cold gas is drained by the cold pipe connected to the airflow pipeline 3. Through the heat exchange between the cold pipe and the hot pipe of the heat exchanger 4, the heat of the flue gas can be transferred to the cold airflow, thereby increasing the airflow temperature in the airflow pipeline 3.

[0035] The cold air flow refers to the normal temperature air flow output by the air supply device 2 to the burner 101 ; the high temperature flue gas refers to the flue gas with a relatively high temperature output by the combustion chamber 1 .

[0036] Stable data collection is required on the airflow pipeline 3, so a temperature sensor 5 is set on the airflow pipeline 3, and the temperature sensor 5 can be an existing product. The temperature sensor 5 is set on the airflow pipeline 3, and the collection end of the temperature sensor 5 extends into the inner cavity of the airflow pipeline 3, and collects the temperature information of the inner cavity of the airflow pipeline 3 in real time. When there is gas flow in the airflow pipeline 3, the above-mentioned temperature sensor 5 is used to collect the temperature of the airflow flowing to the burner 101 on the airflow pipeline 3; the data collected by the temperature sensor 5 can help the system determine the current temperature condition of the airflow, and provide real-time data support for the adjustment of the airflow volume of the airflow pipeline 3.

[0037] The air flow pipeline 3 is provided with a throttle valve 6, wherein the throttle valve 6 may be an existing product, and the throttle valve 6 is used to adjust the ventilation volume of the air flow pipeline 3 according to the air flow temperature. The throttle valve 6 can adjust the ventilation volume of the air flow pipeline 3 according to the air flow temperature, thereby controlling the air flow entering the combustion chamber, so that the burner 101 can achieve a corresponding air-fuel ratio.

[0038] For reference, the throttle valve 6 controls the speed and flow rate of the fluid passing through the throttle valve by changing the position or opening of the throttle. When the opening of the throttle increases, the cross-sectional area of ​​the airflow through the throttle valve 6 increases, and the flow rate and flow rate also increase accordingly; when the opening of the throttle decreases, the cross-sectional area of ​​the fluid flowing through the throttle valve decreases, and the flow rate and flow rate also decrease accordingly. By continuously adjusting the position of the throttle, precise control of the fluid can be achieved. The throttle valve 6 adjusts the air flow according to the information provided by the temperature sensor 8, affecting the air-fuel ratio, helping to ensure that the temperature of the mixed gas during the combustion process is moderate, ensuring the stability of the combustion of the burner 101, and realizing automatic adjustment of the air-fuel ratio according to the actual temperature of the airflow.

[0039] Exemplarily, the operating condition under cold start conditions is: the heat exchanger 4 cannot heat the air flow pipeline 3, and the temperature sensor 5 detects that the air flow temperature is normal temperature. Under normal temperature conditions, the oxygen content of the air flow is relatively large, and the throttle valve 6 is coordinated to reduce the opening, thereby reducing the air flow rate and avoiding an increase in the amount of oxygen.

[0040] Exemplarily, the working condition under continuous working conditions is: there is flue gas from the combustion chamber 1 in the heat exchanger 4, and the flue gas heats the airflow in the airflow pipeline 3. The temperature sensor 5 detects that the airflow temperature is high. Under high temperature conditions, the oxygen content of the airflow is low, and the throttle valve 6 is coordinated to increase the opening, thereby increasing the airflow flow rate and avoiding a reduction in the amount of oxygen.

[0041] Embodiment 2:

[0042] Based on the above embodiment, another embodiment of the utility model is that a regulating valve is provided at the input end of the air supply device 2, and the regulating valve is used to adjust the output of the airflow. The regulating valve is an existing valve, and the airflow is provided at the input end of the air supply device 2, which can control the gas intake amount of the air supply device 2.

[0043] For reference, the air supply device 2 may be an existing electrically controlled fan, and the air flow rate of the air supply device 2 may be adjusted by a controller, so that the air supply device 2 itself directly controls the size of the air flow.

[0044] For reference, the air supply device 2 is connected to an oxygen-containing source, and a regulating valve is provided at the input end of the air supply device 2, and the input amount of the oxygen-containing source is controlled by the regulating valve.

[0045] Embodiment 3:

[0046] Based on the above embodiment, another embodiment of the utility model is that the temperature sensor 5 is connected to the throttle valve 6 control unit by signal, wherein the throttle valve 6 control unit can be an existing throttle valve actuator, and the temperature sensor 5 monitors the gas temperature in the airflow pipeline 3, and the temperature sensor 5 sends the temperature signal to the throttle valve 6 control unit, and the temperature sensor 5 sends the gas temperature data to the throttle valve 6 control unit in real time, and the throttle valve 6 control unit controls the opening and closing degree of the throttle valve 6. When the throttle valve 6 control unit receives the temperature signal, the opening of the throttle valve 6 can be accurately adjusted to ensure that the amount of air received by the burner 101 matches the temperature. The temperature sensor 5 is linked to the throttle valve 6 in real time, which is conducive to quickly responding to the air-fuel ratio requirements of the burner 101 and improving the stability and efficiency of combustion. At the same time, the throttle valve 6 control unit adopts the method of automatically adjusting the opening of the throttle valve 6, which has a good response speed and reduces the equipment damage that may be caused by improper human adjustment.

[0047] Exemplarily, when the device is working, the temperature sensor 5 collects the temperature information of the gas in the airflow pipeline 3 and converts the temperature information into an electrical signal. The temperature sensor 5 sends the converted electrical signal to the control unit of the throttle valve 6 through wires or wirelessly. After receiving the temperature signal, the control unit adjusts the opening of the throttle valve 6 according to a preset program.

[0048] For reference, the throttle valve 6 control unit adopts an existing throttle valve actuator, which changes the opening of the throttle valve 6 through electrical or mechanical action to control the air flow through the throttle valve 6. If necessary, the throttle valve actuator can also be set with working signal feedback, and the working signal is fed back to the host computer to ensure that the adjustment result meets the predetermined target, thereby achieving automatic closed-loop control.

[0049] Embodiment 4:

[0050] Based on the above embodiment, another embodiment of the utility model is that, in order to better control the airflow state, the airflow pipeline 3 includes a combustion-supporting pipeline 301 and an air supply pipeline 302. Since the heat is mainly concentrated in the combustion-supporting pipeline 301, the air supply pipeline 302 can maintain a relatively low temperature. The combustion-supporting pipeline 301 is connected to the output end of the cold pipe of the heat exchanger 4, and the air supply pipeline 302 is connected to the input end of the cold pipe of the heat exchanger 4. By separately setting the combustion-supporting pipeline 301 and the air supply pipeline 302, different airflow state controls can be performed at the input end and output end of the heat exchanger 4. Since the gas has been preheated by the heat exchanger 4 before entering the combustion-supporting pipeline, setting the combustion-supporting pipeline 301 and the air supply pipeline 302 to insulation and non-insulation respectively helps to reduce heat energy loss and help improve combustion efficiency and air-fuel ratio control.

[0051] For example, in order to ensure the air flow temperature in the air flow pipeline 3 after heat exchange in the heat exchanger 4, an insulation layer is provided on the outer wall of the combustion-supporting pipeline 301. In order to better control the cost, the air supply pipeline 302 is a normal pipeline.

[0052] Embodiment 5:

[0053] Based on the above embodiments, another embodiment of the utility model is, considering that if a part of the air supply device 2 adopts a fan with higher air tightness, the output of the airflow pipeline 3 is the same as the input of the airflow pipeline 3, and the throttle valve 6 reduces the opening, which usually can only affect the local position of the airflow pipeline 3, and the air-fuel ratio may not be adjusted significantly; in order to ensure that the throttle valve 6 can stably adjust the air flow of the airflow pipeline 3, a bypass pipeline is arranged on the above-mentioned airflow pipeline 3, and the bypass pipeline is located between the throttle valve 6 and the air supply device 2, and a solenoid valve is arranged on the above-mentioned bypass pipeline; when the air supply device 2 outputs a constant airflow, the above-mentioned solenoid valve is used to cooperate with the bypass pipeline to maintain the airflow pressure in the airflow pipeline 3 within a set range.

[0054] For reference, by setting a bypass pipeline and installing a solenoid valve therein, the solenoid valve is located between the throttle valve 6 and the air supply device 2, and the bypass pipeline cooperates with the solenoid valve for opening and closing, and under relatively sealed conditions, a constant airflow is allowed to be output from the air supply device 2, and when the throttle valve 6 reduces the opening of the local airflow pipeline 3, the solenoid valve on the bypass pipeline is opened and closed synchronously to maintain the airflow pressure in the airflow pipeline 3 always within the preset setting range. The airflow volume of the airflow pipeline 3 can be changed by the throttle valve 6.

[0055] For reference, when the air supply device 2 is abnormal, causing the air flow pressure to fluctuate, the bypass passage can play a balancing role and quickly adjust the pressure to meet the immediate air flow demand of the burner 101. Such a configuration improves the stability and reliability of the combustion process, ensures that the burner can operate in an optimized state, and thus improves the combustion efficiency and the overall performance of the equipment.

[0056] More importantly, the application of solenoid valves in the bypass line can achieve rapid response and provide more precise and rapid control compared to other types of flow regulating devices, making the airflow state in the airflow line 3 more controllable.

[0057] Embodiment 6:

[0058] Based on the above embodiments, reference Figure 3As shown, another embodiment of the utility model is that, in order to ensure the stable heat exchange of the heat exchanger 4, a first pipe 401 as a cold pipe and a second pipe 402 as a heat pipe are provided in the inner cavity of the heat exchanger 4, and the first pipe 401 and the second pipe 402 are heat exchanged; the airflow pipeline 3 is connected to the first pipe 401, and the flue gas pipeline 102 is connected to the second pipe 402. The heat exchanger 4 can ensure that the air sent to the burner 101 has been properly preheated through the airflow pipeline 3 and the first pipe 401, thereby improving the combustion effect and stability during cold start. At the same time, the flue gas pipeline 102 is connected to the second pipe 402, so that the exhaust flue gas can preheat the incoming air before leaving the combustion chamber 1, thereby improving the efficiency of the entire combustion process, reducing the exhaust gas emissions, and meeting the development trend of energy conservation and environmental protection.

[0059] Exemplarily, the inner cavity structure composed of the first pipe 401 as a cold pipe and the second pipe 402 as a heat pipe allows heat to be transferred between the first pipe 401 and the second pipe 402, avoiding direct contact between the flue gas and the airflow. When the flue gas passes through the second pipe 402, the heat in the flue gas is transferred to the first pipe 401 through the wall of the pipe, wherein the gas flowing in the first pipe 401 is preheated by absorbing the heat energy of the second pipe 402. Using the heat in the flue gas to preheat the air entering the burner helps to improve energy efficiency and reduce operating costs, further improving the thermal energy utilization efficiency of the entire system.

[0060] Furthermore, the first pipe 401 and the second pipe 402 are distributed in a serpentine shape, and the serpentine pipe is used to provide a longer flow path and a larger heat exchange area. The side wall of the first pipe 401 and the side wall of the second pipe 402 are close to each other; wherein, the area where the first pipe 401 and the second pipe 402 are close to each other adopts heat-conducting material and serves as a heat-conducting surface. The heat-conducting material is used as a heat-conducting surface in the area where they are close to each other, so that heat has enough time and space to be transferred, thereby improving the efficiency of heat exchange.

[0061] For reference, the use of heat-conducting materials can promote uniform distribution of heat, avoid excessively high or low temperatures in some areas, and thus make the temperature distribution of preheated air more uniform. In addition to the heat-conducting surfaces of the first pipe 401 and the second pipe 402, the rest of the pipe can use heat-insulating materials to ensure that the heat exchanger still maintains good performance and stable heat exchange under high temperature conditions.

[0062] For reference, the first pipe 401 and the second pipe 402 in the heat exchanger 4 are arranged in a serpentine shape and close to each other to increase the contact area between the two and improve the heat exchange efficiency. At the same time, the serpentine pipe design allows the heat exchanger to provide a larger heat exchange area in a limited space, which makes the overall size of the heat exchanger more compact and easier to integrate and maintain.

[0063] Embodiment 7:

[0064] Based on the above embodiments, reference Figure 3 and Figure 4 As shown, another embodiment of the utility model is that a heat exchange sheet 403 is provided between the first pipe 401 and the second pipe 402, wherein the heat exchange sheet 403 is made of a heat-conducting material as a whole, and both sides of the heat exchange sheet 403 are attached to heat-conducting surfaces, and the heat exchange sheet 403 performs heat transfer between the first pipe 401 and the second pipe 402. The heat exchange sheet 403 can effectively promote the heat transfer between the first pipe 401 and the second pipe 402.

[0065] Specifically, the heat exchange sheet 403 directly adheres to the heat conducting surface, which can enhance the overall stability of the internal structure of the heat exchanger, and at the same time reduce the thermal expansion and contraction of the internal components caused by temperature changes, and reduce material fatigue. Secondly, considering that the heat exchange temperature of the contact part of the first pipe 401 and the second pipe 402 may be different, the heat exchange efficiency can be significantly improved by increasing the area of ​​direct contact with the hot and cold pipes through the heat exchange sheet 403. Heat can be transferred and dispersed faster, making the gas heating or cooling process more rapid and uniform.

[0066] Furthermore, a heat conducting needle 404 is disposed outside the heat exchange plate 403, and the heat conducting needle 404 extends to the inner cavity of the first pipe 401 and the inner cavity of the second pipe 402. The heat exchange plate 403 is provided with the heat conducting needle 404 to increase the heat exchange area, and the heat conducting needle 404 can perform heat exchange in the inner cavity of the first pipe 401 and the inner cavity of the second pipe 402, thereby improving the heat exchange efficiency.

[0067] It is worth noting that the sizes of the inner cavities of the first pipe 401 and the second pipe 402 of the heat conductive needle 404 are limited, and usually will not directly affect the movement of the fluids in the first pipe 401 and the second pipe 402 .

[0068] The "one embodiment", "another embodiment", "embodiment", "preferred embodiment" and the like mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0069] Although the utility model is described herein with reference to a plurality of illustrative embodiments of the utility model, it should be understood that those skilled in the art may devise many other modifications and implementations that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the disclosure, drawings, and claims of the present application, various modifications and improvements may be made to the components and / or layout of the subject combination layout. In addition to the modifications and improvements made to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A device for correcting the air-fuel ratio of a premix burner during cold start, comprising a combustion chamber (1), wherein a burner (101) is arranged in the combustion chamber (1), and a flue gas duct (102) is arranged on the combustion chamber (1), wherein the flue gas duct (102) is used to output the flue gas in the combustion chamber (1); characterized in that: Also includes: An air supply device (2), wherein an air flow pipeline (3) connected to the burner (101) is provided at the output end of the air supply device (2), and the air supply device (2) delivers air flow to the burner (101) through the air flow pipeline (3); The airflow pipeline (3) and the flue gas pipeline (102) are respectively connected to the cold pipe and the hot pipe of the heat exchanger (4), and the heat exchanger (4) enables heat exchange between the flue gas pipeline (102) and the airflow pipeline (3); A temperature sensor (5) is arranged on the airflow pipeline (3), and the temperature sensor (5) is used to collect the temperature of the airflow flowing to the burner (101) on the airflow pipeline (3); a throttle valve (6) is arranged on the airflow pipeline (3), and the throttle valve (6) is used to adjust the ventilation volume of the airflow pipeline (3) according to the airflow temperature.

2. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 1, characterized in that: The input end of the air supply device (2) is provided with a regulating valve, and the regulating valve is used to adjust the output of the air flow.

3. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 1, characterized in that: The temperature sensor (5) is connected to a throttle valve (6) control unit by signal. The temperature sensor (5) sends a temperature signal to the throttle valve (6) control unit, and the throttle valve (6) control unit controls the opening and closing degree of the throttle valve (6).

4. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 1, characterized in that: The air flow pipeline (3) comprises a combustion-supporting pipeline (301) and an air supply pipeline (302); the combustion-supporting pipeline (301) is connected to the output end of the cold pipe of the heat exchanger (4); and the air supply pipeline (302) is connected to the input end of the cold pipe of the heat exchanger (4).

5. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 2, characterized in that: A bypass pipeline is provided on the airflow pipeline (3), and the bypass pipeline is located between the throttle valve (6) and the air supply device (2). A solenoid valve is provided on the bypass pipeline; when the air supply device (2) outputs a constant airflow, the solenoid valve is used to cooperate with the bypass pipeline to maintain the airflow pressure in the airflow pipeline (3) within a set range.

6. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 1, characterized in that: A first pipe (401) serving as a cold pipe and a second pipe (402) serving as a hot pipe are provided in the inner cavity of the heat exchanger (4), and the first pipe (401) and the second pipe (402) perform heat exchange; the air flow pipeline (3) is connected to the first pipe (401), and the flue gas pipeline (102) is connected to the second pipe (402).

7. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 6, characterized in that: The first pipe (401) and the second pipe (402) are distributed in a serpentine shape, and the side wall of the first pipe (401) and the side wall of the second pipe (402) are close to each other; wherein the area where the first pipe (401) and the second pipe (402) are close to each other is made of heat-conducting material and serves as a heat-conducting surface.

8. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 7, characterized in that: A heat exchange plate (403) is provided between the first pipe (401) and the second pipe (402), and both sides of the heat exchange plate (403) are in contact with heat conductive surfaces. The heat exchange plate (403) transfers heat between the first pipe (401) and the second pipe (402).

9. The device for correcting the air-fuel ratio of a premixed burner during cold start according to claim 8, characterized in that: A heat conducting needle (404) is disposed outside the heat exchange plate (403), and the heat conducting needle (404) extends to the inner cavity of the first pipe (401) and the inner cavity of the second pipe (402), respectively.

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