Low-concentration gas combustion system based on graded preheating
By using a closed-loop system of thermal oil heater and gas preheater, along with a waste heat recovery device, the problem of high energy consumption in traditional electric heating methods is solved, enabling efficient and low-cost operation of the low-concentration gas combustion system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING JUNFA COMBUSTIBLE GAS TECH DEV CO LTD
- Filing Date
- 2025-06-04
- Publication Date
- 2026-05-01
AI Technical Summary
Traditional low-concentration gas combustion systems use electric heating preheating, which consumes a lot of energy and results in high costs.
A closed loop is formed by using a thermal oil heater and a gas preheater. Preheating is achieved through indirect heat exchange between the thermal oil and low-concentration gas. Combined with a waste heat recovery device and a staged preheating design, energy loss is reduced.
It improves energy efficiency, reduces energy consumption and operating costs of the combustion system, and ensures the stability and efficiency of the combustion process.
Smart Images
Figure CN224188604U_ABST
Abstract
Description
Low-concentration gas combustion system based on staged preheating Technical Field
[0001] This application relates to the field of low-concentration gas technology, and in particular to a low-concentration gas combustion system based on staged preheating. Background Technology
[0002] In traditional gas combustion systems, low-concentration gas is usually preheated in order to ensure its successful combustion in a regenerative ignition device. However, most existing gas combustion systems use electric heating to preheat low-concentration gas. Electric heating directly converts electrical energy into heat energy, which can effectively increase the temperature of low-concentration gas, but its energy consumption is high, which is not conducive to reducing the cost of the combustion system. Summary of the Invention
[0003] In view of this, this application proposes a low-concentration gas combustion system based on staged preheating, comprising: a first conveying unit, a gas preheater, a thermal oil heater, and a regenerative ignition device;
[0004] The feed end of the first conveying unit is suitable for connecting to the outlet of low-concentration gas, the discharge end of the first conveying unit is connected to the feed end of the regenerative ignition device, and the gas preheater is installed on the pipeline of the first conveying unit. The gas preheater is suitable for preheating the low-concentration gas introduced by the first conveying unit.
[0005] The outlet of the thermal oil heater is connected to the inlet of the gas preheater. The thermal oil heater is suitable for providing a heat source for the gas preheater. The outlet of the gas preheater is connected to the inlet of the thermal oil heater to form a closed thermal oil circulation.
[0006] One possible implementation also includes: a separator and an expansion tank;
[0007] The separator is located between the outlet of the gas preheater and the inlet of the thermal oil heater, and the expansion tank is located at the exhaust port of the separator.
[0008] In one possible implementation, the regenerative ignition device includes a combustion chamber, a regenerator, and an ignition gun.
[0009] The ignition gun is mounted on the combustion chamber, with the ignition end of the ignition gun protruding into the cavity of the combustion chamber. The heat storage body is located inside the cavity of the combustion chamber.
[0010] In one possible implementation, a waste heat recovery device;
[0011] The input end of the waste heat recovery device is connected to the output end of the combustion chamber, and the output end of the waste heat recovery device is connected to the inlet of the gas preheater.
[0012] In one possible implementation, a temperature sensor is installed in the combustion chamber; the temperature sensor is electrically connected to the thermal oil heater via a controller.
[0013] In one possible implementation, a second conveying unit is also included; the inlet of the second conveying unit is connected to the outlet of the low-concentration gas, and the outlet of the second conveying unit is connected to the inlet of the regenerative ignition device, so as to divert the low-concentration gas by cooperating with the first conveying unit through the second conveying unit.
[0014] In one possible implementation, both the first conveying unit and the second conveying unit include: a flow regulating element and a mixing chamber;
[0015] The discharge end of the flow regulator is connected to the feed end of the mixing chamber, and the gas preheater is installed between the flow regulator and the mixing chamber.
[0016] One possible implementation method also includes a gas splitter;
[0017] The gas diverter is suitable for installation at the outlet of low-concentration gas, located between the outlet of low-concentration gas and the feed end of the first conveying unit.
[0018] In one possible implementation, a blower is also included; the output of the blower is connected to the cavity of the mixing chamber.
[0019] Beneficial effects of this application
[0020] This application preheats low-concentration gas by setting up a gas preheater and a thermal oil heater, and using circulating thermal oil for heat exchange. The thermal oil has a high heat capacity and good heat transfer performance, and can efficiently absorb and release heat during circulation. After the thermal oil is heated in the thermal oil heater, the thermal oil carrying a large amount of heat energy exchanges heat with the low-concentration gas in the gas preheater, thereby achieving the preheating of the low-concentration gas. Compared with the traditional electric heating method, this indirect heat exchange method avoids the energy loss in the process of directly converting electrical energy into heat energy, improves energy utilization efficiency, reduces the energy consumption of the combustion system, and thus reduces the operating cost of the combustion system.
[0021] Other features and aspects of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description
[0022] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this application together with the specification and serve to explain the principles of this application.
[0023] Figure 1 shows a schematic diagram of the structural connection relationship of a low-concentration gas combustion system according to an embodiment of this application.
[0024] First conveying unit—100; Gas distributor—110; Flow regulator—120; Mixing chamber—130; Double shut-off valve—140; Gas preheater—210; Thermal oil heater—220; Separator—230; Expansion tank—240; Circulating pump—250; Shut-off valve—260; Detection device—270; Regenerative ignition device—300; Combustion chamber—310; Heat storage body—320; Ignition gun—330; Liquefied petroleum gas—331; Temperature sensor—340; Waste heat recovery device—400; Second conveying unit—500; Blower—610; Silencer—620. Detailed Implementation
[0025] Various exemplary embodiments, features, and aspects of this application will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.
[0026] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0028] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.
[0029] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented without certain specific details. In some instances, methods, means, components, and circuits well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.
[0030] This application proposes a low-concentration gas combustion system based on staged preheating, including a first conveying unit 100, a gas preheater 210, a thermal oil heater 220, and a regenerative ignition device. The feed end of the first conveying unit 100 is adapted to be connected to the outlet of low-concentration gas, and the discharge end of the first conveying unit 100 is connected to the feed end of the regenerative ignition device. The gas preheater 210 is installed on the pipeline of the first conveying unit 100 and is adapted to preheat the low-concentration gas introduced by the first conveying unit 100. The outlet of the thermal oil heater 220 is connected to the inlet of the gas preheater 210 and is adapted to provide a heat source for the gas preheater 210. The outlet of the gas preheater 210 is connected to the inlet of the thermal oil heater 220 to form a closed thermal oil circulation.
[0031] It should be noted that this application is particularly suitable for igniting low-concentration methane (4%). The first conveying unit 100 serves as a transmission channel for the low-concentration methane, suitable for introducing the low-concentration methane into the combustion system of this application and conveying it to the regenerative ignition device; the methane preheater 210 is suitable for preheating the low-concentration methane, so that the low-concentration methane reaches a preset temperature before entering the regenerative ignition device, thereby increasing the thermal activity of methane molecules in the low-concentration methane, enhancing the collision frequency and energy between methane molecules and oxygen molecules, and ensuring... The regenerative ignition device ensures that low-concentration methane undergoes complete combustion within the device. The thermal oil heater 220 provides a heat source for the gas preheater 210, which serves as a heat exchange component between the thermal oil and the low-concentration methane. The high-temperature thermal oil heats the low-concentration methane flowing through the gas preheater 210 from the first conveying unit 100. The regenerative ignition device is designed to rapidly ignite the low-concentration methane entering it. Simultaneously, the regenerative ignition device stores heat through heat storage materials, enabling it to continuously provide heat for the combustion process after ignition, thus ensuring the stability of the combustion process.
[0032] When low-concentration gas flows through the gas preheater 210, the high-temperature heat transfer oil provided by the heat transfer oil heater 220 transfers heat to the low-concentration gas through the gas preheater 210, raising the temperature of the low-concentration gas from room temperature to a preset temperature. After heat exchange in the gas preheater 210, the temperature of the heat transfer oil decreases and it returns to the heat transfer oil heater 220. In the heat transfer oil heater 220, the heat transfer oil is reheated to a high temperature and re-enters the gas preheater 210, forming a closed loop. The closed-loop heat transfer oil circulation design ensures efficient heat transfer and utilization, reduces heat loss, and improves energy efficiency. By preheating the low-concentration gas through the gas preheater 210, the thermal motion activity of the gas molecules in the low-concentration gas is increased, thereby increasing the collision frequency between gas molecules and oxygen molecules. This allows the low-concentration gas to undergo a complete combustion reaction in the regenerative ignition device, reducing incomplete combustion of the low-concentration gas, improving the combustion efficiency of the low-concentration gas, and reducing energy waste. The preset temperature range is 195°C to 205°C.
[0033] This application preheats low-concentration gas by setting up a gas preheater 210 and a thermal oil heater 220, and using circulating thermal oil for heat exchange. The thermal oil has a high heat capacity and good heat transfer performance, and can efficiently absorb and release heat during circulation. When the thermal oil is heated in the thermal oil heater 220, the thermal oil carrying a large amount of heat energy exchanges heat with the low-concentration gas in the gas preheater 210, thereby achieving the preheating of low-concentration gas. Compared with the traditional electric heating method, this indirect heat exchange method avoids the energy loss in the process of directly converting electrical energy into heat energy, improves energy utilization efficiency, reduces the energy consumption of the combustion system, and thus reduces the operating cost of the combustion system.
[0034] In one possible implementation, the gas preheater 210 is an explosion-proof shell-and-tube heat exchanger; the internal pipes of the shell-and-tube heat exchanger are used for the flow of low-concentration gas, while the shell side is used for the circulation of heat transfer oil; this structure enables the heat transfer oil and low-concentration gas to exchange heat efficiently through the pipe walls; furthermore, the pipes of the gas preheater 210 can be made of copper tubes with good thermal conductivity to enhance heat transfer efficiency.
[0035] Furthermore, in order to increase the heat transfer area, fins or the like can be installed inside or outside the gas preheater 210, thereby increasing the heat exchange area between low-concentration gas and heat transfer oil, improving preheating efficiency, and shortening the heating time of low-concentration gas.
[0036] In one possible implementation, the thermal oil heater 220 can be a finned or shell-and-tube heater, a type already available in the art; the operator can control the temperature of the thermal oil according to the actual need for preheating low-concentration gas. Preferably, the thermal oil needs to be heated to 200°C–230°C.
[0037] In one possible implementation, the system further includes a separator 230 and an expansion tank 240. The separator 230 is positioned between the outlet of the gas preheater 210 and the inlet of the thermal oil heater 220, while the expansion tank 240 is located at the exhaust port of the separator 230. It should be noted that the high-temperature thermal oil exchanges heat with low-concentration gas in the gas preheater 210 to heat the gas to the target temperature. The cooled thermal oil then enters the separator 230, where it separates gaseous impurities from the thermal oil using gravity or centrifugal force, thus ensuring the thermal transfer efficiency of the thermal oil and improving its utilization efficiency. The expansion tank 240 is suitable for treating and discharging the gaseous impurities separated by the separator 230, preventing them from being directly released into the environment and reducing environmental pollution.
[0038] In one possible implementation, a circulation pump 250 is also included. The circulation pump 250 is located at the inlet of the thermal oil heater 220 and between the separator 230 and the thermal oil heater 220. The circulation pump 250 drives the thermal oil to circulate continuously in a closed loop through mechanical power, so as to avoid insufficient heat transfer caused by the low natural convection efficiency of the thermal oil and ensure the uniformity and stability of the flow rate and velocity of the thermal oil.
[0039] In one possible implementation, both the inlet and outlet ends of the thermal oil heater 220 are equipped with shut-off valves 260, and the opening and closing of the thermal oil heater 220 circulation is achieved by closing or opening the shut-off valves 260.
[0040] Furthermore, it also includes a detection device 270, which is installed at the outlet of the heat transfer oil heater 220. The detection device 270 includes a temperature alarm, a pressure detector, and a flow detector, which are arranged sequentially along the flow direction of the heat transfer oil.
[0041] In one possible implementation, the regenerative ignition device includes a combustion chamber 310, a heat storage body 320, and an ignition gun 330; the ignition gun 330 is disposed on the combustion chamber 310, and the ignition end of the ignition gun 330 extends into the cavity of the combustion chamber 310, and the heat storage body 320 is disposed in the cavity of the combustion chamber 310.
[0042] It should be noted that the combustion chamber 310 provides sufficient space for the combustion reaction of the mixture of gas and the combustion medium; the heat storage body 320 absorbs and stores heat during the combustion of low-concentration gas, and releases the stored heat when the temperature inside the combustion chamber 310 drops to 650°C. The characteristics of the heat storage body 320 enable the temperature inside the combustion chamber 310 to be maintained at a relatively stable level, reducing temperature fluctuations during the combustion of low-concentration gas and ensuring the uniformity and stability of the combustion process; the ignition gun 330 provides ignition energy for the low-concentration gas inside the combustion chamber 310 by igniting the liquefied gas 331, ensuring that the gas can be ignited quickly and avoiding combustion interruption or flameout due to insufficient ignition.
[0043] Furthermore, the heat storage body 320 is a honeycomb ceramic heat storage body 320. The honeycomb structure of the heat storage body 320 allows heat to be released or stored quickly, while providing a large contact area to promote the uniform distribution of heat. The heat storage body 320 made of ceramic material has a high heat capacity, which can store a large amount of heat and release it gradually during combustion, ensuring the temperature in the combustion chamber is stable.
[0044] In one possible implementation, a waste heat recovery device 400 is also included; the input end of the waste heat recovery device 400 is connected to the output end of the combustion chamber 310, and the output end of the waste heat recovery device 400 is connected to the inlet of the gas preheater 210. It should be noted that the waste heat recovery device 400 is suitable for extracting heat from the high-temperature flue gas discharged from the combustion chamber 310 and transferring the heat to the gas preheater 210 for heat exchange with the low-concentration gas within the gas preheater 210. This avoids heat waste caused by direct emission of high-temperature flue gas. Simultaneously, the high-temperature waste heat recovery design reduces dependence on traditional energy sources, improves energy utilization efficiency, and reduces environmental pollution caused by the emission of harmful substances.
[0045] Furthermore, the waste heat recovery device 400 is a waste heat recovery boiler in the prior art.
[0046] In one possible implementation, a temperature sensor 340 is provided in the combustion chamber 310; the temperature sensor 340 is electrically connected to the thermal oil heater 220 via a controller.
[0047] It should be noted that the temperature sensor 340 is used to detect temperature changes in the combustion chamber 310 and transmits the detected temperature data to the controller. The controller controls the thermal oil heater 220 to turn on and off based on the received temperature, thereby realizing the switching between the thermal oil heater 220 and the waste heat recovery device 400. Specifically, the switching between the thermal oil heater 220 and the waste heat recovery device 400 is based on whether the temperature detected by the temperature sensor 340 meets the set temperature threshold. When the temperature detected by the temperature sensor 340 is lower than the set temperature threshold, the controller starts the thermal oil heater 220 to provide heat energy to the gas preheater 210, ensuring that the low-concentration gas reaches a suitable preheating temperature before entering the combustion chamber 310. When the temperature detected by the temperature sensor 340 reaches the set temperature threshold, the controller shuts off the thermal oil heater 220 and switches to the waste heat recovery device 400. At this time, the waste heat recovery device 400 uses the high-temperature flue gas in the combustion chamber 310 to preheat the low-concentration gas in the gas preheater 210, thereby reducing the dependence on the thermal oil heater 220 and further improving energy utilization efficiency. Through this intelligent switching mechanism, the low-concentration gas combustion system can automatically optimize energy utilization under different operating conditions, ensuring the high efficiency and stability of the low-concentration gas combustion process, while reducing operating costs and energy consumption.
[0048] Furthermore, the temperature threshold is set to ≥650℃.
[0049] In one possible implementation, a second conveying unit 500 is also included. The inlet of the second conveying unit 500 is connected to the outlet of the low-concentration gas, and the outlet of the second conveying unit 500 is connected to the inlet of the heat storage ignition device, so that the low-concentration gas is diverted through the cooperation of the second conveying unit 500 and the first conveying unit 100. It should be noted that the first conveying unit 100 and the second conveying unit 500 are arranged in parallel; the second conveying unit 500 is suitable for directly conveying low-concentration gas at room temperature. The cooperation of the second conveying unit 500 and the first conveying unit 100 to divert the low-concentration gas forms a staged preheating design; wherein, the staged preheating design includes a preheating stage, a heat storage transition stage, and a steady-state operation stage, specifically:
[0050] During the preheating stage, the gas distributor 110 diverts 15% of the low-concentration gas to the first conveying unit 100. The gas preheater 210 exchanges heat with the low-concentration gas through circulating heat transfer oil. The heated low-concentration gas is then conveyed to the combustion chamber 310 through the first conveying unit 100. The ignition gun 330 ignites the preheated low-concentration gas in the combustion chamber 310. Subsequently, the combustion system enters the heat storage transition stage. The ignited low-concentration gas burns in the combustion chamber 310, generating a large amount of heat energy. The heat storage body 320 in the combustion chamber 310 absorbs and stores the heat energy generated during the combustion of the low-concentration gas. When the heat storage body 320... When the temperature reaches 550℃, the second conveying unit 500 begins to gradually convey low-concentration gas at room temperature into the combustion chamber 310. At this time, as the low-concentration gas at room temperature burns, the temperature in the combustion chamber 310 continues to rise. When the temperature in the combustion chamber 310 reaches 650℃, the combustion system enters a steady-state operation. At this time, the heat transfer oil heater 220 is turned off and switched to the waste heat recovery device 400. The waste heat recovery device 400 recovers the high-temperature flue gas in the combustion chamber 310 and uses the high-temperature flue gas in the combustion chamber 310 to maintain the preheating of the low-concentration gas in the gas preheater 210.
[0051] By using a staged preheating method, during the start-up phase of the combustion system, the gas preheater 210 rapidly raises the temperature of low-concentration gas through circulating heat transfer oil, reducing the start-up time of the combustion system. Then, when the temperature of the combustion chamber 310 reaches 650°C, the heat transfer oil heater 220 is shut down and the waste heat recovery device 400 is switched on. The high-temperature flue gas in the combustion chamber 310 is used to preheat the low-concentration gas, reducing the dependence on the heat transfer oil heater 220 and the input of external energy, improving energy utilization and reducing operating costs.
[0052] In one possible implementation, the second conveying unit 500 is provided with two or more second conveying units 500 connected in parallel.
[0053] In one possible implementation, both the first conveying unit 100 and the second conveying unit 500 include a flow regulating element 120 and a mixing chamber 130; the discharge end of the flow regulating element 120 is connected to the feed end of the mixing chamber 130, and the gas preheater 210 is installed between the flow regulating element 120 and the mixing chamber 130.
[0054] It should be noted that the flow regulator 120 is used to control the flow rate of low-concentration gas entering the mixing chamber 130. The operator can flexibly adjust the supply of low-concentration gas according to the combustion requirements or changes in operating conditions to ensure the stability and safety of the combustion process. The mixing chamber 130 provides sufficient mixing space for low-concentration gas and the medium required for combustion. The gas preheater 210 is installed between the flow regulator 120 of the first conveying unit 100 and the mixing chamber 130, so that the low-concentration gas conveyed by the first conveying unit 100 is preheated before entering the mixing chamber 130, ensuring that the gas reaches the optimal preheating temperature when entering the mixing chamber 130.
[0055] Furthermore, both the first conveying unit 100 and the second conveying unit 500 include a double shut-off valve 140. The double shut-off valve 140 of the first conveying unit 100 is disposed between the gas preheater 210 and the flow regulating component 120, and the double shut-off valve 140 of the second conveying unit 500 is disposed between the flow regulating component 120 and the mixing chamber 130.
[0056] In one possible implementation, a gas diverter 110 is also included. The gas diverter 110 is suitable for installation at the outlet of the low-concentration gas, located between the outlet of the low-concentration gas and the feed end of the first conveying unit 100. It should be noted that the gas diverter 110 is suitable for diverting a certain amount of low-concentration gas to the first conveying unit 100 according to a preset diversion ratio, thereby realizing the graded utilization or treatment of low-concentration gas and improving the comprehensive utilization efficiency of low-concentration gas. By setting the gas separator 230, the amount of gas entering the first conveying unit 100 can be flexibly adjusted. Specifically, the diversion ratio of the gas diverter 110 refers to the ratio of the gas flow rate diverted to the first conveying unit 100 by the gas diverter 110 to the total gas flow rate during the low-concentration gas conveying process.
[0057] Furthermore, the value range of the gas diverter 110 diversion ratio is 10%-20%; preferably, the value of the gas diverter 110 diversion ratio is 15%.
[0058] In one possible implementation, a blower device 610 is also included; the output end of the blower device 610 is connected to the cavity of the mixing chamber 130. It should be noted that the blower device 610, with its output end connected to the cavity of the mixing chamber 130, is suitable for providing sufficient airflow to the mixing chamber 130, thereby ensuring thorough mixing of the low-concentration gas with the combustion medium, preventing backfire or explosion due to excessively high gas concentration, and ensuring the safety of the low-concentration gas combustion process.
[0059] Furthermore, the blower device 610 is a blower.
[0060] Furthermore, a silencer 620 is installed on the blower. The silencer 620 can effectively absorb and reduce the aerodynamic noise generated during the operation of the blower, reduce noise pollution, and reduce the impact of noise on the surrounding environment.
[0061] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A low-concentration gas combustion system based on staged preheating, characterized in that, include: The system comprises a first conveying unit, a gas preheater, a thermal oil heater, and a regenerative ignition device. The inlet of the first conveying unit is connected to the outlet of a low-concentration gas source, and the outlet of the first conveying unit is connected to the inlet of the regenerative ignition device. The gas preheater is installed on the pipeline of the first conveying unit and is used to preheat the low-concentration gas introduced by the first conveying unit. The outlet of the thermal oil heater is connected to the inlet of the gas preheater and is used to provide a heat source for the gas preheater. The outlet of the gas preheater is connected to the inlet of the thermal oil heater to form a closed-loop thermal oil circulation.
2. The low-concentration gas combustion system based on staged preheating according to claim 1, characterized in that, Also includes: A separator and an expansion tank; the separator is located between the outlet of the gas preheater and the inlet of the thermal oil heater, and the expansion tank is located at the exhaust port of the separator.
3. The low-concentration gas combustion system based on staged preheating according to claim 1, characterized in that, The regenerative ignition device includes a combustion chamber, a heat storage body, and an ignition gun; the ignition gun is disposed on the combustion chamber, and the ignition end of the ignition gun extends into the cavity of the combustion chamber, and the heat storage body is disposed in the cavity of the combustion chamber.
4. The low-concentration gas combustion system based on staged preheating according to claim 3, characterized in that, It also includes a waste heat recovery device; the input end of the waste heat recovery device is connected to the output end of the combustion chamber, and the output end of the waste heat recovery device is connected to the inlet of the gas preheater.
5. The low-concentration gas combustion system based on staged preheating according to claim 4, characterized in that, A temperature sensor is installed in the combustion chamber; the temperature sensor is electrically connected to the heat transfer oil heater via a controller.
6. The low-concentration gas combustion system based on staged preheating according to claim 1, characterized in that, It also includes a second conveying unit; the inlet of the second conveying unit is connected to the outlet of the low-concentration gas, and the outlet of the second conveying unit is connected to the inlet of the regenerative ignition device, so as to divert the low-concentration gas by cooperating with the first conveying unit through the second conveying unit.
7. The low-concentration gas combustion system based on staged preheating according to claim 6, characterized in that, Both the first conveying unit and the second conveying unit include a flow regulating component and a mixing chamber; the discharge end of the flow regulating component is connected to the feed end of the mixing chamber, and the gas preheater is installed between the flow regulating component and the mixing chamber.
8. The low-concentration gas combustion system based on staged preheating according to claim 6, characterized in that, It also includes a gas diverter; the gas diverter is suitable for installation at the outlet of the low-concentration gas, located between the outlet of the low-concentration gas and the feed end of the first conveying unit.
9. The low-concentration gas combustion system based on staged preheating according to claim 7, characterized in that, It also includes a blower; the output end of the blower is connected to the cavity of the mixing chamber.